Surface reduction method and device of grid model, electronic equipment and storage medium
By reducing the surface of the mesh model, identifying the vertices of the boundary area and constructing the target plane, the structural problems of the mesh model in the skeletal driving process are solved, and the structural correctness of the mesh model and the improvement of animation performance are achieved.
Patent Information
- Application Number
- CN202410431067.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-10
- Publication Date
- 2025-10-17
AI Technical Summary
Existing mesh model reduction methods cannot effectively deal with the impact of skeletal movement on the mesh model structure, resulting in structural problems such as interlacing, spikes and deformation after surface reduction, which cannot meet the needs of real scenes.
By reducing the faces of the original mesh model with bound bones, determining the second bones and weights bound to the vertices, identifying the vertices in the boundary area, constructing the target plane and determining the intersection, and dividing the faces belonging to the intersection into sub-faces, a new mesh model is generated.
It solves the structural problems of the mesh model after surface reduction during the skeleton driving process, ensures the structural correctness and animation performance of the mesh model, and improves the drivability and authenticity of the model.
Smart Images
Figure CN120807720A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] Embodiments of the present disclosure relate to the technical field of computer, and particularly, to a mesh model decimation method and device, electronic equipment and storage medium. BACKGROUND
[0002] Mesh model decimation can be understood as reducing the number of triangular patches under the premise of guaranteeing the geometric characteristics of the model, so as to reduce the data amount of the mesh model. The existing decimation method cannot effectively cope with the impact of bone movement on the structure of the mesh model. That is, in the process of driving the mesh model based on the bone after decimation, structural problems such as penetration, spiculation and deformation may occur, which cannot truly adapt to real scene requirements. SUMMARY
[0003] Embodiments of the present disclosure provide a mesh model decimation method and device, electronic equipment and storage medium, which can guarantee the structural correctness of the mesh model in the process of driving the bone after decimation.
[0004] In a first aspect, embodiments of the present disclosure provide a mesh model decimation method, comprising:
[0005] decimating the original mesh model bound with the bone to obtain a first model;
[0006] determining, according to the first bone bound with the plurality of vertices in the original mesh model and the first weight of the first bone, a second bone bound with the plurality of vertices in the first model and a second weight of the second bone;
[0007] determining, according to the second bone and the second weight, a vertex of a demarcation region in the first model; wherein the demarcation region includes a demarcation region between bones of different semantics;
[0008] constructing a target plane according to the vertices belonging to the same demarcation region, and determining an intersection point of the target plane and the first model;
[0009] dividing a patch to which the intersection point belongs into at least two sub-patches to obtain a second model.
[0010] In a second aspect, embodiments of the present disclosure further provide a mesh model decimation device, comprising:
[0011] a decimation module configured to decimate an original mesh model bound with a bone to obtain a first model;
[0012] a bone weight transplantation module configured to determine, according to a first bone bound with a plurality of vertices in the original mesh model and a first weight of the first bone, a second bone bound with the plurality of vertices in the first model and a second weight of the second bone;
[0013] a vertex determination module, configured to determine vertices of a boundary region in the first model according to the second skeleton and the second weight; wherein the boundary region includes a boundary region between skeletons of different semantics;
[0014] an intersection determination module, configured to construct a target plane based on vertices belonging to the same boundary area, and determine an intersection point between the target plane and the first model;
[0015] The patch generation module is used to divide the patch to which the intersection point belongs into at least two sub-patches to obtain a second model.
[0016] In a third aspect, an embodiment of the present disclosure further provides an electronic device, the electronic device comprising:
[0017] one or more processors;
[0018] a storage device for storing one or more programs,
[0019] When the one or more programs are executed by the one or more processors, the one or more processors implement the mesh model surface reduction method as described in any of the embodiments of the present disclosure.
[0020] In a fourth aspect, an embodiment of the present disclosure further provides a storage medium comprising computer-executable instructions, which, when executed by a computer processor, are used to execute the mesh model face reduction method as described in any one of the embodiments of the present disclosure.
