CN111210520A - Reverse forming method and system for physical model - Google Patents
Reverse forming method and system for physical model Download PDFInfo
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Abstract
The invention discloses a reverse forming method for a physical model, which comprises the following steps: scanning the physical model to obtain point cloud information of the physical model; converting the obtained point cloud information into a polygonal mesh model; performing technical processing on the polygonal mesh obtained by conversion; constructing a CAD curved surface according to the processed polygonal mesh; the invention also discloses a reverse forming system for the physical model, which comprises the following modules: a scanning module; a point cloud conversion module; a polygon processing module; a CAD curved surface construction module; the invention can meet the requirements of high precision and strict reverse engineering and product design by accurately and reversely forming the physical model, reaches the international similar level and fills the domestic blank.
Description
Technical Field
The invention belongs to the technical field of computers, and particularly relates to a reverse forming method and system for a physical model.
Background
With the development of computer technology, CAD technology has become an important tool for product designers to research and develop, and the three-dimensional modeling technology has been widely applied to various aspects of product and mold design, scheme review, automated manufacturing, management and maintenance by the manufacturing industry; in actual development and manufacturing processes, the technical data received by the designer may be three-dimensional models of various data types, but often, physical models of products are obtained from upstream manufacturers, and the designer encounters difficulty in converting the physical models into CAD three-dimensional models.
Disclosure of Invention
In view of the defects in the prior art, the invention provides a reverse forming method and a system for a physical model, which can meet the requirements of high-precision and strict reverse engineering and product design.
In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:
a reverse forming method for a physical model, comprising the steps of:
scanning the physical model to obtain point cloud information of the physical model;
converting the obtained point cloud information into a polygonal mesh model;
performing technical processing on the polygonal mesh obtained by conversion;
and constructing the CAD curved surface according to the processed polygonal mesh.
According to an aspect of the present invention, the scanning the physical model to obtain the point cloud information of the physical model includes: and carrying out slice scanning on the special workpieces to obtain local point clouds, and then carrying out later-stage repair through the system to combine the local point clouds into complete point cloud information.
According to an aspect of the present invention, the converting the obtained point cloud information into the polygonal mesh model specifically includes: and converting the plurality of point clouds into a polygonal mesh through encapsulation, and forming a polygonal mesh model by the plurality of polygonal meshes obtained through point cloud conversion.
According to one aspect of the invention, the following steps are performed after the obtained point cloud information is converted into the polygonal mesh model: carving figures or characters on the polygonal mesh; and performing polygon mesh modification on the polygon mesh according to the carved figures or characters.
According to one aspect of the invention, said subjecting the transformed polygon mesh to a technical process comprises the steps of: the number of the polygon meshes is reduced; carrying out regularization treatment on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and performing perfection processing on the polygonal meshes.
According to one aspect of the invention, the number of reduced polygon meshes comprises the steps of: carrying out surface curvature calculation on the polygonal mesh model to generate a contour line; converting the contour line into a curvature dividing line by adjusting; creating a plurality of curvature regions on the basis of the curvature dividing lines; and reducing the number of polygonal meshes in the curvature area.
According to one aspect of the invention, the constructing the CAD surface based on the processed polygon meshes comprises the following steps: converting each created curvature area into a local CAD curved surface; the connection between the local CAD curved surfaces is completed by extending the curvature dividing line; and fitting each local CAD curved surface to obtain a final CAD curved surface.
A reverse forming system for a mock-up comprising the following modules:
the scanning module is used for scanning the physical model to obtain point cloud information;
the point cloud conversion module is used for converting the obtained point cloud information into a polygonal mesh model;
the polygon processing module is used for carrying out technical processing on the polygon meshes obtained by conversion;
and the CAD curved surface construction module is used for constructing the CAD curved surface according to the processed polygonal mesh.
