CN1815507A - Method, apparatus, and medium for transforming graphic data of an object - Google Patents

Abstract

A method, apparatus, and medium for transforming a graphic data of an object and a computer readable recording medium storing a program for executing the method are provided. The method includes; determining at least one triangle to be collapsed among one or more triangles comprised in the object, determining a collapsing vertex to be created by collapsing the at least one triangle, and transforming the graphic data of the object based on information regarding the at least one triangle determined to be collapsed and information regarding the determined collapsing vertex. Thus, a large three-dimensional object can be efficiently rendered with a small amount of resources.

Description

The method of the graph data of transforming object, equipment and medium

Technical field

The present invention relates to a kind of method, equipment and medium of graph data of transforming object, and storage is used to carry out the computer readable recording medium storing program for performing of the program of described method.

Background technology

Figure 1A to Fig. 1 C is the diagrammatic sketch of the level of detail (LOD) that is used to explain object.Cone shape shown in Figure 1A.Leftmost cone shape is not in fact a cone, and it is near having the pyramidal shape on 4 planes.Middle cone shape has 8 planes, and rightmost cone shape has 16 planes.According to the direction of light from each reflection of three cone shapes, three cone shapes shown in Figure 1A differ from one another.

Figure 1B illustrates from three cone shapes of Figure 1A of farther distance observation.The cone shape difference of leftmost cone shape and rightmost cone shape and centre can be come.Yet, be difficult to clearly to discern the difference between rightmost cone shape and the middle cone shape.

Fig. 1 C illustrates three cone shapes of the Figure 1A that observes from much farther distance.In this case, can discern three difference between the cone shape hardly.

Such image sequence proves: along with the distance between object and the observer increases, will be difficult to the details of identifying object more.This expression is when object is viewed from larger distance, and the details of not all object all needs drawn come out.When the shape of object becomes complicated more, need more task to draw this object.Therefore, when the observer is far away apart from object, unnecessary this object of detailed drafting.

Three-dimensional data can not effectively be played up with Limited resources too greatly.Therefore, a kind of user's of consideration of expectation the progressive of position played up.

Summary of the invention

Others of the present invention, characteristics and/or advantage will partly be set forth in the following description, and will become clear from describe, and maybe can be understood by realization of the present invention.

The invention provides a kind of method and apparatus that is used for the graph data of the transforming object played up effectively with Limited resources by its three dimensional object, and a kind of storage is used to carry out the computer readable recording medium storing program for performing of the program of this method.

According to an aspect of the present invention, provide a kind of conversion to comprise the method for the graph data of at least one leg-of-mutton object.This method comprises: definite at least one triangle that will be subsided at least one triangle in being included in object; Determining will be by the summit that subsides that described at least one triangle is subsided and creates; And based on coming the graph data of transforming object about definite described at least one the leg-of-mutton information that will be subsided and about the information on definite summit that subsides.

Determine that described at least one triangle that will be subsided comprises: when definite triangle in being included in object is removed object is played up the minimum parameter of influence; And determine described at least one triangle that will be subsided based on described parameter.

The summit of determining to subside can comprise: the tangent plane based on leg-of-mutton three summits of described at least one that will be subsided and described three summits calculates the summit that subsides.In addition, the summit of determining to subside can comprise: calculate the attribute information on the summit that subsides based on leg-of-mutton three summits of described at least one that will be subsided.

A kind of method of graph data of transforming object adaptively is provided according to a further aspect in the invention.This method can comprise: receive and to comprise about the information on the summit of object and comprise the graphical model of one or more leg-of-mutton objects about at least one the leg-of-mutton information in the object of being included in expression; Determine at least one triangle that to be subsided in the triangle in being included in object, and determine will be by the summit that subsides that described at least one triangle is subsided and creates; Establishment comprises about at least one leg-of-mutton information of determining to be subsided with about the graphical model of the information on the summit that subsides determined; Come the graph data of transforming object based on the graphical model of creating; And play up this object.

Determine at least one triangle and the summit that subsides can comprise: definition is included in each triangle in the object is played up the effect of generation to object the error metrics of designator as indication; Based on error metrics to being included in each the triangle error of calculation value in the object; And determine that based on the error amount that calculates at least one triangle and the triangle that will be subsided subside in proper order.

According to a further aspect in the invention, provide a kind of conversion adaptively to comprise the method for the graph data of one or more leg-of-mutton objects.This method comprises: definition is included in each triangle in the object is played up the effect of generation to object the error metrics of designator as indication; Based on error metrics to being included in the triangle error of calculation value in the object; And at first the triangle that has minimum error values in the error amount that calculates is subsided.

The definition error metrics can comprise: definition as about the sum of errors of each leg-of-mutton geometric properties about the error of leg-of-mutton attributive character and error metrics.

At least one that can whether be positioned at the border based on the leg-of-mutton zone in leg-of-mutton radius-of-curvature, the whole grid (mesh) and this triangle determined the error about each leg-of-mutton geometric properties.Can determine error based at least one of the variation of the change in color between triangle and the adjacent triangle, the variation of texture coordinate value between them and the normal between them about leg-of-mutton attributive character.

Diabolo subsides and can comprise: create the summit that subsides to replace triangle; Change annexation between the triangle in being included in object based on the summit that subsides; And the new graph data of creating object based on the annexation that changes.

According to a further aspect in the invention, provide a kind of in being represented as the object that comprises one or more leg-of-mutton graph datas, triangle being subsided to be the method on summit.This method comprises: for each of leg-of-mutton three summits that will be subsided is defined in normal on the surface mesh; Be leg-of-mutton each summit definition tangent plane, this tangent plane comprises described summit and vertical with normal corresponding to this summit; The central point on leg-of-mutton three summits is projected on three tangent planes into each definition on described three summits, thereby obtain three subpoints; With the summit that subsides by the mean value acquisition of calculating three subpoints.

According to a further aspect in the invention, provide a kind of method of creating graphical model, described graphical model is used for the graph data that comprises a plurality of leg-of-mutton objects is carried out adaptive transformation.This method comprises: determine the summit that subsides that triangle, the triangle that will be subsided in object subside order and will subside and create by diabolo; Produce triangle identifier node, in this node, about being included in leg-of-mutton information in the object by the triangle series arrangement of subsiding; Generation comprises subside level of detail (LOD) the order node of order information of triangle; Produce the coordinate node, in this node, be arranged with the coordinate information on summit of object and the coordinate information on the summit that subsides; With the generation vertex position node that subsides, this node relates to the position of the coordinate information of the node that subsides that is arranged in the coordinate node.

Describedly determine and can comprise: for each the triangle error of calculation value that is included in the object, described error metrics is corresponding with the parameter of the influence degree of indicating each triangle of being included in the object that object is played up based on error metrics; Subside in proper order with definite triangle, early subsided so that have the triangle of less error amount.

Described method also can comprise: produce and to comprise and being used at the more new node of a plurality of leg-of-mutton information of subsiding gradually between the level that subsides; With the generation node, this node comprises about begin the information of the leg-of-mutton level that subsides from it in object.

Described method also can may further comprise the steps one of at least: produce the color node, in this node, be arranged with the colouring information on the colouring information that is included in the summit in the object and the summit that subsides, and producing the vertex color node that subsides, this vertex color node that subsides relates to the position of the colouring information that is arranged in the summit that subsides in the described color node; Produce the normal node, in this node, be arranged with the normal information and the normal information on summit of subsiding on the summit of object, and produce the vertex normal node that subsides, this vertex normal node that subsides relates to the position of the normal information that is arranged in the summit that subsides in the described normal node; With generation texture coordinate node, in this node, be arranged with the texture coordinate information and the texture coordinate information on summit of subsiding on the summit of object, and producing the vertex texture coordinate node that subsides, this vertex texture coordinate node that subsides relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

According to a further aspect in the invention, provide the method for a kind of establishment Virtual Reality Modeling Language (VRML) model, described VRML model is used for the graph data that comprises one or more leg-of-mutton objects is carried out adaptive transformation.This method comprises: determine the summit that subsides that triangle, the triangle that will be subsided in object subside order and will subside and create by diabolo; Produce the coordIndex node, in this node, about being included in leg-of-mutton information in the object by the triangle series arrangement of subsiding; Produce the IodSequence node, it comprises the triangle order information that subsides; Produce the coord node, in this node, be arranged with the coordinate information on summit of object and the coordinate information on the summit that subsides; With generation coordStart node, it relates to the position of the coordinate information that is arranged in the summit that subsides in the described coord node.

This method also can one of may further comprise the steps: produce the normalIndex node, in this node, the series arrangement of subsiding by diabolo about each the leg-of-mutton information that is included in the object, produce the normal node, in this node, be arranged with the normal information and the normal information on summit of subsiding on the summit of object, and produce the normalStart node, this node relates to the position of the normal information that is arranged in the summit that subsides in the described normal node; Produce the colorIndex node, in this node, the series arrangement of subsiding by diabolo is about being included in each the leg-of-mutton information in the object, produce the color node, in this node, be arranged with the colouring information and the colouring information on summit of subsiding on the summit of object, and produce the colorStart node, this node relates to the position of the colouring information that is arranged in the summit that subsides in the described color node; With generation texcoordIndex node, in this node, the series arrangement of subsiding by diabolo is about being included in each the leg-of-mutton information in the object, produce the texture coordinate node, in this node, be arranged with the texture coordinate information and the texture coordinate information on summit of subsiding on the summit of object, and produce the texcoordStart node, this node relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

According to a further aspect in the invention, provide a kind of conversion to comprise the equipment of the graph data of one or more leg-of-mutton objects.This equipment comprises: pretreatment unit, the summit that subsides of determining at least one triangle that will be subsided in the triangle in being included in object and determining to create by the triangle that subsides, and rendering unit, based on the graph data of object is carried out conversion and carrying out object and play up about the leg-of-mutton information determining by pretreatment unit to be subsided with about the information on the summit that subsides determined.

According to a further aspect in the invention, provide a kind of equipment that the graph data of object is carried out adaptive transformation.This equipment comprises: pretreatment unit, reception comprises about the information on the summit of object and comprises the graphical model of at least one leg-of-mutton object about at least one the leg-of-mutton information in the object of being included in expression, definite at least one triangle that will be subsided in the triangle in being included in object, determine to comprise about at least one leg-of-mutton information of determining to be subsided with about the graphical model of the information on the summit that subsides determined by the summit and creating of subsiding that at least one triangle that subsides is created; And rendering unit, carry out conversion and play up described object based on the graph data of the graphical model of creating described object.

According to a further aspect in the invention, provide a kind of equipment that the graph data that comprises one or more leg-of-mutton objects is carried out adaptive transformation.This equipment comprises: pretreatment unit, definition is included in the error metrics of the parameter of the influence degree that each triangle in the object plays up object as expression, and based on described error metrics to being included in each the triangle error of calculation value in the object; And rendering unit, the triangle that has minimum error values in the error amount of described calculating is at first subsided and plays up described object.