[0021] The technical solution of the embodiment of the present disclosure is to reduce the surface area of the original mesh model with bound bones to obtain a first model; determine the second bone bound to multiple vertices in the first model and the second weight of the second bone based on the first bone bound to multiple vertices in the original mesh model and the first weight of the first bone; determine the vertices of the boundary area in the first model based on the second bone and the second weight; wherein the boundary area includes the boundary area between bones with different semantics; construct a target plane based on the vertices belonging to the same boundary area, and determine the intersection of the target plane and the first model; divide the face to which the intersection belongs into at least two sub-faces to obtain a second model.
[0022] The connection region of different semantic skeletons is a demarcation region with large deformation amplitude after the model reduction operation. By identifying the vertices in the demarcation region, a target plane is constructed based on the related information of the vertices in the demarcation region, and the intersection points can be obtained by cutting the first model using the target plane. These intersection points can be used as new boundary points in the model. By generating new facets based on these new boundary points, the grid facets in the region with large deformation amplitude can be refined, which can solve the structural problems such as penetration and spurs that occur in the process of driving the grid model based on the skeleton after reduction, and ensure the structural correctness of the grid model, so that the grid model has better animation performance. BRIEF DESCRIPTION OF DRAWINGS
[0023] The above and other features, advantages and aspects of embodiments of the present disclosure will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[0024] Figure 1 A flowchart of a mesh model reduction method provided by an embodiment of the present disclosure;
[0025] Figure 2 A schematic diagram of generating sub-facets in a mesh model reduction method provided by an embodiment of the present disclosure;
[0026] Figure 3 A flowchart of a mesh model reduction method provided by an embodiment of the present disclosure;
[0027] Figure 4 A flowchart of a mesh model reduction method provided by an embodiment of the present disclosure;
[0028] Figure 5 A structural schematic diagram of a mesh model reduction device provided by an embodiment of the present disclosure;
[0029] Figure 6 A structural schematic diagram of an electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION
[0030] Embodiments of the present disclosure will be described in more detail by referring to the attached drawings. Although certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms, and should not be interpreted as being limited to the embodiments set forth herein, but rather, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes, and are not intended to limit the scope of protection of the present disclosure.
[0031] It should be understood that each step recited in the method embodiments of the present disclosure can be performed in different orders and / or in parallel. In addition, the method embodiments can include additional steps and / or omit performing the steps shown. The scope of the present disclosure is not limited in this regard.
[0032] The term "comprises" and variations thereof used in the present disclosure are open-ended, that is, "comprising but not limited to". The term "based on" is "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Related definitions of other terms will be given in the description below.
[0033] It should be noted that the concepts of "first", "second", etc. mentioned in the present disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.
[0034] It should be noted that the modification of "one" or "multiple" mentioned in the present disclosure is illustrative and not limiting, and those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more".
[0035] The names of the messages or information exchanged between the plurality of devices in the embodiments of the present disclosure are only for illustrative purposes, and are not used to limit the scope of the messages or information.
[0036] Figure 1 A flowchart of a mesh model surface reduction method provided by an embodiment of the present disclosure is shown. The embodiment of the present disclosure is applicable to the case of mesh model surface reduction of a bound skeleton. The method can be performed by a mesh model surface reduction device, which can be implemented in the form of software and / or hardware, and can be configured in an electronic device, such as a computer.
[0037] As shown in Figure 1 The mesh model surface reduction method provided by the embodiment can include:
[0038] S110, reducing the surface of the original mesh model bound with the skeleton to obtain a first model.
[0039] In the embodiment of the present disclosure, the original mesh model can be considered as a three-dimensional mesh model with high surface number and complex topology. The original mesh model can be bound with the skeleton in advance, and the motion of the original mesh model can be realized by driving the skeleton.