According to one aspect of the invention, the reverse forming system for the physical model further comprises a feature alignment module, a feature extraction module and a feature extraction module, wherein the feature alignment module is used for scanning the special workpieces in a slicing mode and combining local point clouds into complete data; the carving module is used for carving the figures or characters on the polygon; and the modification module is used for performing polygon modification on the polygon meshes according to the carved figures or characters.
According to one aspect of the invention, a reduction module for reducing the number of polygonal meshes; the basic processing module is used for carrying out regularization processing on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and the advanced processing module is used for performing perfection processing on the polygonal meshes.
The implementation of the invention has the advantages that: the reverse forming method for the physical model comprises the following steps: scanning the physical model to obtain point cloud information of the physical model; converting the obtained point cloud information into a polygonal mesh model; performing technical processing on the polygonal mesh obtained by conversion; constructing a CAD curved surface according to the processed polygonal mesh; the invention is oriented to specialized point clouds and grid processing platforms of reverse engineering, rapid forming and additive manufacturing, converts the point clouds obtained by scanning into grid models, applies a unique algorithm to rapidly simplify the number and shape of polygons, provides various repairing, fairing and processing methods, further generates CAD models, performs curved surface analysis, detection and the like, can meet the requirements of high-precision and strict reverse engineering and product design, can be used in the fields of product design, 3D printing and additive manufacturing, self-adaptive precision detection, cultural relic restoration, VR \ AR models, large scene display and the like, reaches the international similar level, and fills the domestic blank.
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 embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a reverse forming method for a physical model according to a first embodiment of the present invention;
FIG. 2 is a simplified result diagram of a polygon mesh according to a first embodiment of the present invention;
FIG. 3 is a schematic diagram of a reverse forming method for a mock-up according to the second embodiment of the present invention;
FIG. 4 is a schematic view of a reverse forming system for a mock-up according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
As shown in fig. 1 and 2, a reverse forming method for a physical model includes the following steps:
step S1: scanning the physical model to obtain point cloud information of the physical model;
in practical applications, the physical model may be scanned by any device with a point cloud scanning function, and preferably, the present embodiment scans the physical model by a computer to obtain a discrete point cloud information map.
In practical applications, the point cloud information refers to a set of vectors in a three-dimensional coordinate system. These vectors are usually expressed in terms of X, Y, Z three-dimensional coordinates and are generally used primarily to represent the shape of the external surface of an object. Not so, the point cloud data may represent RGB color, gray value, depth, segmentation result, etc. of one point in addition to the geometric position information represented by (X, Y, Z).
In practical application, scanning the physical model to obtain point cloud information of the physical model specifically includes: and carrying out slice scanning on the special workpieces to obtain local point clouds, and then carrying out later-stage repair through the system to combine the local point clouds into complete point cloud information.
In practical applications, the physical model may be any model with a practical shape, and preferably, the physical model in this embodiment is a 3D physical model.
In practical application, the special workpiece is a complex workpiece with a plurality of curved surfaces, each curved surface needs to be scanned in a partition mode, point cloud information of each area is obtained respectively, and then the point cloud information of each area is combined into complete point cloud information through a system.
In practical application, after point cloud information is obtained, the point cloud information needs to be sorted and edited.
Step S2: converting the obtained point cloud information into a polygonal mesh model;
in practical application, converting the obtained point cloud information into a polygonal mesh model specifically comprises: and converting the plurality of point clouds into a polygonal mesh through encapsulation, and forming a polygonal mesh model by the plurality of polygonal meshes obtained through point cloud conversion.
In practical application, the point cloud information is converted into a mesh model by a surface reconstruction method, and complete point cloud information of the physical model is expressed by a plurality of polygonal meshes.
In the present embodiment, the polygonal mesh model is exemplified by a 3D mesh model.
In practical application, the polygon mesh model is required to be sorted and edited after being converted into the polygon mesh model.
In practical applications, the polygonal mesh model may be composed of any polygonal mesh, and the present embodiment takes a triangular mesh as an example.