According to a further aspect in the invention, provide a kind of establishment to be used for the equipment of graphical model that conversion adaptively comprises the graph data of one or more leg-of-mutton objects, this equipment comprises: the error amount counter, determine that based on the influence degree that each triangle that is included in the object is played up object the triangle and the triangle that will be subsided subside in proper order in object; The summit counter that subsides is determined the summit that subsides that will create by the triangle that subsides; With the graphical model creator, produce triangle identifier node, in this node, about be included in the object triangle with triangle subside order be arranged, comprise triangle subside the LOD order node of order information, be included in the coordinate node that the coordinate information on the coordinate information on the summit in the object and the summit that subsides is arranged therein, and the vertex position node that subsides of position that relates to the coordinate information on the summit that subsides that is arranged in the coordinate node.

According to a further aspect in the invention, provide a kind of establishment to be used for the equipment of VRML model that conversion adaptively comprises the graph data of a plurality of leg-of-mutton objects, this equipment comprises: error amount counter, the influence degree of object being played up based on each triangle that is included in the object are determined the triangle that will be subsided and the triangle sequence of subsiding in object; The summit counter that subsides is determined the summit that subsides that will create by the triangle that subsides; With the graphical model creator, produce the colorIndex node, in this node, be arranged, comprise the subside lodsequence node of order information of triangle about the information that is included in the object with the triangle order of subsiding, be included in the coord node that the coordinate information on the summit in the object and the coordinate information on summit of subsiding are arranged therein, and the coordStart node that relates to the position of the coordinate information that is arranged in the summit that subsides in the coord summit.

According to a further aspect in the invention, provide at least a storage control to be used to carry out the computer-readable medium of instruction of at least one processor that the graph data that comprises at least one leg-of-mutton object is carried out the method for conversion, described method comprises: determine at least one triangle that will be subsided at least one triangle in being included in object; Determine the summit that subsides by at least one triangle is subsided and created; With based on coming the graph data of transforming object about at least one leg-of-mutton information of determining to be subsided with about the information on the summit that subsides determined.

According to a further aspect in the invention, provide at least a storage control to be used to carry out the computer-readable medium of instruction of at least one processor that graph data to object carries out the method for adaptive transformation, described method comprises: receive and comprise about the information on the summit in object and comprise the graphical model of at least one leg-of-mutton object about at least one the leg-of-mutton information in the object of being included in expression; Definite at least one triangle that will be subsided in the triangle in being included in object, and definite summit that subsides that subsides and create by diabolo; Establishment comprises about the leg-of-mutton information of determining to be subsided with about the graphical model of the information on the summit that subsides determined; With based on the graph data of the graphical model transforming object of creating and play up this object.

According to a further aspect in the invention, the computer-readable medium of at least a storage instruction is provided, at least one carries out the processor that the graph data that comprises at least one leg-of-mutton object is carried out the method for adaptive transformation described instruction control, described method comprises: definition is as the error metrics of designator, the effect that each triangle that comprises in this designator denoted object applies the expression of object; Based on error metrics for each triangle error of calculation value that comprises in the object; And the triangle that at first is collapsed upon the error amount that has minimum in the error amount that calculates.

According to a further aspect in the invention, the computer-readable medium of at least a storage instruction is provided, at least one carries out described instruction control in being expressed as the object that comprises one or more leg-of-mutton graph datas, triangle subsided is the processor of the method on summit, and described method comprises: to the lip-deep normal of each definition grid on leg-of-mutton three summits that will be subsided; To described leg-of-mutton each summit definition tangent plane, described tangent plane comprises described summit and perpendicular to the normal corresponding with described summit; The central point on described leg-of-mutton three summits is projected on three tangent planes to each definition on three summits, obtain the point of three projections thus; And the mean value of the point by calculating three projections obtains the summit that subsides.

According to a further aspect in the invention, the computer-readable medium of at least a storage instruction is provided, at least one carry out to create the processor of method that is used for the graph data that comprises one or more leg-of-mutton objects is carried out the graphical model of adaptive transformation described instruction control, and described method comprises: determine in the object subside order and will be by described at least one leg-of-mutton summit that subsides that subsides and create of at least one triangle, triangle that will be subsided; Be created in wherein the leg-of-mutton information that comprises about object with the triangle triangle identifier node that order arranges that subsides; Generation comprises the subside LOD order node of order information of triangle; Be created in the coordinate node that the coordinate information on the coordinate information on the summit that object wherein comprises and the summit that subsides is arranged; And producing the vertex position node that subsides, it relates to the position of the coordinate information on the summit that subsides that is arranged in the coordinate node.

According to a further aspect in the invention, the computer-readable medium of at least a storage instruction is provided, at least one carry out to create the processor of method that is used for the graph data that comprises one or more leg-of-mutton objects is carried out the VRML model of adaptive transformation described instruction control, and described method comprises: determine subside order and will be by described at least one leg-of-mutton summit that subsides that subsides and create of at least one triangle, the triangle that will be subsided in the object; Be created in wherein the leg-of-mutton information that comprises about object with the triangle coordIndex node that order arranges that subsides; Generation comprises the subside lodSequence node of order information of triangle; Be created in the coord node that the coordinate information of the coordinate information on the summit that object wherein comprises and the node that subsides is arranged; And producing the coordStart node, it relates to the position of the coordinate information on the summit that subsides of arranging in the coord node.

According to a further aspect in the invention, the method that provides a kind of conversion to comprise the graph data of a plurality of leg-of-mutton objects, described method comprises: definite at least one triangle that will be subsided in a plurality of triangles; Determining will be by the summit that subsides of described at least one triangle establishment of subsiding; And come the graph data of transforming object based on described at least one triangle determining to be subsided and the summit that subsides.

According to a further aspect in the invention, the computer-readable medium of at least a storage instruction is provided, at least one carries out the processor of method that conversion comprises the graph data of a plurality of leg-of-mutton objects described instruction control, and described method comprises: determine at least one triangle that will be subsided in a plurality of triangles; Determining will be by the summit that subsides of described at least one triangle establishment of subsiding; And come the graph data of transforming object based on described at least one triangle determining to be subsided and the summit that subsides.

Description of drawings

By the description of carrying out below in conjunction with accompanying drawing to exemplary embodiment, it is clear and easier to understand that these and/or others, characteristics and advantage of the present invention will become, wherein:

Figure 1A to Fig. 1 C is the diagrammatic sketch that is used to explain traditional level of detail (LOD);

Fig. 2 illustrates the notion of LOD according to an exemplary embodiment of the present invention;

Fig. 3 is the schematic block diagram that is used to realize the equipment of LOD according to an exemplary embodiment of the present invention;

Fig. 4 is the more detailed block diagram of pretreatment unit shown in Figure 3;

Fig. 5 is the process flow diagram of LOD rendering intent according to an exemplary embodiment of the present invention;

Fig. 6 is the schematic block diagram that is used for realizing with Virtual Reality Modeling Language (VRML) equipment of LOD method according to an exemplary embodiment of the present invention;

Fig. 7 is the detailed view of pretreatment unit shown in Figure 6;

Fig. 8 is the process flow diagram by the pretreatment operation of pretreatment unit execution shown in Figure 7;

Fig. 9 is the process flow diagram of being carried out by rendering unit shown in Figure 6 of playing up operation;

Figure 10 A to Figure 10 D illustrates the notion that is used for error of calculation tolerance according to an exemplary embodiment of the present;

Figure 11 illustrates according to an exemplary embodiment of the present and creates the notion on the summit that subsides by the single triangle that subsides;

Figure 12 is a process flow diagram of creating the process on the summit that subsides according to an exemplary embodiment of the present by the single triangle that subsides;

Figure 13 A to 13F illustrates the example of creating the process on the summit that subsides by the single triangle that subsides;

Figure 14 illustrates according to an exemplary embodiment of the present the method for the texture coordinate value on the summit that obtains to subside;

Figure 15 illustrates according to an exemplary embodiment of the present the method for the normal vector on the summit that obtains to subside;

Figure 16 illustrates according to an exemplary embodiment of the present the method for the color on the summit that obtains to subside;

Figure 17 is used to explain the diagrammatic sketch of seamless rendering according to an exemplary embodiment of the present invention;

Figure 18 is illustrated in the distance relation between the camera and three-dimensional (3D) grid in the seamless rendering of Figure 14;

Figure 19 A to 19C is illustrated in the progressive conversion between LOD level " k-1 " and the LOD level " k ";

Figure 20 A to 20C illustrates the example of geometry deformation (geomorphing) according to an exemplary embodiment of the present invention;

Figure 21 illustrates the node grammer in the LOD method according to an exemplary embodiment of the present invention;

Figure 22 is illustrated in the structure of the lodSequence that shows among Figure 21;

Figure 23 is the diagrammatic sketch that is used for explaining the updateDist that shows at Figure 21;

Figure 24 is the diagrammatic sketch that is used for explaining the minScreenArea that shows at Figure 21;

Figure 25 is used to explain original VRML model transferring the diagrammatic sketch that is the VRML model according to an exemplary embodiment of the present invention;

Figure 26 A illustrates the example that comprises at least two leg-of-mutton objects;

Figure 26 B illustrates the original VRML model that is used for the object shown in Figure 26 A; And

Figure 26 C illustrates the LOD VRML model that is used to play up the object shown in Figure 26 A according to an exemplary embodiment of the present invention.

Embodiment

Now will be in detail with reference to the exemplary embodiment of the present invention of its example shown in the drawings, wherein, identical label is represented identical parts all the time.Below exemplary embodiment is described to explain the present invention by the reference accompanying drawing.

Fig. 2 illustrates the notion of level of detail (LOD) according to an exemplary embodiment of the present invention.Primary object 210 comprises that 10 triangle T 1 are to T10.When the triangle T 1 to T4 of primary object 210 was subsided, the object of conversion comprised that 6 triangle T 5 are to T10.

In the present invention, in order to simplify the graph data that also conversion comprises leg-of-mutton object, single triangle is subsided to form the summit.With reference to Fig. 2, the triangle T 1 of primary object 210 has three summit V1, V2 and V3.When the triangle T 1 of primary object 210 is subsided, also subsided with triangle T 2, T3 and the T4 on two summits among triangle T 1 shared three summit V1, V2 and the V3.Therefore, when triangle T 1 was subsided, four triangle T 1 to T4 were subsided.Consequently, the object 220 that comprises the conversion of triangle T 5 to T10 is created.In other words, in the method for transforming object according to an exemplary embodiment of the present invention,, single triangle creates the summit that subsides by being subsided.The summit V4 of the object 220 of conversion is corresponding to the described summit that subsides.

Fig. 3 is the schematic block diagram that is used to realize the equipment 300 of LOD according to an exemplary embodiment of the present invention.Equipment 300 comprises pretreatment unit 310 and rendering unit 320.

Pretreatment unit 310 receives about the information with coloured object, and the information that is used for LOD is carried out pre-service, and will offer rendering unit 320 with the information that is used for LOD about the information of object.

The object of expressing with graph data comprises summit and triangle according to an exemplary embodiment of the present invention.The summit is the fundamental element of object, and each triangle, and promptly the surface of object is corresponding to three summits.Usually, can express the surface that constitutes object by various polygons, and polygon can be expressed with triangle.Therefore, the present invention with triangle as various polygonal examples.