[0040] Among them, the original mesh model can be reduced in surface area based on existing surface reduction algorithms, such as vertex merging, vertex deletion, edge collapse, face collapse and mesh reconstruction algorithms to obtain a surface-reduced mesh model, that is, a first model. Exemplarily, the vertices in the original mesh model can be iteratively merged based on the Quadric Error Metrics (QEM) algorithm to achieve automatic surface reduction of the original mesh model. The QEM algorithm can quickly and accurately perform surface reduction operations on complex meshes with high face counts, effectively reducing the number of vertices while maintaining the overall shape and detailed features of the model to obtain a more streamlined and efficient mesh model. By using the QEM algorithm, the performance and rendering efficiency of the original mesh model can be improved to meet the needs of various application fields for face number optimization.
[0041] S120. Determine a second bone bound to multiple vertices in the first model and a second weight of the second bone based on the first bone bound to multiple vertices in the original mesh model and the first weight of the first bone.
[0042] Among them, the bones bound to the vertices in the original mesh model, and / or the bone weights corresponding to the bound bones may be different. In the embodiment of the present disclosure, the bone bound to the vertex in the original mesh model can be referred to as the first bone of the vertex; and the bone weight corresponding to the first bone can be referred to as the first weight. When a vertex in the original mesh model is bound to at least two first bones, and the first weights of the first bones are not equal, the movement of the vertex will be affected by the at least two first bones, and the greater the first weight, the greater the impact on the movement of the vertex.
[0043] To ensure the model remains drivable after face reduction, after obtaining the first model, the second bones and their second weights bound to multiple vertices in the first model can be determined based on the first bones and their first weights bound to multiple vertices in the original mesh model. The bone bound to a vertex in the first model can be referred to as the second bone of that vertex, and the bone weight corresponding to the second bone can be referred to as the second weight. If a vertex in the first model is bound to at least two second bones, the operation of that vertex is more significantly affected by the second bone with the larger second weight.
[0044] Among them, the process of determining the second bone and its second weight can, for example, include: mapping the vertices in the first model to the vertices in the original mesh model according to the spatial position relationship; and setting the second bone bound to the corresponding vertex in the first model and the second weight of the second bone according to the first bone bound to the mapped vertex and the first weight of the first bone.
[0045] For example, the first model can be aligned with the original mesh model in shape first, and then a first proximity range can be determined with the vertices in the first model as the center and the first predetermined distance value as the radius. Finally, the second bone and the second weight of the corresponding vertex in the first model can be determined according to the first bone and the first weight of the vertex in the original mesh model within the first proximity range. In addition, the bone and the weight of the vertex in the first model can be determined according to the bone and the weight of the vertex in the original mesh model in other manners, which will not be listed here.
[0046] In the embodiments of the present disclosure, by associating the vertices of the first model with the related vertices of the original mesh model and determining the bone and the weight to be bound, the original shape and motion characteristics of the first model can be ensured during the animation driving process, and the drivability and authenticity of the first model can be improved.
[0047] S130, determining the vertices of the demarcation region in the first model according to the second bone and the second weight.
[0048] In the embodiments of the present disclosure, the demarcation region includes a demarcation region between bones of different semantics. It is found through research that the region where the reduced surface mesh model is prone to structural problems during motion is usually located in the demarcation region between bones of different semantics. For example, the number of surface patches in the joint region between bones in the first model is reduced compared with the original mesh model, which may cause the surface patch to protrude out of the model surface when the model is in joint motion, showing an abnormal state of “spike”.
[0049] After determining the second bone and the bone weight of the vertex in the first model, the position of the vertex of the demarcation region in the first model can be further determined according to the second bone and the bone weight of the vertex, so as to locate the region where the first model is prone to structural problems.
[0050] The process of determining the vertices of the demarcation region in the first model may, for example, include: cyclically obtaining the second bone and the second weight bound by the vertex in the first model; determining whether the current vertex is a vertex of the demarcation region according to the currently obtained second bone and second weight; if yes, recording the related information of the vertex of the demarcation region, such as vertex serial number information, position information, bound second bone and second weight, etc.; if not, obtaining the second bone and the second weight bound by the next vertex; until the positions of all vertices in the first model are traversed, the cycle is stopped, and the vertices of each demarcation region in the first model are obtained.
