CN113674294A

CN113674294A - 3D model slice processing method and device

Info

Publication number: CN113674294A
Application number: CN202110969629.7A
Authority: CN
Inventors: 蒲灵峰; 沈鸿翔
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Technology Development Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Technology Development Co Ltd
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2021-11-19

Abstract

The invention discloses a 3D model slice processing method and a device, wherein the method comprises the following steps: acquiring a three-dimensional model; obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; determining a cutting area according to the direction reference quantity and the vector direction of the plurality of cutting intersecting lines; and generating a slicing result according to the cutting area and the three-dimensional model. The method can greatly reduce the calculation cost of the whole slicing processing process and obviously improve the slicing processing efficiency.

Description

3D model slice processing method and device

Technical Field

The invention relates to the technical field of computer graphics, in particular to a 3D model slice processing method and device.

Background

With continuous expansion and verticality fusion of the application field of computer graphics, the 3D model processing algorithm is continuously updated and iterated. The slicing algorithm is used as a tool which can be applied to most mainstream application scenes such as 3D model analysis, visual art, 3D printing and the like, and the updating and optimization of the slicing algorithm are significant. However, when the 3D model is sliced at present, it is necessary to determine the direction of the intersection line of the cutting plane and the surface element of the 3D model. In the prior art, multi-condition judgment is needed during judgment, and the intersecting line direction can be determined finally. This determination method is computationally intensive, resulting in inefficient slicing processing.

Disclosure of Invention

In view of the above problems, the invention provides a 3D model slice processing method and device, which can greatly reduce the computational overhead of the whole slice processing process and significantly improve the slice processing efficiency.

In a first aspect, the present application provides the following technical solutions through an embodiment:

a 3D model slice processing method, comprising:

acquiring a three-dimensional model; obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; determining a cutting area according to the direction reference quantity and the vector directions of the plurality of cutting intersecting lines; and generating a slicing result according to the cutting area and the three-dimensional model.

Optionally, the determining the reference amount of the direction according to the intersection line of the target normal direction and the target cutting includes:

and determining the deviation amount of the vector direction of the target cutting intersection line relative to the normal direction as the direction reference amount.

Optionally, the determining a cutting area according to the direction reference amount and the vector directions of the cutting intersecting lines includes:

for each cutting intersection line, judging whether the vector direction of the cutting intersection line is matched with the direction reference quantity or not; if so, determining the vector direction of the cutting intersection line as a connection direction; if not, determining the connection direction in the opposite direction of the vector direction of the cutting intersection line; and determining the cutting area according to the connecting direction of the plurality of cutting intersecting lines.

Optionally, the determining the cutting area according to the connection direction of the plurality of cutting intersecting lines includes:

and connecting the cutting intersecting lines according to the connecting direction of the cutting intersecting lines to obtain the cutting area.

Optionally, the connecting the plurality of cutting intersecting lines according to the connecting direction of the plurality of cutting intersecting lines to obtain the cutting region includes:

acquiring a first adjacent surface element according to a preset initial cutting intersection line; the first adjacent surface element is a surface element with coincident end points in the preset direction of the initial surface element, and the initial surface element is a surface element corresponding to the initial cutting intersection line; connecting the initial cutting intersection line and a first adjacent intersection line according to the connecting direction of the first adjacent intersection line to obtain a first folding line; the first adjacent intersection line is a cutting intersection line corresponding to the first adjacent surface element; acquiring a second adjacent surface element according to the first fold line; the second adjacent surface element is a surface element with coincident end points in the preset direction of the first adjacent surface element; connecting the first fold line with a second adjacent intersecting line according to the connecting direction of the second adjacent intersecting line to obtain a second fold line; the second adjacent intersection line is a cutting intersection line corresponding to the second adjacent surface element; and according to the second fold line, continuing connecting the rest cutting intersecting lines until the rest cutting intersecting lines are connected to the initial cutting intersecting line, and obtaining the cutting area.

Optionally, the generating a slicing result according to the cutting region and the three-dimensional model includes:

cutting the surface element corresponding to the cutting area according to the cutting area to obtain a cutting unit; judging whether the shape of each cutting unit is triangular or not; if yes, generating the visual cutting unit according to a preset generation rule; if not, generating a subunit of the cutting unit based on the diagonal vertex of the cutting unit; wherein the shape of the subunit is triangular; generating the visualized subunits according to a preset generation rule; and generating the slicing result according to the visualized cutting unit and the visualized sub-unit.