Step S3: performing technical processing on the polygonal mesh obtained by conversion;
in practical application, the technical processing of the transformed polygon mesh comprises the following steps: the number of the polygon meshes is reduced; carrying out regularization treatment on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and performing perfection processing on the polygonal meshes.
In practical applications, reducing the number of polygon meshes comprises the following steps: carrying out surface curvature calculation on the polygonal mesh model to generate a contour line; converting the contour line into a curvature dividing line by adjusting; creating a plurality of curvature regions on the basis of the curvature dividing lines; and reducing the number of polygonal meshes in the curvature area.
In practical application, the regularization treatment of the polygonal mesh is specifically to realize regularization of the polygonal mesh through hole filling, feature removal, mesh doctor, plane section, sand paper and relaxation, so that the surface of the polygonal mesh becomes smoother.
In practical application, the refining processing of the polygonal mesh is specifically to use a hole filling command to repair lost data, restore corners of a model by using a sharpening guide, trim polygons from a plane section, and create a reference to align the polygonal mesh to a world coordinate system.
In practical applications, a unique algorithm is employed to create the curvature region.
In practical applications, the unique algorithm specifically includes the following steps:
step S301: generating a contour line and converting the contour line into a curvature dividing line by calculating based on the curvature of the curved surface;
in practical applications, the contour lines are generated according to the curvature change of the curved surface, and represent the contour of the physical model.
In practical application, the contour line is edited and converted into a curvature dividing line.
In practical application, the curvature dividing line has three forms of a straight line, a curved line and a circle.
In practical application, the curvature dividing line divides the polygon mesh obtained by the initial conversion.
In practical application, the curvature dividing lines are connected, and the connection position is the intersection point of the curvature dividing lines.
In practical application, the curvature dividing line intersection point is automatically generated depending on the curvature dividing line: if the non-end point position on the existing curvature dividing line is captured, the curvature dividing line is automatically divided, and an intersection point is generated; if the position of an end point on the existing curvature dividing line is captured, if the end point has an intersection point, attaching to the intersection point; if not, an intersection is automatically generated.
In practical applications, if the curvature dividing line does not intersect with other dividing lines, the end point is an isolated end point.
In practical application, the curvature dividing line can be created in a self-defined mode according to actual needs, and the created curvature dividing line end points automatically capture the intersection points of the generated curvature dividing lines, the points on the curvature dividing lines and the points on the grids in sequence according to the priority.
Step S302: editing the curvature dividing line, and adjusting the shape of the curve through various types of pinch points to form a dividing region;
in practical application, the shape of the curvature dividing line can be adjusted by adjusting the intersection point of the curvature dividing line.
In practical application, the position of the curvature dividing line can be adjusted by adjusting the isolated end point.
In practical application, if the curvature dividing line is a curve, the curve is provided with an intermediate pinch point, and the shape of the curvature dividing line can be adjusted by adjusting the intermediate pinch point.
In practical applications, the curvature dividing line which is not a straight line can be converted into a straight line.
In practical application, the adjusted curvature dividing line divides the initial mesh to form a divided region.
Step S303: solving the problem that the obtained grid surface is uneven by referring to a plane;
in practical application, the reference plane is a virtual plane, and the generated curvature dividing lines are projected onto the reference plane to ensure the flatness of the grid surface.
Step S304: if the curvature split line is not on the plane, adjusting by adding a coplanarity constraint;
in practical application, curvature dividing lines are picked up first, and then a constraint mode is selected; the constraint mode comprises an adaptive mode and a top view mode, a front view mode and a left view mode.
In practical application, the self-adaptive mode is that a plane is automatically fitted according to the selected curvature dividing line end points, and all curvature dividing lines and curvature dividing line intersection points are projected onto the plane.