[0051] In the embodiments of the present disclosure, the correspondence between the binding bones and the weights and the vertex categories can be constructed in advance, and then the correspondence can be used to determine whether the vertex bound by the second bone and the second weight is a vertex of the demarcation region. For example, the correspondence between the binding bones and the weights and the vertex categories can be learned by deep learning, and then the second bone and the second weight bound by the vertex can be input into the model after deep learning to determine whether the vertex is a vertex of the demarcation region. For another example, the correspondence between the binding bones and the weights and the vertex categories can be represented by constructing a data formula, and then the data formula can be used to determine whether the vertex is a vertex of the demarcation region. In addition, other ways of constructing the correspondence between the binding bones and the weights and the vertex categories can also be applied herein, which will not be enumerated here.
[0052] In the embodiments of the present disclosure, by identifying the vertices of the demarcation region in the first model, it is beneficial to further take repair measures according to the region to which the vertices of the demarcation region belong, so as to solve the structural problems that may occur in the movement of the first model.
[0053] In S140, a target plane is constructed according to the vertices belonging to the same demarcation region, and an intersection of the target plane and the first model is determined.
[0054] In the embodiments of the present disclosure, the first model can include at least one demarcation region, and for each demarcation region, a target plane can be constructed according to the pre-recorded related information (such as position information, etc.) of the vertices in the region. The target plane obtained by construction can represent the plane where the skeleton turns in the initial mesh model. The first model can be cut by using the target plane to obtain the intersection on the first model. The patch on the first model can have 0, 1 or 2 intersections with the target plane.
[0055] In the embodiments of the present disclosure, the third bone and the third weight bound by the intersection can be determined according to the second bone and the second weight. The bone bound by the intersection can be referred to as the third bone, and the bone weight corresponding to the third bone can be referred to as the third weight. In the case where the intersection is bound by at least two third bones, the movement of the intersection is greatly affected by the third bone with a larger third weight.
[0056] The process of determining the third bone and the third weight bound by the intersection can include: determining a second proximity range with the intersection as the center and a second predetermined distance value as the radius, and determining the third bone and the third weight bound by the intersection according to the second bone and the second weight bound by the vertices in the initial mesh model in the second proximity range. In addition, the bone and the weight bound by the intersection can also be determined based on other ways according to the bones and the weights bound by the vertices in the first model, which will not be enumerated here. By determining the third bone and the third weight bound by the intersection, the correctness of the movement of the model can be ensured.
[0057] S150, dividing the face patch to which the intersection point belongs into at least two sub-face patches to obtain a second model.
[0058] In the embodiments of the present disclosure, the intersection point of the target plane and the first model can be used as a new vertex of the first model, and the intersection point can be used to split the face patch to which the intersection point belongs to achieve the subdivision of at least part of the face patches in the demarcation region of the first model into a plurality of sub-face patches.
[0059] The splitting of the face patch to which the intersection point belongs can be performed based on a preset mathematical algorithm. For example, the intersection point can be connected with a vertex in the face patch to which the intersection point belongs and which does not have a connection relationship, to achieve the generation of a sub-face patch. For example, Figure 2 A schematic diagram of generating a sub-face patch in a mesh model reduction method provided by the embodiments of the present disclosure. Referring to Figure 2 The intersection points of the target plane A and the triangular face patch BCD in the first model can include points a and b, the point a can be connected with the point C to obtain sub-face patches BCa and aCD; then, the point a can be connected with the point b to obtain sub-face patches aCb and abD; and thus the triangular face patch BCD can be split into three sub-face patches BCa, aCb and abD.
[0060] By increasing the number of face patches in the demarcation region, the mesh wiring of the skeleton turning region is enriched, the structural problems such as penetration and spurs in the process of driving the mesh model based on the skeleton after the reduction of the face number can be solved while the low face number of the model is preserved, the structural correctness of the mesh model can be ensured, and the mesh model has better animation performance.