Pretreatment unit 310 receives about the information (hereinafter being referred to as the object vertex information) with the summit of coloured object, and object triangle information representing and attribute information are as selective information; The leg-of-mutton order of determining in object, will to be subsided (hereinafter be referred to as triangle subside order); And calculate be used for LOD pass through the subside attribute information on the subside summit and the summit that subsides of creating of diabolo.In other words, pretreatment unit 310 offers rendering unit 320 with subside order information and the vertex attribute information of subsiding of object vertex information, the vertex information of subsiding, object triangle information representing, triangle.

Rendering unit 320 receives about with the information of coloured object and the information that is used for LOD from pretreatment unit 310, and simultaneously based on the information conversion object that is used for LOD, and rendering objects, thereby output is with the graph data that is shown.

Fig. 4 is the detailed diagram of the pretreatment unit 310 shown in Fig. 3.With reference to Fig. 4, pretreatment unit 310 comprises error amount counter 311, subside the summit counter 312 and the vertex attribute information calculator 313 of subsiding.

Error amount counter 311 is based on error metrics each triangle error of calculation value to object.Error metrics is represented the influence degree that triangle is played up object, and is used to find out the triangle of object being played up in the little object of influence removing leg-of-mutton the time.Owing to preferably subside, so determine that by when removing it, object being played up the little leg-of-mutton mode of influence error metrics is important to when removing it, object being played up the little triangle of influence.To describe the scheme of determining error metrics after a while in detail.

The triangle that has least error in the error amount that each triangle that is included in by 311 pairs of error amount counters in the object calculates has the highest priority of subsiding.In other words, the ascending order by error amount sorts to the triangle that will be subsided.Rendering unit 320 (Fig. 3) is according to the triangle of determining during LOD the handles order triangle that subsides that subsides.

The leg-of-mutton information that the summit counter 312 that subsides receives about being subsided from error amount counter 311, and use from information, object vertex information and the object triangle information representing of 311 receptions of error amount counter and calculate the summit that subsides.In other words, when the triangle that will be subsided is determined, the summit counter 312 of subsiding uses the vertex of a triangle information that will be subsided and object triangle information representing to calculate the summit that subsides that will subside and create by diabolo, and the vertex information of will subsiding outputs to rendering unit 320.To describe the scheme of calculating the summit that subsides after a while in detail.

The vertex attribute information calculator 313 of subsiding receives leg-of-mutton information about being subsided from error amount counter 311, and uses the information that receives from error amount counter 311 and calculate the vertex attribute information of subsiding about the attribute information on the summit of object.Can differently calculate the vertex attribute information of subsiding according to its feature, maybe can use the mean value on the summit that will be subsided to calculate the vertex attribute information of subsiding to simplify calculating.

Rendering unit 320 is subsided and is created the summit that subsides and carry out LOD by subside vertex information and the vertex attribute information diabolo that subsides of use, thereby can simplify the graph data of object.

Fig. 5 is the process flow diagram of LOD rendering intent according to an exemplary embodiment of the present invention.In operation 510, pretreatment unit 310 receives the information (being the object vertex information) and the object triangle information representing that will experience the summit in the object that LOD plays up about being included in.In operation 520, pretreatment unit 310 use error measure each the triangle error of calculation value to object.In operation 530, pretreatment unit determines that based on the error amount that each triangle in object is calculated triangle subsides in proper order.In operation 540, pretreatment unit calculates the summit that subsides that will subside and be created by diabolo.In operation 550, rendering unit is based on object vertex information, object triangle information representing, triangle the subside order information and the vertex information rendering objects when carrying out LOD and handling of subsiding.

Fig. 6 is the schematic block diagram that is used for realizing with Virtual Reality Modeling Language (VRML) equipment 600 of LOD method according to an exemplary embodiment of the present invention.With reference to Fig. 6, equipment 600 comprises pretreatment unit 610 and rendering unit 620.

According to an exemplary embodiment of the present, pretreatment unit 610 receives the input VRML model that is used for coloured object, and execution is used for the pre-service of LOD processing with establishment LOD VRML model, and LOD VRML model is offered rendering unit 620.

Be used for the input VRML model of coloured object is comprised: " coord ", it comprises the coordinate information that is included in the summit in the object; And " coordIndex ", it comprises about the surface, the leg-of-mutton information that is promptly formed by the connection on summit.In addition, input VRML model also optionally comprises the attribute information such as " normal ", " normalIndex ", " color ", " colorIndex ", " texcoord " and " texcoordIndex "." normal " refers to the normal value on summit, " normalIndex " refers to the surface that is formed by the summit with described normal value, " color " refers to the color value on summit, " colorIndex " refers to the surface that is formed by the summit with described color value, the texture coordinate value that " texcoord " refers to the summit, and " texcoordIndex " refers to the surface that is formed by the summit with described texture coordinate value.

Pretreatment unit 610 determines that based on " coord " and " coordIndex " triangle in the object subsides in proper order, and generates the lodSequence node.In addition, pretreatment unit 610 calculates the summit that subsides that subsides and create by diabolo, and produces the coordStart node of the positional information with the described summit that subsides.When attribute information exists, pretreatment unit 610 calculates the normal value on the summit that subsides based on " normal " and " normalIndex ", calculate the color value on the summit that subsides based on " color " and " colorIndex ", and calculate the texture coordinate value on the summit that subsides based on " texcoord " and " texcoordIndex ".In addition, pretreatment unit 610 produces the normalStart node, colorStart node, and texcoordStart node, and they have the correlation attribute information on the summit that subsides.Primitive color information can be kept, and the color value on the summit that subsides need not be calculated and produce again about leg-of-mutton three summits that subside.In the case, will not produce the colorStart node.

In addition, in order to reduce uncomfortable sensation owing to the leg-of-mutton beholder that causes of subsiding, pretreatment unit 610 is determined the level that diabolo subsides and will begin in primary object, to produce the minScreenArea node, and the updateDist node of the effect between the level of described level and back produce to be described, subside with diabolo little by little.Pretreatment unit 610 will comprise that the LOD VRML model of the node of generation offers rendering unit 620.

Rendering unit 620 receives LOD VRML models from pretreatment unit 610, and in transforming object rendering objects, thereby output is with the graph data that is shown.

Fig. 7 is the detailed view of the pretreatment unit 610 shown in Fig. 6.With reference to Fig. 7, pretreatment unit 610 comprises error amount counter 611, the summit counter 612 that subsides, the vertex attribute information calculator 613 of subsiding and LOD VRML model creation device 614.

Error amount counter 611 is based on error metrics each triangle error of calculation value to object.Have the triangle that in the error amount that calculates by error amount counter 611, has minimum error values and have the highest priority of subsiding.In other words, the triangle that will be subsided is sorted according to the ascending order of their error amount.To subside about the triangle of determining the as mentioned above information of order of error amount counter 611, promptly the triangle order information that subsides offers subside summit counter 612 and LOD VRML model creation device 614.

The leg-of-mutton information that the summit counter 612 that subsides receives about being subsided from error amount counter 611, and use from information, the object vertex information of 611 receptions of error amount counter, i.e. " coord " and object triangle information representing, promptly " coordIndex " calculates the summit that subsides.The summit counter 612 that subsides will offer subside vertex attribute information calculator 613 and LODVRML model creation device 614 by calculating the vertex information of subsiding that obtains.

The leg-of-mutton information that the vertex attribute information calculator 613 of subsiding receives about being subsided from error amount counter 611, and use from the information of error amount counter 611 receptions and about being included in the attribute information on the summit the object, promptly " normal ", " nomalIndex ", " color ", " colorIndex ", " texcoord ", " texcoordIndex " wait the vertex attribute information of subsiding of calculating.The vertex attribute information calculator 613 of subsiding will offer LOD VRML model creation device 614 by calculating the vertex attribute information of subsiding that obtains.

LOD VRML model creation device 614 receives " coord ", " coordIndex ", the vertex information of subsiding, the vertex attribute information of subsiding and the triangle order information that subsides, the vertex information of will subsiding is inserted " coord " to produce the coord node of conversion, the normal information on summit of will subsiding is inserted " normal " to produce normal node of conversion, the colouring information on summit of will subsiding inserts " color " producing color node of conversion, and the texcoord information on the summit that will subside is inserted " texcoord " to produce texcoord node of conversion.Can use primitive color information, and not produce the color node of the conversion of the colouring information that comprises the summit that subsides about leg-of-mutton three summits that will be subsided.In the case, with the color node that produces from wherein being removed about the leg-of-mutton primitive color information that will be subsided.

In addition, LOD VRML model creation device 614 produce the position on the summit that subsides that relates to insertion " coord " the coordStart node, relate to insertion " normal " the vertex attribute that subsides the position the normalStart node, relate to insertion " color " the vertex attribute that subsides the position the colorStart node, relate to the texcoordStart node of position of the vertex attribute that subsides of insertion " texcoord ".Should be appreciated that, be optional such as the attribute information of " normal ", " color " and " texcoord ".

In addition, under the situation of the color that does not produce the summit that subsides again, do not produce the colorStart node.

And, LOD VRML model creation device 614 uses the triangles order information that subsides to produce the coordIndex of conversion according to the triangle that triangle subsides in the series arrangement " coordIndex ", the triangle that subsides in the series arrangement " normalIndex " according to triangle produces the normalIndex of conversion, the triangle that subsides in the series arrangement " colorIndex " according to triangle produces the colorIndex of conversion, and the triangle that subsides in the series arrangement " texcoordIndex " according to triangle produces the texcoordIndex of conversion.LOD VRML model creation device 614 also produces and relates to the subside IodSequence node of order information of triangle, and produces updateDist node and minScreenArea node according to predetermined configuration information in user's input or the system.LOD VRML model creation device 614 outputs to rendering unit 620 with the LODVRML model, and described LOD VRML model comprises coord node, coordIndex node, IodSequence node, coordStart node, updateDist node and minScreenArea node.When also having attribute information, in LOD VRML model, also can comprise: normal node, normalIndex node, normalStart node, color node, colorIndex node, colorStart node, texcoord node, texcoordIndex node, texcoordStart node etc.

Fig. 8 is the process flow diagram by the pretreatment operation of pretreatment unit 610 execution that show among Fig. 7.

In operation 810, pretreatment unit 610 receives about will be according to information " coord " and " coordIndex " of the coloured object of VRML model, and the use error metric calculation is included in each the leg-of-mutton error amount in the object.In operation 820, pretreatment unit 610 calculates the summit that subsides to each triangle.In operation 830, pretreatment unit 610 is arranged the triangle that is included among the coordIndex by the ascending order of error amount.In operation 840, pretreatment unit 610 produces IodSequence and coordStart based on the coordIndex that arranges.In operation 850, pretreatment unit 610 is provided with the value of minScreenArea and the value of updateDist according to user's input or the predetermined value of setting.In operation 860, pretreatment unit 610 is stored in coord, coordIndex, IodSequence, coordStart, updateDist and minScreenArea in the LOD VRML model.

Fig. 9 is the process flow diagram of being carried out by the rendering unit 620 that shows among Fig. 6 of playing up operation.