In practical application, the overlooking, foresight and left-looking modes are that according to the normal vectors of the overlooking, foresight and left-looking directions of the WCS, the central point of the selected curvature dividing line is automatically calculated to construct a plane, and all the curvature dividing lines and the intersection points of the curvature dividing lines are projected onto the plane.
Step S305: creating a curvature region on the basis of the curvature dividing line;
in practical application, curvature dividing lines are sequentially picked up, a possibly formed region is automatically searched, and meanwhile, the normal vector direction of the region is judged according to the visual direction.
In practical applications, the same curvature dividing line may be a boundary line on two adjacent curvature regions, and if not the desired region, the curvature dividing line may be continuously added until the desired region is generated.
In practical applications, if an open curvature segment line is picked (i.e., the end points are not curvature segment line intersections), then a hint cannot be generated.
In practical application, a plurality of curvature areas are created on the polygonal mesh model and are divided by curvature dividing lines.
In practical application, after the created curvature area is determined, the number of the polygonal meshes in the selected curvature area is reduced, and a reduction result is output.
In practical application, the simplified proportion of the number of the polygonal meshes can be manually selected, and the shape and the details of the curved surface are not influenced by the simplified number of the polygonal meshes.
In practical applications, all regions may be selected to be cleared and all curvature regions may be deleted.
In practical application, the discrete precision can be set, the number of discrete sections of the curvature dividing line is controlled, and the integrity of the curvature dividing line can be ensured only by controlling the number of discrete sections of different curvature dividing lines to be consistent.
In practical application, after the number of polygonal meshes is reduced, the regularization of the polygons is realized through hole filling, feature removal, mesh doctor, plane section, sand paper and relaxation, so that the surfaces of the polygons become smoother.
In practical application, the filling holes are used for detecting and filling holes of the polygonal model; the effect of the removal feature is to delete the selected triangle and fill the resulting hole; the mesh doctor is used for automatically repairing the defects in the polygonal mesh; the effect of the slack/sandpaper is to minimize the angle between the individual polygons.
In practical application, the regularization of the polygon is realized, so that the polygonal surface becomes smoother and a foundation can be laid for the subsequent construction of a CAD curved surface.
In practical applications, after the above steps are implemented, the lost data is repaired by using a hole filling command, corners of the model are restored by using a sharpening guide, polygons are trimmed by using plane sections, and a reference is created to align the polygons to a world coordinate system to further perfect the processing of the polygon mesh model.
Step S4: and constructing the CAD curved surface according to the processed polygonal mesh.
In practical application, the method for constructing the CAD curved surface according to the processed polygon meshes comprises the following steps: converting each created curvature area into a local CAD curved surface; the connection between the local CAD curved surfaces is completed by extending the curvature dividing line; and fitting each local CAD curved surface to obtain a final CAD curved surface.
In practical application, each previously created curvature area is converted into a CAD surface, and the conversion process is very fast and simple because a series of processes are previously performed on the polygon meshes in the area.
In practical application, the curvature dividing line is extended to enable all the CAD curved surfaces to be intersected, so that the whole CAD curved surface can be conveniently generated through fitting.
In practical application, the fitting of each curved surface can adopt a bicubic surface method or a least square method.
The embodiment provides a reverse forming method for a physical model, which is characterized in that point cloud obtained by scanning is converted into a grid model, a unique algorithm is applied to quickly simplify the number and shape of polygons, various repairing, fairing and processing methods are provided, a CAD model is further generated, curved surface analysis, detection and the like are performed, high-precision and strict reverse engineering and product design requirements can be met, the method can be used in the fields of product design, 3D printing and material increase manufacturing, self-adaption precision detection, cultural relic restoration, VR \ AR models, large scene display and the like, the international similar level is achieved, and the domestic blank is filled.
Example two
As shown in fig. 2 and 3, a reverse forming method for a physical model includes the following steps:
step S1: scanning the physical model to obtain point cloud information of the physical model;
in practical applications, the physical model may be scanned by any device with a point cloud scanning function, and preferably, the present embodiment scans the physical model by a computer to obtain a discrete point cloud information map.