Optionally, the obtaining a plurality of cutting intersecting lines according to the preset slicing parameters and the three-dimensional model includes:

determining a cutting surface according to preset slicing parameters; and determining the plurality of cutting intersecting lines according to the position relation between the cutting surface and the surface element.

Optionally, the determining the plurality of cutting intersecting lines according to the position relationship between the cutting surface and the surface element includes:

for each surface element, judging whether the surface element is intersected with the cutting surface; when the surface element is intersected with the cutting surface, determining that the surface element has a cutting intersection line; and acquiring a cutting intersection line of the surface element according to the vertex coordinate of the surface element and the cutting surface.

Optionally, the surface element intersects the cutting plane, including any one or more of the following intersection conditions:

a first vertex of the facet is located on a first side of the cutting plane, and a second vertex of the facet is located on a second side of the cutting plane; the first vertex of the surface element is located on the first side of the cutting surface, and the second vertex and the third vertex of the surface element are located on the cutting surface.

Optionally, before determining the reference direction amount according to the intersection line of the target normal direction and the target cutting, the method further includes:

and deleting the surface element coincident with the cutting surface.

In a second aspect, based on the same inventive concept, the present application provides the following technical solutions through an embodiment:

a 3D model slice processing apparatus, comprising:

the generation module is used for acquiring a three-dimensional model; the first processing module is used for obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; the second processing module is used for determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; the third processing module is used for determining a cutting area according to the direction reference quantity and the vector directions of the cutting intersecting lines; and the slicing generation module is used for generating a slicing result according to the cutting area and the three-dimensional model.

In a third aspect, based on the same inventive concept, the present application provides the following technical solutions through an embodiment:

a computer-readable storage medium, on which a computer program is stored, which program, when being executed by a processor, is adapted to carry out the steps of the method according to any one of the preceding first aspects.

In a fourth aspect, based on the same inventive concept, the present application provides the following technical solutions through an embodiment:

a 3D printing system comprising a processor and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the 3D printing system to perform the steps of the method of any of the first aspects above.

According to the 3D model slice processing method and device provided by the embodiment of the invention, a three-dimensional model is obtained; then, obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; then, determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; then, determining a cutting area according to the direction reference quantity and the vector direction of the plurality of cutting intersecting lines; and finally, generating a slicing result according to the cutting area and the three-dimensional model. In the whole slicing processing process, the vector direction of the cutting intersection line is judged and adjusted based on the direction reference amount when the cutting area is obtained, and multi-condition judgment is not needed; therefore, the calculation cost of the whole slicing processing process is greatly reduced, the slicing processing efficiency is obviously improved, and the method can be applied to different scenes and has high universality.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts. In the drawings:

fig. 1 shows a flowchart of a 3D model slice processing method provided in an embodiment of the present invention;

fig. 2 is a schematic diagram showing a case where a surface element intersects a cut surface in the embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating the solution of the intersection of the cuts in an embodiment of the invention;

FIG. 4 is a diagram illustrating the slice edge effect when the slice precision is low in the embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating slice segmentation when the slice precision is high in the embodiment of the present invention;

fig. 6 shows a schematic structural diagram of a 3D model slice processing apparatus provided in an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The 3D model slicing processing method provided by the invention can be applied to any scene with slicing requirements on the 3D model; for example: 3D model parsing, visual art, 3D printing, etc. The method can be used as a functional module to be loaded or integrated into the 3D processing software of each scene; for example, the functional modules may be stored in the form of codes in a computer storage medium, and read and executed by a processor to implement the functional functions of the functional modules. The method and apparatus of the present invention will be described in detail below by way of specific examples.

Referring to fig. 1, a flowchart of a 3D model slice processing method according to an embodiment of the present invention is shown. The 3D model slice processing method comprises the following steps:

step S10: and acquiring the three-dimensional model.