With reference to Fig. 9, in operation 910, rendering unit 620 receives the LOD VRML model that is produced by pretreatment unit 610 (Fig. 6 and 7).In operation 920, rendering unit 620 is determined the LOD starting point based on minScreenArea.In operation 930, rendering unit 620 is carried out the LOD processing based on IodSequence and coordStart.In operation 940, rendering unit 620 is carried out geometry deformation according to updateDist.

Describe LOD method according to an exemplary embodiment of the present invention below in detail.

Error metrics

To describe below according to an exemplary embodiment of the present invention as the error metrics that is used for definite leg-of-mutton designator that will be subsided.

As mentioned above, the leg-of-mutton effect in the error metrics denoted object.The result who obtains error metrics for each triangle F of object is the error value E (F) of triangle F.When triangle had maximum E (F), it had brought into play the highest influence to object.Therefore, preferably has last triangle that the triangle of maximum E (F) is subsided.Owing to have the triangle of minimum E (F) object has been brought into play minimum influence, so first triangle that this triangle can be confirmed as being subsided.

Error metrics E (F) can be defined by equation 1:

E(F)＝E _geometry(F)+E _attribute(F) (1)

Whole error E (F) can be represented as the error E about geometric properties _Geometry(F) with about the error E of attributive character _Attribute(F) and.

For error E _Geometry(F), can increase visual quality by at first removing the interior triangle have than littler curvature of other triangle and littler area.Therefore, error E _Geometry(F) can define by equation 2:

$E_{\mathrm{geometry}}\left(F\right)=$

Wherein, " curvature (F) " is leg-of-mutton curvature, i.e. radius-of-curvature, and can be used as 1/ (approaching the radius of F and adjacent leg-of-mutton spheroid most) and obtained, " F " indication will obtain the target triangle of error metrics, Nei _FIndicate the leg-of-mutton quantity adjacent with the target triangle.In other words, curvature (F) is the radius-of-curvature of spheroid, and this spheroid can be formed the face that is formed by target triangle and adjacent triangle thereof to approach most.

In addition, the influence degree of " area (F)/area (in the grid maximum triangle) " leg-of-mutton area of indicating target, and be the ratio of the leg-of-mutton area of target and the leg-of-mutton area of maximum in the object.

" | Nei _F＜3| " whether the indicating target triangle be positioned at the border.Because Nei _FBe the leg-of-mutton quantity adjacent, so determine that whether adjacent leg-of-mutton quantity is less than 3 with target triangle F.For example, the target triangle F that shows in Figure 10 A has three neighbours, but the target triangle F that shows among Figure 10 B has two neighbours.Triangle F with three neighbours shown in Figure 10 A subsided compare with the triangle F with two neighbours shown in Figure 10 B is subsided, object is played up brought into play littler influence.Therefore, | Nei _F＜3| is used to discern the leg-of-mutton designator that is positioned at the border and should not be subsided.

For error E _Attribute(F), can have the triangle that less color change and normal and texture coordinate value have less change between the adjacent triangle, increase visual quality by at first removing to compare with other triangle.Therefore, error E _Attribute(F) by equation 3 definition:

$E_{\mathrm{attribute}}\left(F\right)=d\·\mathrm{IsFaceSharp}+e\underset{i=0}{\overset{\left|{\mathrm{Nei}}_F\right|-1}{\mathrm{\Σ}}}\mathrm{CA}(F,{\mathrm{Nei}}_F\left(i\right))+f\underset{i=0}{\overset{\left|{\mathrm{Nei}}_F\right|-1}{\mathrm{\Σ}}}\mathrm{NA}(F,{\mathrm{Nei}}_F\left(i\right))---\left(3\right)$

Wherein, Nei _F(i) be the neighbours' of face " i " quantity, " CA (F, G)=| C _F(V ₁)-C _G(V ₁) |+| C _F(V ₂)-C _G(V ₂) | " the indication change color, " TA (F, G)=| T _F(V ₁)-T _G(V ₁) |+| T _F(V ₂)-T _G(V ₂) | " variation of indication texture coordinate value, " NA (F, G)=| N _F(V ₁)-N _G(V ₁) |+| N _F(V ₂)-N _G(V ₂) | " indication normal variation.With reference to Figure 10 C, " F " indication obtains the target triangle of error metrics, one of triangle that " G " indication is adjacent with target triangle F, V ₁And V ₂Indication is by target triangle F and the shared summit of adjacent triangle G.Here, IsFaceSharp (F) be used to handle by two or more triangles shared summit have the situation of different texture coordinate values.In detail, when different texture coordinate values was given single summit, the value that this summit is defined as " sharp " and IsFaceSharp (F) was " 1 ".On the other hand, when single texture coordinate was given this summit, the value of IsFaceSharp (F) was " 0 ".With reference to Figure 10 D, when having different texture coordinate values by four shared summit F0 of triangle F1, F2, F3 and F4, summit F0 is defined as " sharp ".Otherwise summit F0 is not defined as " sharp ".

Change color is by the summit V of target triangle F ₁Color value and the summit V of adjacent triangle G ₁Color value between difference and the summit V of target triangle F ₂Color value and the summit V of adjacent triangle G ₂Color value between difference and define.

The variation of normal is by the summit V of target triangle F ₁Normal value and the summit V of adjacent triangle G ₁Normal value between difference and the summit V of target triangle F ₂Normal value and the summit V of adjacent triangle G ₂Normal value between difference and define.

The coefficient that occurs in equation 2 and 3 is described below.The default value of each coefficient is selected by this way, comprises that promptly the item of coefficient has value between 0 and 1.Coefficient " a " is defined in the radius-of-curvature that has the ball of minimum profile curvature radius among all triangles of object.Therefore, " a*curvature (F) " has the value between 0 and 1.Coefficient " b " is defined as " 1 ".Therefore, the item that comprises coefficient " b " has value between 0 and 1.The item that comprises coefficient " c " is used to not this specific purposes of subsiding of the triangle on the border.Therefore, coefficient " c " the big default value that is defined as being scheduled to.

Coefficient " d " is used to prevent that the triangle that is mapped to different texture from being subsided, therefore, and the default value that coefficient " d " is defined as being scheduled to.Because leg-of-mutton the subsiding that is mapped to different texture provides littler visible change with subsiding to compare at border leg-of-mutton, so coefficient " d " has than the littler value of coefficient " c ".For example, when coefficient " c " value of being set to 100, coefficient " d " can the value of being set to 10.

Coefficient " e " and " f " can by as give a definition:

$e=\frac{1}{3\max \left(\mathrm{CA}\right)}=\frac{1}{6\sqrt{{(R_1-R_2)}^2+{(G_1-G_2)}^2+{(B_1-B_2)}^2}}$

$=\frac{1}{6\sqrt{{(1-0)}^2+{(1-0)}^2+{(1-0)}^2}}=\frac{1}{6\sqrt{3}}$

$f=\frac{1}{3\max \left(\mathrm{NA}\right)}=\frac{1}{3*2*2}=\frac{1}{12}.$

To wanting all triangles in the coloured object to use aforementioned calculation to obtain error metrics, i.e. error amount.Based on error amount, can determine which triangle is subsided early than other triangle when object is transformed.In detail, the triangle with minimum error values is confirmed as first triangle that will be subsided, and the triangle with second little error amount is confirmed as second triangle that will be subsided.In pretreatment operation, the error amount that use to calculate wants the triangle of coloured object to arrange by the ascending order of their error amount, and about the information that puts in order, promptly the triangle order information that subsides is provided for and plays up operation.Subsequently, in playing up operation, based on the triangle order information that subsides, during LOD handled, triangle subsided and is performed.

The subside calculating on summit

The triangle that will be subsided in based on error metrics result calculated rendering objects or definite triangle calculate the summit that subsides that will be created after subsiding in proper order when triangle is subsided.Be preferably in the object by the triangle new summit that subsides of creating that subsides and change the original-shape of object as small as possible.

Figure 11 illustrates according to an exemplary embodiment of the present invention and creates the notion on the summit that subsides by single triangle is subsided.With reference to Figure 11, the xsect of the object before label 1100 expression triangles subside, the xsect of the object after label 1110 expression triangles subside.

Before triangle subsided, xsect 1100 comprised summit M1, M2, M3 and M4.Preferably subsided with the establishment summit that subsides, so that the original-shape G of object changes as small as possible by the triangle of summit M2 and M3 (because Figure 11 is a viewgraph of cross-section, leg-of-mutton another summit does not show) definition.Yet, can't know the original-shape G of object.Therefore, shape and the akin summit M5 that subsides of original-shape G that selects object is transformed is very important.

Figure 12 is the process flow diagram of the process of creating the summit that subsides by single triangle is subsided according to an exemplary embodiment of the present invention.In operation 1210, vertex of a triangle V1, V2 and the V3 that be subsided are defined, and each summit V1, V2 and V3 normal N 1, N2 and the N3 on surface mesh is defined.In operation 1220, comprise that summit Vi and the plane vertical with normal N i are defined as tangent plane P1, P2 and P3.In operation 1230, the leg-of-mutton central point that be subsided, promptly C=(V1+V2+V3)/3 is obtained.In operation 1240,, obtain three subpoint C1, C2 and C3 by described leg-of-mutton central point C is projected on independent tangent plane P1, the P2 and P3.In operation 1250, by the leg-of-mutton point that subsides and create, the summit V4 that promptly subsides is calculated as (C1+C2+C3)/3, that is, and and the mean value of three subpoint C1, C2 and C3.The attribute of summit V4 of subsiding is determined by the mean value of the attribute of tangent plane P1, P2 and P3.

The example of the process of creating the summit that subsides by single triangle is subsided is according to an exemplary embodiment of the present invention described with reference to Figure 13 A to 13F below.

With reference to Figure 13 A, object 1300 comprises four triangle T 1, T3, T7 and T8.Triangle T 1 has summit V1, V2 and V3.Suppose that triangle T 1 must be subsided.Fig. 2 shows the primary object 210 when observing triangle T 1 from the top, and Figure 13 A shows the object 1300 when observing the triangle T 1 of primary object 210 from the side, to help to explain the object in three-dimensional (3D) view.

With reference to Figure 13 B, summit V1, the V2 of the triangle T 1 that will be subsided on the surface of grid 1300 and the normal of V3 are respectively defined as N1, N2 and N3.

With reference to Figure 13 C, comprise that summit Vi and the plane vertical with normal N i are defined as tangent plane Pi.In other words, comprise that summit V1 and the plane vertical with normal N 1 are defined as tangent plane P1.Comprise that summit V2 and the plane vertical with normal N 2 are defined as tangent plane P2.Comprise that summit V3 and the plane vertical with normal N 3 are defined as tangent plane P3.

With reference to Figure 13 D, the central point of the triangle T 1 that will be subsided is defined as C=(V1+V2+V3)/3.Central point C is projected to tangent plane P1, P2 and P3, obtain three subpoint C1, C2 and C3 thus.

With reference to Figure 13 E, calculate the point of being created by the triangle T 1 of subsiding, the summit V4 that promptly subsides is as the mean value of three subpoint C1, C2 and C3, i.e. (C1+C2+C3)/3.