In practical applications, the point cloud information refers to a set of vectors in a three-dimensional coordinate system. These vectors are usually expressed in terms of X, Y, Z three-dimensional coordinates and are generally used primarily to represent the shape of the external surface of an object. Not so, the point cloud data may represent RGB color, gray value, depth, segmentation result, etc. of one point in addition to the geometric position information represented by (X, Y, Z).
In practical application, scanning the physical model to obtain point cloud information of the physical model specifically includes: and carrying out slice scanning on the special workpieces to obtain local point clouds, and then carrying out later-stage repair through the system to combine the local point clouds into complete point cloud information.
In practical applications, the physical model may be any model with a practical shape, and preferably, the physical model in this embodiment is a 3D physical model.
In practical application, the special workpiece is a complex workpiece with a plurality of curved surfaces, each curved surface needs to be scanned in a partition mode, point cloud information of each area is obtained respectively, and then the point cloud information of each area is combined into complete point cloud information through a system.
In practical application, after point cloud information is obtained, the point cloud information needs to be sorted and edited.
Step S2: converting the obtained point cloud information into a polygonal mesh model;
in practical application, converting the obtained point cloud information into a polygonal mesh model specifically comprises: and converting the plurality of point clouds into a polygonal mesh through encapsulation, and forming a polygonal mesh model by the plurality of polygonal meshes obtained through point cloud conversion.
In practical application, the point cloud information is converted into a mesh model by a surface reconstruction method, and complete point cloud information of the physical model is expressed by a plurality of polygonal meshes.
In the present embodiment, the polygonal mesh model is exemplified by a 3D mesh model.
In practical application, the polygon mesh model is required to be sorted and edited after being converted into the polygon mesh model.
In practical applications, the polygonal mesh model may be composed of any polygonal mesh, and the present embodiment takes a triangular mesh as an example.
Step S3: carving figures or characters on the polygonal mesh;
in practical application, the adjustment information required to be carried out by the polygonal mesh is recorded by engraving graphics or characters on the polygonal mesh.
Step S4: carrying out polygon mesh modification on the polygon mesh according to the carved image file;
in practical application, the polygon mesh is modified according to the recorded adjustment information required by the polygon mesh.
Step S5: performing technical processing on the polygonal mesh obtained by conversion;
in practical application, the technical processing of the transformed polygon mesh comprises the following steps: the number of the polygon meshes is reduced; carrying out regularization treatment on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and performing perfection processing on the polygonal meshes.
In practical applications, reducing the number of polygon meshes comprises the following steps: carrying out surface curvature calculation on the polygonal mesh model to generate a contour line; converting the contour line into a curvature dividing line by adjusting; creating a plurality of curvature regions on the basis of the curvature dividing lines; and reducing the number of polygonal meshes in the curvature area.
In practical application, the regularization treatment of the polygonal mesh is specifically to realize regularization of the polygonal mesh through hole filling, feature removal, mesh doctor, plane section, sand paper and relaxation, so that the surface of the polygonal mesh becomes smoother.
In practical application, the refining processing of the polygonal mesh is specifically to use a hole filling command to repair lost data, restore corners of a model by using a sharpening guide, trim polygons from a plane section, and create a reference to align the polygonal mesh to a world coordinate system.
In practical applications, a unique algorithm is employed to create the curvature region.
In practical applications, the unique algorithm specifically includes the following steps:
step S501: generating a contour line and converting the contour line into a curvature dividing line by calculating based on the curvature of the curved surface;
in practical applications, the contour lines are generated according to the curvature change of the curved surface, and represent the contour of the physical model.
In practical application, the contour line is edited and converted into a curvature dividing line.
In practical application, the curvature dividing line has three forms of a straight line, a curved line and a circle.
In practical application, the curvature dividing line divides the polygon mesh obtained by the initial conversion.