In step S10, the three-dimensional model (3D model) may be created by using existing 3D software, for example, CAD (Computer Aided Design) software, to obtain a 3D model file in STL format; then, the STL format file is imported into a slicing processing flow pipeline in the 3D software capable of slicing, and a three-dimensional model is obtained. Meanwhile, the three-dimensional model data can be structurally optimized; for example, after structural optimization is performed and surface element data storage of the three-dimensional model is completed, whether two surface elements are adjacent or not can be judged by searching whether coincident points exist between the surface elements, so that computing resources can be saved, and processing efficiency can be improved. In addition, the type of the 3D software in this embodiment is not limited, and may be, for example, a 3D model parsing software, a 3D software for performing visual art creation, a 3D software for 3D printing, and the like; in addition, a three-dimensional model can be produced and generated through a computer graphic library (namely a graphic library used in self-programming); for example, (Open Graphics Library), directx (direct extension), and the like.

Then, in this embodiment, the three-dimensional model may be constructed as a complete and visual three-dimensional model, which is convenient for a user to observe in real time and adjust the slicing parameters subsequently, and the construction process is not limited.

Step S20: obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; and the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface.

In step S20, the preset slicing parameters are determined by the user according to the requirement, and different slicing parameters can be used in different application scenarios. Slicing parameters including cutting direction, slicing position, slicing thickness, slicing number, and slicing accuracy, etc. Wherein, the cutting direction is a direction perpendicular to the cutting surface or other designated directions; the slicing position is the position of a cutting surface; the thickness of the slices is the vertical distance between two adjacent slices; the slicing precision is to visually display the roughness and the flatness of the slices after the slicing result is obtained. The slicing precision can be selected to be high precision or low precision; when the slicing precision is selected to be low precision, the cutting area is not optimized before the slicing result is generated; when the slicing accuracy is selected to be high, the binning optimization can be performed on the sliced region before generating the slicing result, and the specific manner of the optimization will be described in the subsequent step S40.

For example, in 3D model parsing, a user may determine slice positions, number of slices, slice accuracy, and so on, depending on the location of the three-dimensional model parsing. In the 3D printing process, a user can determine the slice thickness and the slice precision according to the printing precision of the 3D printer and the required printing precision.

In some embodiments, the implementation of step S20 may be as follows:

firstly, according to preset slicing parameters, a cutting surface is determined.

For example, in an application scenario of 3D model parsing or visual art exhibition, the cutting surfaces may be determined according to the slice position and the cutting direction, and the number of the cutting surfaces may be one or more; in addition, the user can also specify a corresponding plane function or curved function to generate a cutting surface, and the cutting surface can be a plane or a curved surface without limitation. In an application scenario of 3D printing, a cutting plane may be determined according to any one or more of a cutting direction, a slice thickness, and a cutting accuracy; specifically, when the cutting direction is a direction perpendicular to the Z axis of the three-dimensional model, that is, the cutting surface is perpendicular to the Z axis of the three-dimensional model, a plurality of cutting surfaces may be taken at equal intervals along the Z axis.

It should be noted that the following description in this embodiment is made by taking one cutting surface as an example.

And then, determining a plurality of cutting intersecting lines according to the position relation between the cutting surfaces and the surface elements.

Specifically, for each surface element, whether the surface element is intersected with the cutting surface is judged; when the surface element is intersected with the cutting surface, determining that the surface element has a cutting intersection line; at this time, the cutting intersection line can be further calculated. And acquiring a cutting intersection line of the surface element according to the vertex coordinate and the cutting surface of the surface element.

The surface element intersects the cutting surface, including any one or more of the following intersection conditions:

1. the first vertex of the surface element is positioned on the first side of the cutting surface, and the second vertex of the surface element is positioned on the second side of the cutting surface; as shown in case 1 and case 2 in fig. 2.

2. The first vertex of the surface element is positioned on the first side of the cutting surface, and the second vertex and the third vertex of the surface element are positioned on the cutting surface; as in case 3 shown in fig. 2.

The intersection judgment is carried out according to the position relation characteristics 1 and 2, so that the judgment efficiency can be obviously improved.

Furthermore, in some embodiments, a bin may occur that coincides with the cut plane, as in case 4 shown in fig. 2; i.e. normal to the facet perpendicular to the cutting plane. The data that are invalid for these bins in forming the slicing result may be deleted before step S30 to reduce the data size of the final model and save computation. For example, in a 3D printing scene, a bin overlapping a cut plane does not need to be subjected to contour information formation and printing, that is, the bin is invalid information and can be deleted before step S30, so as to improve the slicing processing efficiency.