Therefore, as Figure 13 F object of the conversion that comprises the summit V4 that subsides that is created by the triangle T 1 of subsiding that draws.

The attribute on summit of subsiding can be defined as the mean value to three defined property values of subpoint.Perhaps, can obtain by the feature on leg-of-mutton each summit of considering to be subsided the to subside more accurate attribute on summit.Below, will feature according to leg-of-mutton each summit that will be subsided obtain the to subside method of attribute on summit be described.The attribute on summit of subsiding can comprise texture coordinate value, color and normal vector.

The texture coordinate value on the following summit that obtains to subside.The texture coordinate value on summit of subsiding can be obtained to be subjected to most by the influence of the texture coordinate value on the summit on the most close summit that subsides in leg-of-mutton three summits that subside.

With reference to Figure 14, P1, P2 and P3 indicate the coordinate figure on leg-of-mutton three summits; The texture coordinate value of each of T1, T2 and three summits of T3 indication; P indicates the coordinate figure on the summit that subsides; The texture coordinate value on the described summit that subsides of T indication.When P than P1 or P2 apart from the distance of P3 when nearer, T is that influenced by T3 than T1 or T2 bigger.Here, can represent P by equation P=a1*P1+a2*P2+a3*P3.When using the a1, the a2 that obtain from described equation and a3, T can be represented as T=a1*T1+a2*T2+a3*T3.Yet, owing to P is not present on the plane that is formed by P1, P2 and P3, so can obtain Q on the triangle by P is projected to.Q can represent by equation Q=a1*P1+a2*P2+a3*P3.Coefficient a1, a2 and a3 are called as the barycentric coordinates of Q, and by equation $\frac{a1}{S_{P_2{\mathrm{QP}}_3}}=\frac{a2}{S_{P_1{\mathrm{QP}}_3}}=\frac{a3}{S_{P_1{\mathrm{QP}}_2}}$ Definition, wherein a1+a2+a3=1.Here, the SABC indication has the leg-of-mutton area of summit A, B and C.Coefficient a1, a2 and a3 can be redefined as follows:

${\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">b</figure-callout>}}_1={\mathrm{<figure-callout\; id="2"\; label="S\; P"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">S</figure-callout>}}_{P_{}}$

${\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">b</figure-callout>}}_2={\mathrm{<figure-callout\; id="1"\; label="S\; P"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">S</figure-callout>}}_{P_{}}$

${\mathrm{<figure-callout\; id="3"\; label="b"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">b</figure-callout>}}_3={\mathrm{<figure-callout\; id="1"\; label="S\; P"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">S</figure-callout>}}_{P_{}}$

b＝b ₁+b ₂+b ₃

$a_1=\frac{b_1}{b},$ $a_2=\frac{b_2}{b},$ $a_3=\frac{b_3}{b}.$

Therefore, use coefficient a1, the a2 and the a3 that obtain by above-mentioned equation can obtain texture coordinate value T=a1*T1+a2*T2+a3*T3.

The normal vector on summit below can obtain to subside.In spherical coordinate system, the normal vector on the summit that subsides can be obtained to be subjected to most the influence with the normal vector on the summit on the most approaching summit that subsides in quilt leg-of-mutton three summits that subside.

In spherical coordinate system, normal vector is positioned at the surface of the ball with radius 1.According to these characteristics, in spherical coordinate system, can represent the normal vector on leg-of-mutton three summits as shown in figure 15; And n1, n2 and n3 are meant the normal vector on leg-of-mutton three summits that will be subsided of representing in spherical coordinate system, and " n " is meant the normal vector on the summit of representing that subsides in spherical coordinate system:

n1＝(1，theta1，phi1)

n2＝(1，theta2，phi2)

n3＝(1，theta3，phi3)

n(1，theta，phi)。

Therefore, in spherical coordinate system by inserting (theta, phi) can obtain the to subside normal vector on summit.Here, new normal vector " n " is represented as n=a*n1+b*n2+c*n3, wherein a+b+c=1.Use the barycentric coordinates of when obtaining texture coordinate, using to represent coefficient " a ", " b " and " c ".

Thereafter, by will (1, theta phi) converts (x, y, z) can obtain the to subside normal vector on summit in the xyz coordinate system.

The color on summit below can obtain to subside.With reference to Figure 16, when the triangle with summit 2,4 and 5 is subsided for new summit 9, if color on every side is mixed, the then color on summit 9 and on every side TOTAL DIFFERENT COLOR.Therefore, after subsiding, can keep the primitive color of three summits 2,4 and 5, rather than new summit 9 is produced new color.In other words, new summit 9 has leg-of-mutton each three summits 2,4 that subside and 5 primitive color, that is, only be that the leg-of-mutton color of subsiding is removed.For example, when summit 2,4 and 5 when being respectively red, green and blue, red, green and blueness can be assigned to the summit 9 that subsides.As a result, even subsided when having the new triangle of summit 1,9 and 7 when the triangle with summit 1,4 and 7, this new triangle (1,9,7) has the color of original triangle (1,4,7).

For example, but below model of creation:

Original coordIndex[

2，1，7，-1，

0，1，5，-1，

0，4，2，-1，

2，3，1，-1，

0，5，4，-1，

1，3，5，-1，

2，4，3，-1，

4，5，3，-1，

0，7，1，-1，

6，0，2，-1，

6，2，7，-1，

6，7，0，-1]。

Original coordIndex[

c1，c2，c3，-1，

c4，c5，c6，-1，

c7，c8，c9，-1，

c10，c11，c12，-1，

c13，c14，c15，-1，

c16，c17，c18，-1，

c19，c20，c21，-1，

c22，c23，c24，-1，

c25，c26，c27，-1，

c28，c29，c30，-1，

c31，c32，c33，-1，

c34，c35，c36，-1]。

When in above-mentioned model, when triangle (6,7,0) was subsided for new summit 8, coordIndex was assigned with as follows:

New coordIndex[

2，1，8，-1，

8，1，5，-1，

8，4，2，-1，

2，3，1，-1，

8，5，4，-1，

1，3，5，-1，

2，4，3，-1，

4，5，3，-1]。

From new coordIndex can infer triangle (6,0,7) and with triangle (6,0,7) triangle (6,2 on shared two summits, 7), (6,0,2) and (0,7,1) be removed, and about with triangle (6,0,7) triangle on shared single summit, described single shared summit has been changed and has been new summit 8.In other words, triangle (2,1,7) is changed and is triangle (2,1,8); Triangle (0,1,5) is changed and is triangle (8,1,5); Triangle (0,4,2) is changed and is triangle (8,4,2); Triangle (0,5,4) is changed and is triangle (8,5,4).

New colorIndex[

c1，c2，c3，-1，

c4，c5，c6，-1，

c7，c8，c9，-1，

c10，c11，c12，-1，

c13，c14，c15，-1，

c16，c17，c18，-1，

c19，c20，c21，-1，

c22，c23，c24，-1]。

According to described new colorIndex, be removed from four color values of the bottom of original colorIndex, even and when the coordinate of vertex of a triangle was changed, the color on summit also was held.For example, (2,1,7) in original coordIndex are changed and are (2,1,8) in new coordIndex, but in original colorIndex (c1, c2 c3) remain unchanged in new colorIndex.

LOD level and geometry deformation

Figure 17 is the diagrammatic sketch that is used to explain according to the seamless rendering of exemplary embodiment of the present invention.With reference to Figure 17, when LOD level=0, original image 1710 is played up and without any conversion.When the LOD level after LOD level 0=1, played up by the object 1720 of the formed phase one conversion of a series of triangles that subside.LOD level=2 and LOD level=3 and produce the transforming object 1730 of subordinate phase and the transforming object of phase III 1740 respectively as rendering result respectively after LOD level 1 and LOD level 2.

Figure 18 illustrates camera and uses screen and the formed 3D distance between objects relation of grid.As " q " during less than predetermined threshold, that is, when The simplification process is performed.Here, " q " projects to the area of the 3D object on the screen and the ratio of the area of whole screens.When ratio " q " during less than predetermined threshold, the simplification or the conversion of 3D object begin.

LOD level " I " is directly proportional with distance " z " between camera and the grid.In other words, determine LOD level " I " with the logarithm scale according to distance " z ", as follows:

$I={\log }_2\left(\max (\frac{z^2}{{\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">z</figure-callout>}}_0^2},1)\right)$

${\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">z</figure-callout>}}_0^2=\frac{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="A200610003311.900571.png,A200610003311.900621.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}{{\mathrm{qp}}_x{p}_y}$

Wherein, p _xAnd p _yBe the camera projection coefficient, " r " is the radius of 3D object.

Figure 19 A is formed for explaining diagrammatic sketch according to geometry deformation of the present invention to Figure 19 C.When the LOD level changes, for example, when in primary object, when the quantity on leg-of-mutton quantity or summit reduces rapidly, explosion effect (poping effect) and bad effect appear visually.In order to prevent the explosion effect, the stage (a) (Figure 19 A) with level " k-1 " does not directly proceed to the stage (c) (Figure 19 C) with level " k ", but the interstage (b) (Figure 19 B) is inserted into.Because when the triangle in the object between exemplary embodiment pre-treatment period according to the present invention is subsided, the summit that subsides is calculated, so about the leg-of-mutton information that will be subsided with about can be obtained by the both information on the leg-of-mutton summit that subsides of being created of subsiding.

Therefore, only can easily during playing up, realize the interstage (b) (Figure 19 B) by the value of adjusting two information.

Figure 20 A to Figure 20 C illustrates the example of geometry deformation according to an exemplary embodiment of the present invention.When the stage (a) (Figure 20 A) proceeded to the stage (c) (Figure 20 C) via the interstage (b) (Figure 20 B), (c) (Figure 20 C) compared directly to enter the stage with the stage (a) (Figure 20 A), and object is by conversion more smoothly.

VRML node grammer

With regard to using the VRML browser, the input grid that is used for shortcut calculation is IndexedFaceSet, and its output is improved IndexedFaceSetLOD and simplification order.When original IndexedFaceSet was modified, new summit was introduced into.In other words, leg-of-mutton subsiding causes the establishment on new summit.As original IndexedFaceSet when being best, the element in coordIndex, normalIndex, colorIndex and texcoordIndex need be rearranged.The basic imagination that rearranges is that the information about the face that at first subsides is positioned at last position.

Figure 21 illustrates according to an exemplary embodiment of the present invention the node grammer according to LOD method redetermination.

The lodSequence node has the leg-of-mutton information about being subsided.The coordStart node has the positional information that comprises the leg-of-mutton coordinate information that will be subsided.The texcoordStart node has the positional information that comprises the leg-of-mutton texture coordinate information of will be subsided.The normalStart node has the positional information that comprises the leg-of-mutton normal information of will be subsided.The colorStart node has the positional information that comprises the leg-of-mutton colouring information that will be subsided.

Because coordinate must be present in the leg-of-mutton attribute information, so the coordStart node exists certainly.On the other hand, the attribute such as texture coordinate value, normal and color is that optionally therefore, texcoordStart, normalStart and colorStart are optional nodes.When being subsided, obtain by first leg-of-mutton first coordinate information that subsides the summit that subsides and create from coordStart, and obtain second coordinate information that subsides the summit from " coordStart+1 " more than a triangle.Also use this scheme for texcoordStart, normalStart and colorStart.The updateDist node definition is used for the one or more stages between two LOD levels of insertion of seamless rendering.MinScreenArea relates to the node of the starting point of LOD processing.