In practical application, the curvature dividing lines are connected, and the connection position is the intersection point of the curvature dividing lines.
In practical application, the curvature dividing line intersection point is automatically generated depending on the curvature dividing line: if the non-end point position on the existing curvature dividing line is captured, the curvature dividing line is automatically divided, and an intersection point is generated; if the position of an end point on the existing curvature dividing line is captured, if the end point has an intersection point, attaching to the intersection point; if not, an intersection is automatically generated.
In practical applications, if the curvature dividing line does not intersect with other dividing lines, the end point is an isolated end point.
In practical application, the curvature dividing line can be created in a self-defined mode according to actual needs, and the created curvature dividing line end points automatically capture the intersection points of the generated curvature dividing lines, the points on the curvature dividing lines and the points on the grids in sequence according to the priority.
Step S502: editing the curvature dividing line, and adjusting the shape of the curve through various types of pinch points to form a dividing region;
in practical application, the shape of the curvature dividing line can be adjusted by adjusting the intersection point of the curvature dividing line.
In practical application, the position of the curvature dividing line can be adjusted by adjusting the isolated end point.
In practical application, if the curvature dividing line is a curve, the curve is provided with an intermediate pinch point, and the shape of the curvature dividing line can be adjusted by adjusting the intermediate pinch point.
In practical applications, the curvature dividing line which is not a straight line can be converted into a straight line.
In practical application, the adjusted curvature dividing line divides the initial mesh to form a divided region.
Step S503: solving the problem that the obtained grid surface is uneven by referring to a plane;
in practical application, the reference plane is a virtual plane, and the generated curvature dividing lines are projected onto the reference plane to ensure the flatness of the grid surface.
Step S504: if the curvature split line is not on the plane, adjusting by adding a coplanarity constraint;
in practical application, curvature dividing lines are picked up first, and then a constraint mode is selected; the constraint mode comprises an adaptive mode and a top view mode, a front view mode and a left view mode.
In practical application, the self-adaptive mode is that a plane is automatically fitted according to the selected curvature dividing line end points, and all curvature dividing lines and curvature dividing line intersection points are projected onto the plane.
In practical application, the overlooking, foresight and left-looking modes are that according to the normal vectors of the overlooking, foresight and left-looking directions of the WCS, the central point of the selected curvature dividing line is automatically calculated to construct a plane, and all the curvature dividing lines and the intersection points of the curvature dividing lines are projected onto the plane.
Step S505: creating or deleting curvature regions;
in practical application, curvature dividing lines are sequentially picked up, a possibly formed region is automatically searched, and meanwhile, the normal vector direction of the region is judged according to the visual direction.
In practical applications, the same curvature dividing line may be a boundary line on two adjacent curvature regions, and if not the desired region, the curvature dividing line may be continuously added until the desired region is generated.
In practical applications, if an open curvature segment line is picked (i.e., the end points are not curvature segment line intersections), then a hint cannot be generated.
In practical application, a plurality of curvature areas are created on the polygonal mesh model and are divided by curvature dividing lines.
In practical application, after the created curvature area is determined, the number of the polygonal meshes in the selected curvature area is reduced, and a reduction result is output.
In practical application, the simplified proportion of the number of the polygonal meshes can be manually selected, and the shape and the details of the curved surface are not influenced by the simplified number of the polygonal meshes.
In practical applications, all regions may be selected to be cleared and all curvature regions may be deleted.
In practical application, the discrete precision can be set, the number of discrete sections of the curvature dividing line is controlled, and the number of discrete sections of different curvature dividing lines is required to be controlled to be consistent.
In practical application, after the number of polygonal meshes is reduced, the regularization of the polygons is realized through hole filling, feature removal, mesh doctor, plane section, sand paper and relaxation, so that the surfaces of the polygons become smoother.