The specific process of calculating the cutting intersection line can be referred to as follows:

the above case 1 is taken as an example, and other intersection cases may be analogized. A line segment EF formed after the cutting surface intersects with the surface element is shown in fig. 3, the line segment EF is a cutting intersection line to be solved, and z ═ h is the cutting surface.

According to the general straight line analytic formula, the joint cutting surface z ═ h can be obtained:

therefore, the X, Y coordinates of intersection point E and intersection point F can be found as follows:

and obtaining an analytic expression of the cutting intersection line EF according to the intersection point E and the intersection point F. And calculating all surface elements corresponding to the intersection conditions 1, 2 and 3 to obtain all cutting intersection lines corresponding to the cutting surfaces.

Step S30: determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element.

In step S30, after the plurality of cutting intersections are acquired, it is necessary to perform reconnection of the cutting intersections in order to obtain a slice. When in connection, the connection is required according to a uniform vector direction, so that a graphics rendering pipeline is ensured to draw the surface elements according to a specific sequence, such as anticlockwise or clockwise connecting three vertexes of the surface elements; after the plotting, the normal vector orientation of each surface element is uniform. For example, if the normal vectors of a bin are all outward with respect to the three-dimensional model, then the bin is visible, and vice versa invisible. The Graphics rendering pipeline may be a Graphics rendering pipeline in OpenGL (Open Graphics Library), directx (direct extensible); wherein, when a graphics rendering pipeline in OpenGL performs rendering, a bin generated counterclockwise has a visible normal vector; when the graphics rendering pipeline in DirectX performs drawing, the bin generated clockwise has a visible normal vector.

Therefore, in the present embodiment, the vector direction of each cutting intersection line can be adjusted by determining a direction reference amount. The surface element selected by the determined direction reference amount can be arbitrarily specified by a user or randomly determined without limitation. Specifically, the deviation of the vector direction of the target cutting intersection line from the normal direction can be determined as the direction reference. The deflection amount may be a deflection direction, and may also include a deflection direction and a deflection angle.

Step S40: and determining a cutting area according to the direction reference quantity and the vector directions of the plurality of cutting intersecting lines.

In step S40, the following implementation procedure may be included:

first, for each cutting intersection:

judging whether the vector direction of the cutting intersection line is matched with the direction reference quantity or not; the deflection direction or deflection angle between the vector direction of the cutting intersection line and the normal direction of the corresponding surface element can be recorded as a deviation amount. At this time, whether to match or not can be divided into two implementation manners as follows: 1. if the deviation amount of the cutting intersection line is the same as the reference amount of the direction, the vector direction of the current cutting intersection line can be considered to be matched with the reference amount of the direction; and if not, the vector direction of the current cutting intersection line is not matched with the direction reference quantity. 2. If the deviation amount of the cutting intersection line is opposite to the reference amount of the direction, the vector direction of the current cutting intersection line can be considered to be matched with the reference amount of the direction; and if not, the vector direction of the current cutting intersection line is not matched with the direction reference quantity. It should be noted that the deviation amount and the direction reference amount can be vectors. Then, when the vector direction of the cutting intersection line is matched with the direction reference amount, determining the vector direction of the cutting intersection line as a connection direction; when the vector direction of the cutting intersection line is not matched with the reference direction amount, namely the vector direction is opposite, the connection direction can be determined by the opposite direction of the vector direction of the cutting intersection line; i.e. the vector direction of the cutting intersection is reversed. Thus, the vector direction (connection direction) of each cutting intersection line during connection is ensured to be the same.

In this embodiment, the vector direction of the cutting intersection line is adjusted by matching the cutting intersection line with the direction reference amount, so as to obtain the connection direction. Compared with the prior art that six groups of conditions are judged through the vertex drawing sequence of the surface element, and then the corresponding logic is called to adjust the vector direction of the cutting intersection line so as to obtain the connection direction, the process only needs to judge the conditions once for each cutting intersection line, the connection direction of one cutting intersection line can be determined, the calculated amount is greatly reduced, the logic judgment complexity is simplified, and the stability, the parallelism, the usability, the maintainability and the processing efficiency are improved.

And aiming at each cutting intersection line, the matching and adjusting processes are carried out to obtain the connecting directions of all the cutting intersection lines.