Simultaneously, in the node that in the VRML model, comprises, according to the present invention, coord node, texcoord node, normal node, color node, coordIndex node, texcoordIndex node, normalIndex node, colorIndex node are rearranged.

According to the present invention, the coord node has according to the definition of the VRML model original coordinates information with the summit of coloured object, and has the coordinate information on the summit that subsides of creating by the triangle that is collapsed upon the position after the original coordinates information.According to the present invention, the texcoord node has according to the definition of the VRML model original texture coordinate information with the summit in the coloured object, and has the texture coordinate information on the summit that subsides of creating by the triangle that is collapsed upon the position after the original texture coordinate information.According to the present invention, the normal node has according to the definition of the VRML model original normal information with the summit of coloured object, and has the normal information on the summit that subsides of creating by the triangle that is collapsed upon the position after the original normal information.The color node has according to the definition of the VRML model primitive color information with the summit of coloured object.When mean value used according to the invention obtained to subside the color on summit, the colouring information on the summit that subsides of creating by the triangle that subsides was located in after the primitive color information.Alternatively, when the primitive color information of the vertex of a triangle that will be subsided was used to subside the color on summit under the situation of not using mean value, the leg-of-mutton colouring information that only subsides was by from the color knot-removal.

The order of being subsided with triangle rearranges the element in coordIndex node, texcoordIndex node, normalIndex node and the colorIndex node.

Simplification is encoded into the MFInt32 lodSequence with form shown in Figure 22 in proper order.The grid indication of LOD=0 is being transformed, that is, and and the state of the primary object before simplifying.With reference to Figure 22, when producing the grid of LOD=1, n ₁Individual triangle is subsided.In Figure 22, " 1 " between the grid of LOD=1 and the grid of LOD=2 is separator.When producing the grid of LOD=2, n ₂Individual triangle is subsided.When producing the grid of LOD=N, n _NIndividual triangle is subsided.

Although do not describe, here with the identical mode of coordIndex node is removed texcoordIndex node, normalIndex node and colorIndex node execution face.

Figure 23 is the diagrammatic sketch that is used to explain updateDist shown in Figure 21.UpdateDist is used to be provided with less important level with the node of transforming object little by little between the LOD of LOD level and back level.

Figure 24 is the diagrammatic sketch that is used to explain minScreenArea shown in Figure 21.As mentioned above, determine minScreenArea in the ratio of the grid of playing up in whole screen.MinScreenArea is the node of the starting point of definition LOD processing.

Figure 25 is illustrated in single triangle 2530 to be subsided and produce under the exemplary cases on the single summit 2540 that subsides, and according to an exemplary embodiment of the present original VRML model 2510 is transformed into the diagrammatic sketch of the process of LODVRML model 2520.

With reference to Figure 25, original VRML model 2510 comprises the summit 0,1 that comprises about object 2530 and 2 information, that is, coord node 2511, about the information of the face of object 2530, that is, and coordIndex node 2512.Coord node 2511 has the coordinate information about summit 0,1 and 2, that is, and and [0.0 1.12.0,1.0 0.1 2.0,2.0 1.1 2.0].CoordIndex node 2512 has and the corresponding summit 0,1 and 2 of information about the face of object 2530.

Pretreatment unit receives original VRML model 2510 according to an exemplary embodiment of the present invention, definite triangle that will be subsided, and calculate the summit that subsides.With reference to Figure 25, owing to have only a triangle in the object 2530, so be confirmed as will be by the triangle that be subsided for this triangle, and the subside coordinate figure on summit of hypothesis is (1.0 0.76 2.0).In this case, the coordinate figure on the summit that subsides, (1.0 0.76 2.0) are located in the end of the coord node 2521 in the LOD VRML model 2520 according to an exemplary embodiment of the present invention.In LOD VRML model 2520, should be rearranged with the order of subsiding coordIndex node 2522 intermediate cam shapes.Yet, in exemplary embodiment shown in Figure 25, have only a triangle that will be subsided, therefore, the coordIndex node 2521 that comprises in coordIndex node 2522 and the original VRML model 2510 is identical.Owing to have only a triangle that will be subsided, so lodSequence node 2523 has value " 1 ".CoordStart node 2524 has positional information " 3 ", the position of the coordinate information on the summit that subsides that its indication is arranged in coord node 2521.UpdateDist node 2525 is set to " 0 ", and minScreenArea node 2526 is set to " 0.08 ".

In exemplary embodiment shown in Figure 25, has only a triangle that will be subsided.Two the leg-of-mutton situations that will be subsided are described below.

Figure 26 A illustrates coloured object 2600.Object 2600 has 8 summits on summit 0 to 7.

Figure 26 B illustrates the original VRML model 2610 of the object 2600 that is used for shown in Figure 26 A.For object 2600, have only coordinate information shown in Figure 26 B, but also can exist such as other attribute information of texture and color.With reference to Figure 26 B, the coordinate information on the corresponding summit 0 to 7 that coloured object 2600 is comprised is arranged among the coord 2611.The coordinate information on summit 0 is represented as " x0, y0, z0 ", and the coordinate information on summit 1 is represented as " x1, y1, z1 ".The coordinate information on other summit is represented in an identical manner.About face, that is, the leg-of-mutton information of forming coloured object 2600 is arranged among the coordIndex 2612.

Receive the pretreatment unit of original VRML model 2610 according to an exemplary embodiment of the present, use is calculated each leg-of-mutton error amount about the information on summit 0 to 7 with about the information that is included in the face among the coordIndex2612 about being included among the coord 2611, and rearranges triangle among the coordIndex 2612 according to described error amount.Figure 26 C illustrates the LOD VRML model of being created by pretreatment unit 2620.

The triangle that let us hypothesis is defined respectively by two groups of summits (6,7,0) and (3,4,5) is confirmed as the triangle that will quilt be subsided.In LOD VRML model 2620, about the information of face with triangle subsided series arrangement among coordIndexs 2622 thereafter.With reference to Figure 26 C, be positioned in the end of coordIndex 2622 about the leg-of-mutton information m1 that will at first be subsided.Return with reference to Figure 26 A, when the triangle by set of vertices (6,7,0) definition was subsided, the triangle of sharing two summits with the described triangle that subsides was also subsided.That is, by set of vertices (6,2,7), the triangle that (6,0,2) and (0,7,1) define respectively is with determining that the triangle that will at first be subsided is subsided.Here, be arranged among the coordIndex 2622 before the information m1 about leg-of-mutton information m2, the m3 that will be subsided with the triangle of determining at first to be subsided and m4.

Subsided owing to be confirmed as second, so be arranged on before the information m4 about the leg-of-mutton information m5 that second quilt subsided by the triangle of set of vertices (3,4,5) definition.Return with reference to Figure 26 A, when the triangle by set of vertices (3,4,5) definition is subsided, also subsided with the triangle on shared two summits of the described triangle that subsides.That is, by set of vertices (2,4,3), the triangle that (1,3,5) and (0,5,4) define respectively is with being subsided by second triangle that subsides.Here, about being arranged among the coordIndex 2622 before the information m5 with the leg-of-mutton information m6, the m7 that determine to be subsided by second triangle that subsides and m8.Other leg-of-mutton description will be omitted.

To be comprised among the lodSequence2623 according to the triangle order leg-of-mutton quantity of being subsided of subsiding.As mentioned above, lodSequence 2623 indication shown in Figure 26 C is when the transformation carried out from LOD level 0 to LOD level 1, with set of vertices (6,7,0) four triangles of Lian Jieing are subsided, and when the transformation carried out from LOD level 1 to LOD level 2, with set of vertices (3,4,5) four triangles of Lian Jieing are subsided.Value among the lodSequence 2623 " 1 " is as separating two LOD levels.

After the triangle that will be subsided in determining coloured object 2600, pretreatment unit of the present invention calculates the summit that subsides that subsides and create by leg-of-mutton.Be positioned in the end of the coord 2621 in the LOD VRML model 2620 about the information on the summit that subsides that calculates.Owing in exemplary embodiment of the present, there are two triangles to be confirmed as and will to be subsided, thus two summits that subside be created, and have coordinate figure respectively (x8, y8, z8), (x9, y9, z9).

Information about the position of the coordinate information on the summit that subsides is included among the coordStart 2624 that is included in LOD VRML model 2620.With reference to Figure 26 C, coordStart 2624 comprises value " 9 ".Therefore, rendering unit obtains first coordinate information that subsides the summit from the 9th position of coord 2621.Rendering unit can obtain the coordinate information on second summit that subsides from a certain position of coord 2621, and described position adds 1 by the value with coordStart 2624 and obtains.

Except above-mentioned exemplary embodiment, exemplary embodiment of the present also can be by carrying out medium, for example, in the computer-readable medium/on computer readable code/instructions realize.Medium can be corresponding with the medium/media of the storage of any permission computer-readable code and/or transmission.

Can be according to variety of way with computer readable code/instructions record/be sent on the medium, the example of described medium comprises that magnetic storage medium (for example, ROM, floppy disk, hard disk etc.), random access memory, optical recording media (for example, CD-ROM or DVD) with such as the storage/transmission media of carrier wave, as be exemplified as and pass through the internet.Described medium can also be a distributed network, thereby computer readable code/instructions is stored/transmits and carry out in the mode that distributes.Computer readable code/instructions can be carried out by one or more processors.

As mentioned above, according to the present invention, can in having the system of limited resources, carry out playing up of 3D object effectively.The present invention can be used to embedded system, this embedded system is played up the 3D data effectively, and it is loaded in the terminal device, described terminal device is played up the 3D telematics systems of a large amount of 3D geometry deformation data, the PDA(Personal Digital Assistant) or the phone of low performance effectively such as being used for.

Although illustrated and described exemplary embodiments more of the present invention, but it should be appreciated by those skilled in the art that: without departing from the principles and spirit of the present invention, can change these exemplary embodiments, scope of the present invention is limited by claim and equivalent thereof.

Claims (53)

1, a kind of conversion comprises the method for the graph data of at least one leg-of-mutton object, and this method comprises:

Definite at least one triangle that will be subsided at least one triangle in being included in object;

Determining will be by the summit that subsides that described at least one triangle is subsided and creates; And

Based on coming the graph data of transforming object about described definite at least one the leg-of-mutton information that will be subsided with about the information on definite summit that subsides.

2, determine that the method for claim 1, wherein described at least one triangle that will be subsided comprises:

When definite triangle in being included in object is removed object is played up the minimum parameter of influence; And

Based on definite at least one triangle that will be subsided of described parameter.

3, the method for claim 1, wherein described summit of determining to subside comprises: the tangent plane tangent plane based on leg-of-mutton three summits of described at least one that will be subsided and described three summits is calculated the summit that subsides.

4, the method for claim 1, wherein described summit of determining to subside comprises: calculate the attribute information on the summit that subsides based on leg-of-mutton three summits of described at least one that will be subsided.