In practical application, the filling holes are used for detecting and filling holes of the polygonal model; the effect of the removal feature is to delete the selected triangle and fill the resulting hole; the mesh doctor is used for automatically repairing the defects in the polygonal mesh; the effect of the slack/sandpaper is to minimize the angle between the individual polygons.
In practical application, the regularization of the polygon is realized, so that the polygonal surface becomes smoother and a foundation can be laid for the subsequent construction of a CAD curved surface.
In practical applications, after the above steps are implemented, the lost data is repaired by using a hole filling command, corners of the model are restored by using a sharpening guide, polygons are trimmed by using plane sections, and a reference is created to align the polygons to a world coordinate system to further perfect the processing of the polygon mesh model.
Step S6: and constructing the CAD curved surface according to the processed polygonal mesh.
In practical application, the method for constructing the CAD curved surface according to the processed polygon meshes comprises the following steps: converting each created curvature area into a local CAD curved surface; the connection between the local CAD curved surfaces is completed by extending the curvature dividing line; and fitting each local CAD curved surface to obtain a final CAD curved surface.
In practical application, each previously created curvature area is converted into a CAD surface, and the conversion process is very fast and simple because a series of processes are previously performed on the polygon meshes in the area.
In practical application, the curvature dividing line is extended to enable all the CAD curved surfaces to be intersected, so that the whole CAD curved surface can be conveniently generated through fitting.
In practical application, the fitting of each curved surface can adopt a bicubic surface method or a least square method.
The embodiment provides a reverse forming method for a physical model, which is characterized in that point cloud obtained by scanning is converted into a grid model, a unique algorithm is applied to quickly simplify the number and shape of polygons, various repairing, fairing and processing methods are provided, a CAD model is further generated, curved surface analysis, detection and the like are performed, high-precision and strict reverse engineering and product design requirements can be met, the method can be used in the fields of product design, 3D printing and material increase manufacturing, self-adaption precision detection, cultural relic restoration, VR \ AR models, large scene display and the like, the international similar level is achieved, and the domestic blank is filled.
Reverse forming system embodiment for physical model
As shown in fig. 4, a reverse forming system for a mock-up of a physical object, the reverse forming system for a mock-up of a physical object comprises the following modules:
the scanning module 1 is used for scanning the physical model to obtain point cloud information;
the point cloud conversion module 2 is used for converting the obtained point cloud information into a polygonal mesh model;
a polygon processing module 3, configured to perform technical processing on the converted polygon meshes;
and the CAD curved surface construction module 4 is used for constructing the CAD curved surface according to the processed polygonal meshes.
In practical application, the reverse forming system for the physical model further comprises a feature alignment module 5, a feature extraction module and a feature extraction module, wherein the feature alignment module is used for scanning the special workpieces in a slicing mode and combining local point clouds into complete data; the engraving module 6 is used for engraving figures or characters on the polygon; and the modification module 7 is used for performing polygon modification on the polygon meshes according to the carved figures or characters.
In practical applications, the polygon processing module includes the following modules: the simplification module is used for simplifying the number of the polygonal meshes through a unique algorithm; the basic processing module is used for carrying out regularization processing on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and the advanced processing module is used for performing perfection processing on the polygonal meshes.
In practical application, the reverse forming system for the physical model can be converted into a rapid mode, and point cloud processing is simplified into processes of importing, meshing, automatic hole repairing, smoothing and model outputting by providing a series of guiding functions.
In practical application, the fast mode comprises a functional area module, a model manager module, a graphic display area module, an immediate menu module and a status bar module.
The embodiment provides a reverse forming system for a physical model, which can process huge amounts of point clouds and grids, can repair multiple ring holes at the same time, has the original functions of automatic grid tracking simplification and interactive grid simplification and rapid forming, can build a lightweight grid model based on a million-level grid, is used as a platform to support and integrate into various industrialized solutions, and can be converted into a rapid mode through a guide function, so that the operation is simplified, and the use threshold is reduced.