The cutting region, i.e. the position of the visualized part when cutting the three-dimensional model, may be the region surrounded by a closed polygon. Specifically, the cutting area may be determined based on the connection direction of the plurality of cutting intersections. In order to form the cutting area, a plurality of cutting intersecting lines may be connected, that is, the cutting intersecting lines may be connected according to a connecting direction of the cutting intersecting lines, so as to obtain the cutting area. When in connection, each cutting intersection line can be connected end to end according to the connection direction, and a plurality of cutting intersection lines can be connected simultaneously or sequentially according to the adjacent sequence without limitation.

For example, when the cutting lines are connected in sequence in the order of adjacency, the following implementation can be performed:

firstly, a preset initial cutting intersection line is determined, the initial cutting intersection line is any one cutting intersection line selected from a plurality of cutting intersection lines, and the initial cutting intersection line is used as a basis for connecting other cutting intersection lines.

Then, acquiring a first adjacent surface element according to a preset initial cutting intersection line; the first adjacent surface element is a surface element with coincident end points in the preset direction of the initial surface element, and the initial surface element is a surface element corresponding to the initial cutting cross line; when a first adjacent surface element is searched, all surface elements cut by the cutting surface can be read, then the surface elements with end points coincident with the initial surface elements are determined, and finally the surface elements in the preset direction are determined from the surface elements with end points coincident, namely the first adjacent surface element. The preset direction may be the same as the connection direction of the cutting intersection line, or may be opposite to the connection direction of the cutting intersection line, without limitation.

Then, according to the connecting direction of the first adjacent intersecting line, connecting the initial cutting intersecting line and the first adjacent intersecting line to obtain a first folding line; the first adjacent intersection line is a cutting intersection line corresponding to the first adjacent surface element. Then, acquiring a second adjacent surface element according to the first fold line; the process of acquiring the second adjacent surface element may refer to the process of acquiring the first adjacent surface element, and is not described in detail. The second adjacent surface element is a surface element with coincident end points in the preset direction of the first adjacent surface element; and connecting the first folding line with a second adjacent line according to the connecting direction of the second adjacent line to obtain a second folding line, wherein the second adjacent line is a cutting line corresponding to the second adjacent surface element. And repeating iteration continuously by analogy, namely continuously connecting the rest cutting intersecting lines according to the second folding line until the rest cutting intersecting lines are connected to the initial cutting intersecting line, and finally forming a closed polygonal area to obtain a cutting area.

Step S50: and generating a slicing result according to the cutting area and the three-dimensional model.

In step S50, after the cutting region is obtained, calculation processing may be performed according to the cutting region, and the three-dimensional model is cut and separated; when all cuts are completed, the desired slicing result is formed. In this embodiment, the following two specific implementation manners for obtaining the slicing result are provided:

1. for a high-precision three-dimensional model or a three-dimensional model with lower cutting precision requirement, the slicing precision can be selected to be low precision. At this time, the surface element where the cutting intersection line is located is not modified. For example, when the three-dimensional model is separated along the cutting region a, the slice 1 and the slice 2 may be formed, and the bin including the cutting intersection line may be separated into the slice 1 or the slice 2, without limitation. The specific separation of bins is as follows:

1) acquiring a vertex which is farthest away from the cutting intersection line on a surface element containing the cutting intersection line; the surface element is allocated to the slice corresponding to the farthest vertex, and the mode can ensure that the cut surface of the slice is smoother.

2) A positive direction is preset, surface elements containing cutting intersecting lines are distributed to the slices pointed by the positive direction, the mode is small in calculation amount, and the segmentation efficiency is high. As shown in fig. 4, in which all bins containing cutting intersections are assigned to the slice 1 pointed to by the positive direction.

3) On a surface element containing a cutting intersection line, acquiring the distance from three vertexes of the surface element to the cutting intersection line; then, the average distance of two vertices on the same side of the surface element (containing vertices coinciding with the cut intersection) from the cut intersection is determined. A distance threshold is then set to assign the bin, and if the average distance is less than the distance threshold, the bin may be assigned to the slice in which the two vertices are located. For example: and setting a distance threshold value r by the user, and if the average distance between two vertexes in the same direction in the divided surface element and the cutting intersection line is less than r, allocating the surface element to the slice where the two vertexes are positioned.