5, method as claimed in claim 4, wherein, the subside attribute information on summit of described calculating comprises: the mean value on leg-of-mutton three summits that use will be subsided, or reflect the feature on three summits.

6, a kind of method of graph data of transforming object adaptively, this method comprises:

Reception comprises about the information on the summit of object with about the graphical model that is included at least one the leg-of-mutton information in the object and comprises one or more leg-of-mutton objects with expression;

Determine at least one triangle that will be subsided in the triangle in being included in object, and determine will be by the summit that subsides that described at least one triangle is subsided and creates;

Establishment comprises about described determines at least one the leg-of-mutton information that will be subsided and about the graphical model of the information on the summit that subsides determined;

Graph data based on the graphical model transforming object of creating; And

Rendering objects.

7, method as claimed in claim 6, wherein, described definite described at least one triangle and the summit that subsides comprise:

Definition is included in each triangle in the object is played up the effect of generation to object the error metrics of designator as indication;

Based on error metrics to being included in each the triangle error of calculation value in the object; And

Determine that based on the error amount that calculates described at least one triangle and the triangle that will be subsided subside in proper order.

8, a kind of conversion adaptively comprises the method for the graph data of one or more leg-of-mutton objects, and this method comprises:

Definition is included in each triangle in the object is played up the effect of generation to object the error metrics of designator as indication;

Based on error metrics to being included in each the triangle error of calculation value in the object; And

The triangle that has minimum error values in the error amount that calculates is at first subsided.

9, method as claimed in claim 8, wherein, described definition error metrics comprises: definition as about the error of each leg-of-mutton geometric properties with about the error of described leg-of-mutton attributive character and error metrics.

10, method as claimed in claim 9, wherein, at least one that whether is positioned at the border based on leg-of-mutton radius-of-curvature, this triangle area and triangle in whole grid determined the error about each leg-of-mutton geometric properties.

11, method as claimed in claim 9, wherein, determine error based at least one of the variation of the change in color between triangle and the adjacent triangle, the variation of texture coordinate value between them and the normal between them about leg-of-mutton attributive character.

12, method as claimed in claim 8, wherein, described diabolo subsides and comprises:

The establishment summit that subsides replaces described triangle;

Based on the annexation of subsiding between the triangle of summit change in being included in object; And

Create the new graph data of object based on the annexation that changes.

13, a kind of in being expressed as the object that comprises one or more leg-of-mutton graph datas triangle being subsided is the method on summit, and this method comprises:

Lip-deep normal for each definition grid on leg-of-mutton three summits that will be subsided;

Definition is used for the tangent plane on described leg-of-mutton each summit, and described tangent plane comprises the summit, and vertical with normal corresponding to the summit;

It is on three tangent planes of each definition on three summits that the central point on described leg-of-mutton three summits is projected to, thereby obtains three subpoints; And

Obtain to subside the summit by the mean value that calculates three subpoints.

14, method as claimed in claim 13 also comprises: based on the property value on leg-of-mutton three summits that will be subsided obtain the to subside property value on summit.

15, method as claimed in claim 14, wherein, the subside property value on summit of described acquisition comprises: the mean value on leg-of-mutton three summits that use will be subsided.

16, method as claimed in claim 14, wherein, the subside property value on summit of described acquisition comprises: the feature on leg-of-mutton three summits that reflection will be subsided.

17, method as claimed in claim 16, wherein, the subside property value on summit of described acquisition comprises: the mode that the texture coordinate value on the summit that subsides is had the greatest impact by the texture coordinate value on the summit on the summit of approaching most to subside in leg-of-mutton three summits that will be subsided obtain the to subside texture coordinate value on summit.

18, method as claimed in claim 16, wherein, obtain the to subside property value on summit comprises: the mode that the normal vector on the summit that subsides is had the greatest impact by the normal vector on the summit on the summit of approaching most to subside in the spherical coordinates system in leg-of-mutton three summits that will be subsided obtain the to subside normal vector on summit.

19, method as claimed in claim 16, wherein, the subside property value on summit of described acquisition comprises: the color on leg-of-mutton three summits that reservation will the be subsided color on summit that realizes subsiding.

20, a kind of establishment is used for the method for graphical model that conversion adaptively comprises the graph data of a plurality of leg-of-mutton objects, and this method comprises:

Determine the summit that subsides that the triangle that will be subsided in the object, triangle subside order and will subside and create by diabolo;

Be created in the triangle identifier node that wherein subsides and be arranged in proper order with triangle about the leg-of-mutton information that is included in the object;

Generation comprises the subside LOD order node of order information of triangle;

Be created in the coordinate node that the coordinate information on the coordinate information on the summit of object wherein and the summit that subsides is arranged; And

Generation relates to the vertex position node that subsides of position of the coordinate information on the summit that subsides that is positioned at the coordinate node.

21, method as claimed in claim 20, wherein, describedly determine to comprise:

Object is played up the corresponding error metrics of parameter of the effect of generation and come based on being included in each triangle in the object being included in each the triangle error of calculation value in the object with expression; And

Determine that triangle subsides order so that early subsided by the triangle with less error amount.

22, method as claimed in claim 20 also comprises:

Generation comprises and being used at the more new node of a plurality of leg-of-mutton information of subsiding gradually between the level that subsides; And

Produce node, this node comprises about begin the information of the leg-of-mutton level that subsides from it in object.

23, method as claimed in claim 20, further comprising the steps of at least one:

Produce the color node, in this node, be arranged with the colouring information and the colouring information on summit of subsiding on the summit of object, and produce the vertex color node that subsides, this vertex color node that subsides relates to the position of the colouring information that is arranged in the summit that subsides in the described color node;

Produce the normal node, in this node, be arranged with the normal information on the normal information that is included in the summit in the object and the summit that subsides, and produce the vertex normal node that subsides, this vertex normal node that subsides relates to the position of the normal information that is arranged in the summit that subsides in the described normal node; And

Produce the texture coordinate node, in this node, be arranged with the texture coordinate information and the texture coordinate information on summit of subsiding on the summit of object, and producing the vertex texture coordinate node that subsides, this vertex texture coordinate node that subsides relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

24, method as claimed in claim 20, further comprising the steps of at least one:

Produce the color node, in this node, be arranged with except about by the colouring information on the summit of the formation object the leg-of-mutton colouring information that subsides;

Produce the normal node, in this node, be arranged with the normal information on the normal information that is included in the summit in the object and the summit that subsides, and produce the vertex normal node that subsides, this vertex normal node that subsides relates to the position of the normal information that is arranged in the summit that subsides in the described normal node; And

Produce the texture coordinate node, in this node, be arranged with the texture coordinate information on the texture coordinate information on the summit that is included in the object and the summit that subsides, and producing the vertex texture coordinate node that subsides, this vertex texture coordinate node that subsides relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

25, a kind of method of creating the Virtual Reality Modeling Language model, described Virtual Reality Modeling Language model are used for the graph data that comprises a plurality of leg-of-mutton objects is carried out adaptive transformation, and this method comprises:

Determine the summit that subsides that triangle, the triangle that will be subsided subside order and will subside and create by diabolo in object;

Produce the coordIndex node, in this node, about being included in leg-of-mutton information in the object by the triangle series arrangement of subsiding;

Produce the IodSequence node, it comprises the triangle order information that subsides;

Produce the coord node, in this node, be arranged with the coordinate information on summit of object and the coordinate information on the summit that subsides; And

Produce the coordStart node, it relates to the position of the coordinate information that is arranged in the node that subsides in the described coord node.

26, method as claimed in claim 25, further comprising the steps of at least one:

Produce the normalIndex node, in this node, the series arrangement of subsiding by diabolo about each the leg-of-mutton information that is included in the object, produce the normal node, in this node, be arranged with the normal information on the normal information that is included in the summit in the object and the summit that subsides, and produce the normalStart node, this node relates to the position of the normal information that is arranged in the summit that subsides in the described normal node;

Produce the colorIndex node, in this node, the series arrangement of subsiding by diabolo is about being included in each the leg-of-mutton information in the object, produce the color node, in this node, be arranged with the colouring information and the colouring information on summit of subsiding on the summit of object, and produce the colorStart node, this node relates to the position of the colouring information that is arranged in the summit that subsides in the described color node; And

Produce the texcoordIndex node, in this node, the series arrangement of subsiding by diabolo is about being included in each the leg-of-mutton information in the object, produce the texture coordinate node, in this node, be arranged with the texture coordinate information and the texture coordinate information on summit of subsiding on the summit of object, and produce the texcoordStart node, this node relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

27, method as claimed in claim 25, further comprising the steps of at least one:

Produce the normalIndex node, in this node, the series arrangement of subsiding by diabolo about each the leg-of-mutton information that is included in the object, produce the normal node, in this node, be arranged with the normal information on the normal information that is included in the summit in the object and the summit that subsides, and produce the normalStart node, this node relates to the position of the normal information that is arranged in the summit that subsides in the described normal node;

Produce the colorIndex node, in this node, the series arrangement of subsiding by diabolo produces the color node about being included in each the leg-of-mutton information in the object, in this node, be arranged with the colouring information on the summit of the object except the quilt leg-of-mutton colouring information that subsides; With

Produce the texcoordIndex node, in this node, the series arrangement of subsiding by diabolo is about being included in each the leg-of-mutton information in the object, produce the texture coordinate node, in this node, be arranged with the texture coordinate information and the texture coordinate information on summit of subsiding on the summit of object, and produce the texcoordStart node, this node relates to the position of the texture coordinate information that is arranged in the summit that subsides in the described texture coordinate node.

28, a kind ofly be used for the equipment that conversion comprises the view data of one or more leg-of-mutton objects, this equipment comprises:

Pretreatment unit is determined at least one triangle that will be subsided among the triangle in being included in object, determine the summit that subsides by described at least one triangle is subsided and creates; With

Rendering unit is come the graph data of transforming object based on what determined by pretreatment unit about described at least one the leg-of-mutton information that will be subsided and about the information on the summit that subsides determined, and is carried out object and play up.

29, equipment as claimed in claim 28 wherein, is played up the parameter with minimum influence to object when the definite triangle in being included in object of pretreatment unit is removed, and is determined described at least one triangle that will be subsided based on described parameter.

30, equipment as claimed in claim 28, wherein, pretreatment unit calculates the summit that subsides based on the tangent plane on leg-of-mutton three summits of described at least one that will be subsided and described three summits.

31, a kind of equipment that is used for the graph data of object is carried out adaptive transformation, this equipment comprises:

Pretreatment unit, be used for receiving and comprise about the information on the summit that is included in object with about being included at least one leg-of-mutton information in the object, expression comprises the graphical model of described at least one leg-of-mutton object, determine at least one triangle that will be subsided among the triangle in being included in object, determine the summit that subsides by described at least one triangle is subsided and creates, and establishment graphical model, described graphical model comprise about described at least one leg-of-mutton information of determining to be subsided and about the information on the summit that subsides determined; With

Rendering unit is used for the graph data based on the graphical model transforming object of creating, and rendering objects.