[0061] The technical scheme of the embodiments of the present disclosure reduces the face number of the original mesh model bound with a skeleton to obtain a first model; determines a second skeleton bound with a plurality of vertices in the first model and a second weight of the second skeleton according to a first skeleton bound with the plurality of vertices in the original mesh model and a first weight of the first skeleton; determines a vertex of a demarcation region in the first model according to the second skeleton and the second weight; the demarcation region includes a demarcation region between skeletons with different semantics; constructs a target plane according to the vertices belonging to the same demarcation region, and determines an intersection point of the target plane and the first model; divides the face patch to which the intersection point belongs into at least two sub-face patches to obtain a second model.
[0062] The connection region of different semantic skeletons is a demarcation region with a large deformation amplitude after the model reduction operation. By identifying the vertices in the demarcation region, a target plane is constructed based on the related information of the vertices in the demarcation region, and the target plane can be used to cut the first model to obtain intersection points, which can be used as new boundary points in the model. By generating new facets based on the new boundary points, the grid facets in the region with a large deformation amplitude can be refined, which can solve the structural problems such as penetration and spurs that occur in the skeleton driving process after the reduction, ensure the structural correctness of the grid model, and make the grid model have better animation performance.
[0063] The embodiments of the present disclosure can be combined with the various optional schemes of the mesh model reduction method provided in the above embodiments. The mesh model reduction method provided in the present embodiment describes in detail the determination of the bones and bone weights bound to the plurality of vertices in the first model. By using the nearest neighbor matching method, the first bones and first weights bound to the plurality of vertices in the original mesh model before reduction can be transplanted to each vertex of the first model after reduction, to ensure that the first model after reduction retains the original shape and motion characteristics in the animation driving process, and improves the drivability and authenticity of the model after reduction.
[0064] Figure 3 A flowchart of a mesh model reduction method provided by an embodiment of the present disclosure is shown in FIG. 1. As shown in FIG. 1, the mesh model reduction method provided by the present embodiment can include the following steps. Figure 3
[0065] S310, reducing the original mesh model bound to the bones to obtain a first model.
[0066] S320, determining a preset number of target vertices adjacent to the vertices in the first model from the plurality of vertices of the original mesh model.
[0067] In the present embodiment, the original mesh model and the first model can be aligned in shape. After alignment, for the vertices in the first model, a preset number (N) of target vertices in the original mesh model that are most adjacent to the vertices can be determined. The preset number can be pre-set according to empirical or experimental values.
[0068] S330, determining the second bone bound to the corresponding vertex in the first model and the second weight of the second bone based on the first bone bound to each target vertex and the first weight of the first bone.
[0069] In the present embodiment, N target vertices adjacent to the vertices in the first model can be determined based on the N nearest neighbor algorithm. For each vertex in the first model, the second bone and the second weight of the vertex can be determined according to the first bone bound to the corresponding preset number of target vertices and the first weight.
[0070] In some optional implementations, determining the second bones and the second weights of the corresponding vertex binding in the first model according to the first bones and the first weights of the target vertex binding can include:
[0071] taking the union of the first bones of the target vertex binding as the second bones of the corresponding vertex binding in the first model, and determining the second weights of the second bones of the corresponding vertex binding in the first model according to the distances between the target vertex and the corresponding vertex and the first weights of the first bones of the target vertex binding.
[0072] Since the target vertex is a near neighbor of the vertex in the first model, the target vertices are usually also adjacent to each other. For the same vertex in the first model, the first bones bound by the target vertices are usually the same. At this time, the same at least one first bone bound by the target vertices can be taken as the second bone of the corresponding vertex. The second weight of the second bone can be determined according to the distances between the target vertex and the corresponding vertex, by using an interpolation method or a weighted average method based on the first weights of the first bones bound by the target vertices.
[0073] In addition, there can also be a case where the first bones bound by the target vertices are different. For example, it is assumed that for the vertex A in the first model, the vertex B and the vertex C in the original mesh model are the target vertices thereof. In the case where the first bone bound by the vertex B is bone 1 and bone 2, and the first bone bound by the vertex C is bone 2 and bone 3, the second bone bound by the vertex A can be bone 1, bone 2 and bone 3. On the basis of this example, the weights of bone 1, bone 2 and bone 3 bound by the vertex A can be determined according to the distances between the vertex A and the vertex B and the vertex C, by using a sampling interpolation method or a weighted average method based on the first weights of the first bones bound by the vertex B and the first weights of the first bones bound by the vertex C.