2. For a three-dimensional model with low precision or a three-dimensional model with higher cutting precision, the slicing precision can be selected to be high precision. At this time, the bin itself where the cutting intersection line is located may be modified. The present embodiment specifically has the following processing modes:

firstly, cutting a surface element corresponding to a cutting area according to the cutting area to obtain a cutting unit; and the cutting treatment is to calculate the surface element passed by the cutting intersecting line to obtain two cutting units formed by separating the surface element by the cutting intersecting line. The cutting unit is not visible at this point, i.e. no visualized slices have yet been generated.

Then, it is judged whether or not the shape of each cutting unit is triangular.

When the cutting unit is triangular, a visual cutting unit can be generated according to a preset generation rule; i.e. the cutting unit is drawn after the recombination of the slices is completed. The cutting unit does not need to carry out additional optimization processing, and can still ensure that a smooth slice edge is obtained.

When the cutting unit is not triangular, generating a sub-unit of the cutting unit based on the diagonal vertex of the cutting unit; wherein the shape of the subunit is triangular. Specifically, when determining the diagonal vertices of the cutting unit, a set of diagonal vertices may be randomly determined, and the cutting unit may be divided into two sub-units according to the determined diagonal vertices. And then, generating a visualized subunit according to a preset generation rule, namely drawing the subunit after the slice recombination is finished. And finally, recombining the three-dimensional model data according to the visualized cutting unit and the visualized subunits to generate a slicing result, as shown in fig. 5, wherein the edges of the slice 1 and the slice 2 are both flat and divided. By the optimization process, the surface element can be cut and recombined, the smoothness of the edge of the slice is ensured, and the roughness is reduced; the problem of unevenness after low-precision mode slicing processing is avoided.

In this embodiment, a step of determining a slicing result may be further added to determine whether the slicing result meets a preset requirement. The requirement condition indicates the flatness and roughness required to achieve the user. After the judgment, if a preset condition is reached, taking the slicing result as a final result; if the final condition can not be reached, adjusting the slicing parameters, returning to step S20, and re-executing steps S20-S50 until the final result meeting the requirement is obtained. The user can carry out transcoding output on the final result according to the requirement, and the transcoding mode is not limited.

In order to make the technical solution of the present embodiment easier to understand, the following description is given by taking a plurality of application scenarios as examples:

taking 3D model parsing application scenarios as an example:

this scenario can arise in industrial manufacturing processes, with the method embedded in 3D design software. For example, a plant design manager may in principle evaluate a mechanical part design that has some internal structures embedded therein that are not visible from outside the model. In this case, a slicing process of the three-dimensional model of the machine part is required to expose the internal structure. The operation core flow can be referred to as follows:

A. loading a data file of a design component into 3D design software;

B. the design software can analyze the design invisible data and present the design invisible data in a working area in a visual 3D model;

C. a user selects a design part and selects a cutting position to be cut or adopts a preset slicing mode; for example, a half cut, longitudinal or transverse cut 1/4, etc.;

D. a user clicks a slice function starting key; for example, the method can be implemented in various ways such as software toolbar icons, menu selection, automatic pop-up confirmation and the like;

E. the 3D design software calls the 3D model slice processing method disclosed in the embodiment to perform slice processing according to preset slice parameters, and finally, a slice result, namely a cut model, can be obtained;

F. and updating the cut model data to a working area by 3D design software in real time for a user to check and evaluate. In this case, the user can select a storage function or an export function for the slice result, and can select a desired storage format for export.

Taking the visual art application scene as an example:

the visual art mentioned in this embodiment refers to the art processing of the existing 3D model to present various artistic effects. Different from the 3D model parsing application scenario described above, are: after the 3D model is sliced by calling the method of this embodiment, the model generally needs to be artistic. Wherein, when the slicing is processed, any one or more of the following steps are included: slicing by location, slicing by distance, slicing by a specific function, and the like, without limitation; when artistic, any one or more of the following may be included: carrying out recombination, dyeing, material transformation, light and shadow effect, mapping, adding space background, adding action and the like on each section part without limitation; the final product is artistic. Another difference is that the processing of 3D models by the art industry is usually a multi-platform, cross-platform operation, often modeled and primarily completed in one piece of software, and then imported into another comprehensive engine for richer content operations. Particularly, after a cross-platform cloud cooperation platform comes out, the support for multi-person online editing is added. The data files can be transcoded uniformly, mutual compatibility is guaranteed, and real-time sharing and checking of cooperative design content are guaranteed.