32, equipment as claimed in claim 31, wherein, pretreatment unit definition is included in the error metrics of the parameter of the influence degree that each triangle in the object plays up object as indication, to being included in each the triangle error of calculation value in the object, and determine described at least one triangle that will be subsided and the triangle order of subsiding based on described error metrics based on the error amount that calculates.

33, a kind of equipment that is used for the graph data that comprises one or more leg-of-mutton objects is carried out adaptive transformation, this equipment comprises:

Pretreatment unit, be used for defining as the error metrics of designator and based on described error metrics to being included in each triangle error of calculation value of object, described designator indication is included in the influence degree that each triangle in the object is played up object; With

Rendering unit is used for the triangle that has minimum error values among the error amount that calculates is at first subsided, and rendering objects.

34, equipment as claimed in claim 33, wherein, pretreatment unit with error metrics be defined as about the sum of errors of each leg-of-mutton geometric properties about the error of described leg-of-mutton attributive character and.

35, equipment as claimed in claim 34, wherein, based on leg-of-mutton radius-of-curvature, this triangle in whole grid area and this triangular form whether be arranged in the border at least one determine error about each leg-of-mutton geometric properties.

36, equipment as claimed in claim 34, wherein, determine error based in the variation of the change in color between triangle and the adjacent triangle, the variation of texture coordinate value between them and the normal between them at least one about leg-of-mutton attributive character.

37, equipment as claimed in claim 33, wherein, pretreatment unit is created the summit that subsides replacing described triangle and to change annexation between the triangle that is included in the object based on the described summit that subsides, and rendering unit is created the new graph data of object based on the annexation that changes.

38, a kind of establishment is used for the equipment of graphical model that conversion adaptively comprises the graph data of one or more leg-of-mutton objects, and this equipment comprises:

The error amount counter determines that based on the influence degree that each triangle that is included in the object is played up object the triangle and the triangle that will be subsided subside in proper order in object;

The summit counter that subsides is determined the summit that subsides that will create by the triangle that subsides; With

The graphical model creator, produce triangle identifier node, in this node, about be included in the object triangle with triangle subside order be arranged, produce comprise triangle subside order information LOD order node, produce the coordinate node, the coordinate information that is included in the coordinate information on the summit in the object and the summit that subsides in this node is arranged, and producing the vertex position node that subsides, it relates to the position of the coordinate information on the summit that subsides that is arranged in coordinate vertices.

39, equipment as claimed in claim 38, wherein, the error amount counter comes being included in each the triangle error of calculation value in the object based on the corresponding error metrics of parameter that is included in the influence degree that each triangle in the object plays up object with indication, and definite triangle order of subsiding, the triangle that has less error amount is thus early subsided.

40, equipment as claimed in claim 38, wherein, the graphical model creator also produces and comprises and being used at the more new node of leg-of-mutton information of subsiding gradually between the level that subsides, and produces and comprise about begin the node of the information of the leg-of-mutton level that subsides from it in object.

41, equipment as claimed in claim 38, wherein, the graphical model creator also produces at least one in following:

The color node, in this node, the colouring information that is included in the colouring information on the summit in the object and the summit that subsides is arranged; With the vertex color node that subsides, relate to the position of the colouring information that is arranged in the summit that subsides in the color node;

The normal node, in this node, the normal information that is included in the normal information on the summit in the object and the summit that subsides is arranged and the vertex normal node that subsides, and relates to the position of the normal information that is arranged in the summit that subsides in the normal node; With

The texture coordinate node, in this node, the texture coordinate information that is included in the texture coordinate information on the summit in the object and the summit that subsides is arranged; With the vertex texture coordinate node that subsides, relate to the position of the texture coordinate information that is arranged in the summit that subsides in the texture coordinate node.

42, equipment as claimed in claim 38, therein, the graphical model creator also produces at least one in following:

The color node is in this node, except the colouring information about the summit of the formation object the leg-of-mutton colouring information that subsides is arranged;

The normal node, in this node, the normal information that is included in the normal information on the summit in the object and the summit that subsides is arranged; With the vertex normal node that subsides, relate to the position of the normal information that is arranged in the summit that subsides in the normal node; With

The texture coordinate node, in this node, the texture coordinate information that is included in the texture coordinate information on the summit in the object and the summit that subsides is arranged; With the vertex texture coordinate node that subsides, relate to the position of the texture coordinate information that is arranged in the summit that subsides in the texture coordinate node.

43, a kind of establishment is used for the equipment of Virtual Reality Modeling Language model that conversion adaptively comprises the graph data of a plurality of leg-of-mutton objects, and this equipment comprises:

The error amount counter determines that based on the influence degree that each triangle that is included in the object is played up object the triangle and the triangle that will be subsided subside in proper order in object;

The summit counter that subsides is determined the summit that subsides that will create by the triangle that subsides; With

The graphical model creator, produce the colorIndex node, in this node, be arranged, produce the lodsequence node about the information that is included in the object with the triangle order of subsiding, this node comprises the triangle order information that subsides, and produces the coord node, and the coordinate information that is included in the coordinate information on the summit in the object and the summit that subsides in this node is arranged, and producing the coordStart node, it relates to the position of the coordinate information that is arranged in the summit that subsides in the coord node.

44, equipment as claimed in claim 43, wherein, the graphical model creator also produces at least one in following:

The normalIndex node therein, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; The normal node, in this node, the normal information that is included in the normal information on the summit in the object and the summit that subsides is arranged; With the normalStart node, relate to the normal information that is arranged in the summit that subsides in the normal node;

The colorIndex node in this node, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; The color node, in this node, the colouring information that is included in the colouring information on the summit in the object and the summit that subsides is arranged; With the colorStart node, relate to the colouring information that is arranged in the summit that subsides in the color node; With

The texcoordIndex node in this node, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; The texture coordinate node in this node, comprises that the texture coordinate information on the texture coordinate information on the summit in the object and the summit that subsides is arranged; With the texcoordStart node, relate to the texture coordinate information that is arranged in the summit that subsides in the texture coordinate node.

45, equipment as claimed in claim 43, wherein, the graphical model creator also produces at least one in following:

The normalIndex node in this node, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; The normal node, in this node, the normal information that is included in the normal information on the summit in the object and the summit that subsides is arranged; With the normalStart node, relate to the position of the normal information that is arranged in the summit that subsides in the normal node;

The colorIndex node in this node, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; With the color node, in this node, the colouring information on the summit of the object except the leg-of-mutton colouring information that subsides is arranged; With

The texcoordIndex node in this node, is arranged with the leg-of-mutton order of subsiding about each the leg-of-mutton information that is included in the object; The texture coordinate node, in this node, the texture coordinate information on the texture coordinate information on the summit of object and the summit that subsides is arranged; With the texcoordStart node, relate to the information of the texture coordinate information that is arranged in the summit that subsides in the texture coordinate node.

46, at least a storage control is used to carry out the computer-readable medium of instruction of at least one processor that the graph data that comprises at least one leg-of-mutton object is carried out the method for conversion, and described method comprises:

Definite at least one triangle that will be subsided at least one triangle in being included in object;

Definite summit that subsides of creating by described at least one triangle that subsides; With

Based on coming the graph data of transforming object about definite described at least one the leg-of-mutton information that will be subsided with about the information on definite summit that subsides.

47, at least a storage control is used to carry out the computer-readable medium of instruction of at least one processor that graph data to object carries out the method for conversion adaptively, and described method comprises:

Receive graphical model, this graphical model comprises about the information that is included in the summit in the object with about at least one the leg-of-mutton information that is included in the object and comprises described at least one leg-of-mutton object with expression;

Determine at least one triangle that to be subsided in the triangle in being included in object, and determine will be by the summit that subsides that described at least one triangle is subsided and creates;

Establishment comprises about described at least one leg-of-mutton information of determining to be subsided with about the graphical model of the information on the summit that subsides determined;

Graph data based on the graphical model transforming object of creating; And

Rendering objects.

48, the computer-readable medium of at least a storage instruction, at least one carries out the processor that the graph data that comprises at least one leg-of-mutton object is carried out the method for adaptive transformation described instruction control, and described method comprises:

Definition is as the error metrics of designator, the effect that each triangle that comprises in this designator denoted object applies the expression of object;

Based on error metrics each triangle error of calculation value to comprising in the object; And

At first be collapsed upon the triangle that has minimum error amount in the error amount that calculates.

49, the computer-readable medium of at least a storage instruction, at least one carries out described instruction control in being expressed as the object that comprises one or more leg-of-mutton graph datas, and triangle is subsided is the processor of the method on summit, and described method comprises:

Lip-deep normal to each grid of leg-of-mutton three summits definition that will be subsided;

To described leg-of-mutton each summit definition tangent plane, described tangent plane comprises described summit and perpendicular to the normal corresponding with described summit;

The central point on described leg-of-mutton three summits is projected on three tangent planes to each definition on three summits, obtain the point of three projections thus; And

The mean value of the point by calculating three projections obtains the summit that subsides.

50, the computer-readable medium of at least a storage instruction, at least one carry out to create the processor of method that is used for the graph data that comprises a plurality of leg-of-mutton objects is carried out the graphical model of adaptive transformation described instruction control, and described method comprises:

Determine subside order and will be by to the described leg-of-mutton summit that subsides that subsides and create of triangle, the triangle that will be subsided in the object;

Be created in wherein the leg-of-mutton information that comprises about object with the triangle triangle identifier node that order arranges that subsides;

Generation comprises subside level of detail (LOD) the order node of order information of triangle;

Be created in the coordinate node that the coordinate information on the coordinate information on the summit that object wherein comprises and the summit that subsides is arranged; And

The generation vertex position node that subsides, it relates to is the position of coordinate information that is arranged in the summit that subsides of coordinate node.

51, the computer-readable medium of at least a storage instruction, at least one carry out to create the processor of method that is used for the graph data that comprises a plurality of leg-of-mutton objects is carried out Virtual Reality Modeling Language (VRML) model of adaptive transformation described instruction control, and described method comprises:

Determine subside order and will be by to the described leg-of-mutton summit that subsides that subsides and create of triangle, the triangle that will be subsided in the object;

Be created in wherein the leg-of-mutton information that comprises about object with the triangle coordIndex node that order arranges that subsides;

Generation comprises the subside lodSequence node of order information of triangle;

Be created in the coord node that the coordinate information on the coordinate information on the summit that object wherein comprises and the summit that subsides is arranged; And

Produce the coordStart node, it relates to the position of the coordinate information on the summit that subsides of arranging in the coord node.

52, a kind of conversion comprises the method for the graph data of a plurality of leg-of-mutton objects, and described method comprises:

Definite at least one triangle that will be subsided in a plurality of triangles;

Determining will be by the summit that subsides of described at least one triangle establishment of subsiding; And

Come the graph data of transforming object based on determining described at least one triangle that will be subsided and the summit that subsides.

53, the computer-readable medium of at least one storage instruction, at least one carries out the processor of method that conversion comprises the graph data of a plurality of leg-of-mutton objects described instruction control, and described method comprises:

In a plurality of triangles, determine at least one triangle that will be subsided;

Determining will be by the summit that subsides of described at least one triangle establishment of subsiding; And

Come the graph data of transforming object based on determining described at least one triangle that will be subsided and the summit that subsides.

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