The implementation of the invention has the advantages that: the reverse forming method for the physical model comprises the following steps: scanning the physical model to obtain point cloud information of the physical model; converting the obtained point cloud information into a polygonal mesh model; performing technical processing on the polygonal mesh obtained by conversion; constructing a CAD curved surface according to the processed polygonal mesh; the invention is oriented to specialized point clouds and grid processing platforms of reverse engineering, rapid forming and additive manufacturing, converts the point clouds obtained by scanning into grid models, applies a unique algorithm to rapidly simplify the number and shape of polygons, provides various repairing, fairing and processing methods, further generates CAD models, performs curved surface analysis, detection and the like, can meet the requirements of high-precision and strict reverse engineering and product design, can be used in the fields of product design, 3D printing and additive manufacturing, self-adaptive precision detection, cultural relic restoration, VR \ AR models, large scene display and the like, reaches the international similar level, and fills the domestic blank.
The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (10)
1. A reverse forming method for a physical model, characterized by comprising the steps of:
scanning the physical model to obtain point cloud information of the physical model;
converting the obtained point cloud information into a polygonal mesh model;
performing technical processing on the polygonal mesh obtained by conversion;
and constructing the CAD curved surface according to the processed polygonal mesh.
2. The method of claim 1, wherein the scanning the physical model to obtain the point cloud information of the physical model comprises: and carrying out slice scanning on the special workpieces to obtain local point clouds, and then carrying out later-stage repair through the system to combine the local point clouds into complete point cloud information.
3. The method of claim 2, wherein the converting the point cloud information into the polygon mesh model comprises: and converting the plurality of point clouds into a polygonal mesh through encapsulation, and forming a polygonal mesh model by the plurality of polygonal meshes obtained through point cloud conversion.
4. The method of claim 1, wherein the step of converting the point cloud information into a polygonal mesh model comprises: carving figures or characters on the polygonal mesh; and performing polygon mesh modification on the polygon mesh according to the carved figures or characters.
5. The inverse forming method for physical model according to claim 1, wherein said subjecting the transformed polygonal mesh to technical processing comprises the steps of: the number of the polygon meshes is reduced; carrying out regularization treatment on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and performing perfection processing on the polygonal meshes.
6. The inverse forming method for the physical model according to claim 5, wherein the number of the reduced polygon meshes comprises the steps of: carrying out surface curvature calculation on the polygonal mesh model to generate a contour line; converting the contour line into a curvature dividing line by adjusting; creating a plurality of curvature regions on the basis of the curvature dividing lines; and reducing the number of polygonal meshes in the curvature area.
7. The inverse forming method for physical models according to claim 6, wherein the constructing the CAD surface from the processed polygon meshes comprises the steps of: converting each created curvature area into a local CAD curved surface; the connection between the local CAD curved surfaces is completed by extending the curvature dividing line; and fitting each local CAD curved surface to obtain a final CAD curved surface.
8. A reverse forming system for a mock-up, comprising the following modules:
the scanning module is used for scanning the physical model to obtain point cloud information;
the point cloud conversion module is used for converting the obtained point cloud information into a polygonal mesh model;
the polygon processing module is used for carrying out technical processing on the polygon meshes obtained by conversion;
and the CAD curved surface construction module is used for constructing the CAD curved surface according to the processed polygonal mesh.
9. The system of claim 8, further comprising a feature alignment module for slice scanning a special type of workpiece and merging local point clouds into a complete data; the carving module is used for carving the figures or characters on the polygon; and the modification module is used for performing polygon modification on the polygon meshes according to the carved figures or characters.
10. The inverse forming system for physical models according to claim 9, wherein the polygon processing module comprises the following modules: the simplification module is used for simplifying the number of the polygonal meshes; the basic processing module is used for carrying out regularization processing on the polygonal mesh to enable the surface of the polygonal mesh to be smoother; and the advanced processing module is used for performing perfection processing on the polygonal meshes.
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