Taking a 3D printing application scenario as an example:

in the 3D printing process, the designed 3D model data needs to be read into a special printer, and the 3D model is subjected to three-dimensional printing. With the development of technology, 3D printing has been expanded from the first models, toy printing, to various fields of machine part fabrication, house construction, high-precision structure manufacturing, and the like. When 3D printing is performed, the processing flow of the 3D model is as follows:

A. reading the 3D model data file into 3D printing design software; for example, STL files (a 3D print data file format);

B. the printing design software analyzes the model data in the STL file and constructs a visual 3D model to be displayed in the working area;

C. calling the 3D model slicing processing method of the embodiment to select slicing precision and perform equal-interval slicing processing according to different process requirements along a certain direction, such as the Z-axis direction of the 3D model, so as to obtain a series of two-dimensional plane information;

D. coupling the two-dimensional plane information in the step C with processing parameters of a 3D printer, and transcoding the two-dimensional plane information into a star-gcode file (a 3D printer execution instruction file) which can be identified by the 3D printer;

E. and the printer performs 3D printing according to the command of the star-gcode file.

In summary, in the 3D model slice processing method provided in this embodiment, a three-dimensional model is obtained; then, obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; then, determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; then, determining a cutting area according to the direction reference quantity and the vector direction of the plurality of cutting intersecting lines; and finally, generating a slicing result according to the cutting area and the three-dimensional model. In the whole slicing processing process, the vector direction of the cutting intersection line is judged and adjusted based on the direction reference amount when the cutting area is obtained, and multi-condition judgment is not needed; therefore, the calculation cost of the whole slicing processing process is greatly reduced, the slicing processing efficiency is obviously improved, and the method can be applied to different scenes and has high universality.

Referring to fig. 6, in another embodiment of the present invention, a 3D model slice processing apparatus 300 is provided, including:

a generating module 301, configured to obtain a three-dimensional model; the first processing module 302 is configured to obtain a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface; the second processing module 303 is configured to determine a direction reference according to a target normal and a target cutting intersection line; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element; a third processing module 304, configured to determine a cutting area according to the reference direction and the vector directions of the cutting intersection lines; a slicing generation module 305, configured to generate a slicing result according to the cutting region and the three-dimensional model.

As an optional implementation manner, the second processing module 303 is further specifically configured to:

As an optional implementation manner, the third processing module 304 is further specifically configured to:

As an optional implementation manner, the slice generating module 305 is specifically configured to:

As an optional implementation manner, the first processing module 302 is specifically configured to:

As an alternative embodiment, the surface element intersects the cut surface, including any one or more of the following intersections:

As an optional implementation, the method further includes: and the deleting module is used for deleting the surface element superposed with the cutting surface before determining the direction reference quantity according to the target normal direction and the target cutting intersection line.

It should be noted that, the implementation and technical effects of the 3D model slice processing apparatus 300 provided by the embodiment of the present invention are the same as those of the foregoing method embodiment, and for the sake of brief description, reference may be made to corresponding contents in the foregoing method embodiment where no mention is made in part of the apparatus embodiment.

In a further embodiment of the invention, a computer-readable storage medium is also provided, on which a computer program is stored which, when being executed by a processor, carries out any of the steps of the preceding method embodiments.

It should be noted that, the steps and technical effects achieved by the computer-readable storage medium provided by the embodiment of the present invention when the program is executed by the processor are the same as those of the foregoing method embodiment, and for the sake of brief description, no mention may be made in this embodiment, and reference may be made to the corresponding contents in the foregoing method embodiment.

There is also provided in yet another embodiment of the present invention a 3D printing system comprising a processor and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the 3D printing system to perform any of the steps of the preceding method embodiments.

It should be noted that, the implementation and technical effects of the 3D printing system provided by the embodiment of the present invention are the same as those of the foregoing method embodiment, and for a brief description, reference may be made to the corresponding contents in the foregoing method embodiment for the part of the embodiment of the present invention that is not mentioned.

The term "and/or" appearing herein is merely one type of associative relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship; the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A3D model slice processing method is characterized by comprising the following steps:

acquiring a three-dimensional model;

obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface;

determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element;

determining a cutting area according to the direction reference quantity and the vector directions of the plurality of cutting intersecting lines;

and generating a slicing result according to the cutting area and the three-dimensional model.