[0074] In these optional implementations, the N-neighbor algorithm can be used to transplant the bones and the weights bound by the plurality of vertices in the original mesh model into the first model, so as to ensure the drivable type and the motion correctness of the first model.
[0075] S340, determining the vertex of the demarcation region in the first model according to the second bones and the second weights.
[0076] The demarcation region includes the vertex of the demarcation region between the bones of different semantics.
[0077] S350, constructing a target plane according to the vertices belonging to the same demarcation region, and determining the intersection point of the target plane and the first model.
[0078] In this embodiment, the third bone bound to the intersection point and the third weight of the third bone are determined according to the second bone and the second weight.
[0079] S360, divide the patch to which the intersection point belongs into at least two sub-patches to obtain the second model.
[0080] The technical solution of the embodiment of the present disclosure has described in detail the determination of the bones bound to the plurality of vertices in the first model and the weights of the bones. By using the near neighbor matching manner, the first bones bound to the plurality of vertices in the original mesh model before the reduction of the surface can be transplanted into each vertex of the first model after the reduction of the surface, so as to ensure that the first model after the reduction of the surface retains the original shape and action characteristics in the process of animation driving, and improve the drivability and authenticity of the model after the reduction of the surface.
[0081] In addition, the mesh model reduction method provided by the embodiment of the present disclosure belongs to the same disclosure concept as the mesh model reduction method provided by the above-mentioned embodiment, and the technical details not described in detail in the present embodiment can be referred to the above-mentioned embodiment, and the same technical features have the same beneficial effects in the present embodiment and the above-mentioned embodiment.
[0082] The mesh model reduction method provided by the embodiment of the present disclosure can be combined with the mesh model reduction method provided in the above-mentioned embodiment. The mesh model reduction method provided by the present embodiment has described in detail the process of determining the vertices of the demarcation region, constructing the target plane, determining the bones bound to the intersection point and the weights of the bones. According to the second bones bound to the plurality of vertices in the first model and the second weights, the vertices of the demarcation region with large deformation amplitude in the motion process can be determined. By clustering the vertices of the demarcation region, the vertices belonging to the same demarcation region can be determined. According to the positions and normal information of the vertices belonging to the same demarcation region, each target plane can be constructed. The cutting of each target plane on the first model can generate new boundary points (i.e. intersection points), and the bones bound to the intersection points and the weights of the bones can be determined according to the bones bound to the plurality of vertices in the patch to which the intersection point belongs and the weights of the bones, so as to ensure the correctness of the motion of the second model.
[0083] Figure 4 The flowchart of the mesh model reduction method provided by the embodiment of the present disclosure is shown in FIG. 1. Figure 4 As shown in FIG. 1, the mesh model reduction method provided by the present embodiment can include the following steps.
[0084] S410, reducing the original mesh model bound to the bone to obtain a first model.
[0085] S420, determining the second bones bound to the plurality of vertices in the first model and the second weights of the second bones according to the first bones bound to the plurality of vertices in the original mesh model and the first weights of the first bones.
[0086] S430, in the case that the bound second skeleton includes at least two, and the second weight of at least two is greater than a preset threshold, the corresponding vertex is determined as the vertex of the boundary region.
[0087] The boundary region includes the vertex of the boundary region between the skeletons with different semantics.
[0088] For example, for the i-th vertex in the first model, assuming that the corresponding second weight is and The second skeleton corresponding to the second weight is In the case that, whether the i-th vertex is the vertex of the boundary region can be determined by the following formula:
[0089]
[0090] Wherein, I(·) can represent an indicator function, when the internal function is correct, that is, 1, I(·) is 1; when the internal function is wrong, that is, 0, I(·) is 0; wherein, Sgn(i) can represent the result of the determination of the vertex of the boundary region, when it is 1, it can be considered that the i-th vertex belongs to the vertex of the boundary region, when it is 0, it can be considered that the i-th vertex does not belong to the vertex of the boundary region; wherein, thres can represent a preset threshold, which can be set according to experimental value or experience value.