2. The method of claim 1, wherein determining a directional reference from the target normal and target cut intersection comprises:

3. The method of claim 1, wherein determining the cutting area based on the direction reference and the vector directions of the plurality of cutting intersections comprises:

for each cutting intersection line, judging whether the vector direction of the cutting intersection line is matched with the direction reference quantity or not;

if so, determining the vector direction of the cutting intersection line as a connection direction;

if not, determining the connection direction in the opposite direction of the vector direction of the cutting intersection line;

and determining the cutting area according to the connecting direction of the plurality of cutting intersecting lines.

4. The method of claim 3, wherein determining the cutting area according to the connection direction of the plurality of cutting intersections comprises:

5. The method according to claim 4, wherein the connecting the plurality of cutting cross lines according to the connecting direction of the plurality of cutting cross lines to obtain the cutting area comprises:

acquiring a first adjacent surface element according to a preset initial cutting intersection line; the first adjacent surface element is a surface element with coincident end points in the preset direction of the initial surface element, and the initial surface element is a surface element corresponding to the initial cutting intersection line;

connecting the initial cutting intersection line and a first adjacent intersection line according to the connecting direction of the first adjacent intersection line to obtain a first folding line; the first adjacent intersection line is a cutting intersection line corresponding to the first adjacent surface element;

acquiring a second adjacent surface element according to the first fold line; the second adjacent surface element is a surface element with coincident end points in the preset direction of the first adjacent surface element;

connecting the first fold line with a second adjacent intersecting line according to the connecting direction of the second adjacent intersecting line to obtain a second fold line; the second adjacent intersection line is a cutting intersection line corresponding to the second adjacent surface element;

and according to the second fold line, continuing connecting the rest cutting intersecting lines until the rest cutting intersecting lines are connected to the initial cutting intersecting line, and obtaining the cutting area.

6. The method of claim 1, wherein generating a slicing result from the cutting region and the three-dimensional model comprises:

cutting the surface element corresponding to the cutting area according to the cutting area to obtain a cutting unit;

judging whether the shape of each cutting unit is triangular or not;

if yes, generating the visual cutting unit according to a preset generation rule;

if not, generating a subunit of the cutting unit based on the diagonal vertex of the cutting unit; wherein the shape of the subunit is triangular; generating the visualized subunits according to a preset generation rule;

and generating the slicing result according to the visualized cutting unit and the visualized sub-unit.

7. The method of claim 1, wherein obtaining a plurality of cutting intersections according to the preset slicing parameters and the three-dimensional model comprises:

determining a cutting surface according to preset slicing parameters;

and determining the plurality of cutting intersecting lines according to the position relation between the cutting surface and the surface element.

8. The method of claim 7, wherein determining the plurality of cut intersections according to the positional relationship between the cut surface and the facet comprises:

for each surface element, judging whether the surface element is intersected with the cutting surface;

when the surface element is intersected with the cutting surface, determining that the surface element has a cutting intersection line;

and acquiring a cutting intersection line of the surface element according to the vertex coordinate of the surface element and the cutting surface.

9. The method of claim 8, wherein the facet intersects the cut plane, including any one or more of the following:

a first vertex of the facet is located on a first side of the cutting plane, and a second vertex of the facet is located on a second side of the cutting plane;

the first vertex of the surface element is located on the first side of the cutting surface, and the second vertex and the third vertex of the surface element are located on the cutting surface.

10. The method of claim 8, wherein prior to determining the orientation reference based on the target normal and target cut intersection, further comprising:

and deleting the surface element coincident with the cutting surface.

11. A 3D model slice processing apparatus, comprising:

the generation module is used for acquiring a three-dimensional model;

the first processing module is used for obtaining a plurality of cutting intersecting lines according to preset slicing parameters and the three-dimensional model; the cutting intersection line is a line segment of the intersection of the surface element of the three-dimensional model and the cutting surface;

the second processing module is used for determining a direction reference quantity according to the intersection line of the target normal direction and the target cutting; the target normal direction is the normal direction of any surface element, and the target cutting intersection line is the cutting intersection line of any surface element;

the third processing module is used for determining a cutting area according to the direction reference quantity and the vector directions of the cutting intersecting lines;

and the slicing generation module is used for generating a slicing result according to the cutting area and the three-dimensional model.

12. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 10.

13. A 3D printing system comprising a processor and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the 3D printing system to perform the steps of the method of any of claims 1-10.