[0091] S440, according to the second skeleton bound to the vertex of each boundary region, the vertex belonging to the same boundary region is determined.
[0092] In this embodiment, based on the existing clustering algorithm (such as K-means algorithm), the vertices of each boundary region are clustered according to the second skeleton bound to the vertices of each boundary region, and the vertices of the boundary region of different clusters are obtained. The vertices of each cluster in the boundary region are bound to the same or similar second skeleton, and it can be considered that the vertices in each cluster belong to the same boundary region.
[0093] S451, the center position is determined according to the position of the vertex belonging to the same boundary region.
[0094] In this embodiment, for each boundary region, the position of the center point of the boundary region (i.e. the center position) can be determined based on the position of the vertices inside it using simple average or weighted average and other methods.
[0095] S452, according to the preset corresponding relationship between the skeleton semantics and the normal information, and the semantics of the second skeleton corresponding to the vertex belonging to the same boundary region, the target normal information is determined.
[0096] The original mesh model can be a mesh model in a preset pose. Accordingly, after the face reduction operation, the pose of the initial mesh model is the same as the preset pose. Since the pose of the original mesh model is known in advance, the poses of the corresponding regions of each bone bound to the original mesh model are also known. Therefore, the correspondence between the normal information of each bone and the corresponding region can be pre-set, and this correspondence can be represented as a data pair of bone semantics and normal information.
[0097] Correspondingly, after determining each boundary area, the semantics of the second bone with the largest second weight bound to it can be determined; and from the correspondence between the preset bone semantics and normal information, the normal information of the second bone semantic pair is queried as the target normal information.
[0098] Compared with determining the target normal vector based on the graphic information of the vertices in the boundary area (such as position information), the target normal information can be obtained more quickly through query, thereby improving the generation efficiency of the second model to a certain extent.
[0099] S460: Construct a target plane according to the center position and target normal information, and determine the intersection point between the target plane and the first model.
[0100] In the disclosed embodiment, for each boundary region, an infinite target plane can be constructed based on its corresponding center position and target normal information. Accordingly, the intersection of the target plane and the facet in the first model can be determined.
[0101] Among them, the third bone bound to the intersection and the third weight of the third bone can be determined based on the second bone and the second weight. In some optional implementations, the process of determining the third bone bound to the intersection and the third weight of the third bone can include: determining the third bone corresponding to the intersection and the third weight of the third bone based on the target second bone bound to multiple vertices in the face patch to which the intersection belongs and the second weight of the target second bone.
[0102] In these optional implementations, the patch to which the intersection belongs can be determined based on the coordinate position of the intersection; then the distance between the intersection and each vertex on the patch can be determined; finally, based on each distance, an algorithm such as barycentric interpolation can be used to determine the third bone bound to the intersection and the third weight corresponding to the third bone based on the second bone and second weight bound to multiple vertices on the patch. Among them, barycentric interpolation can be considered as a linear interpolation method based on geometric position, in which the interpolation weight of barycentric interpolation is inversely proportional to the distance, that is, the closer the distance, the greater the interpolation weight, and the farther the distance, the smaller the interpolation weight. The third weight of the intersection can be obtained by taking a weighted average of the second weight of each vertex and the interpolation weight.
[0103] By determining the third bone and the third weight of the intersection point binding based on the second bone and the second weight of the vertex of the face sheet to which the intersection point belongs, the smoothness of the bone weight at the intersection point can be ensured, and structural problems in the motion process can be avoided.
[0104] S470, the face sheet to which the intersection point belongs is divided into at least two sub-face sheets to obtain a second model.
[0105] The technical solutions of the embodiments of the present disclosure are described in detail for determining the vertices of the demarcation region, constructing the target plane, determining the bone and the bone weight of the intersection point binding, etc. By the second bone and the second weight of the plurality of vertices binding in the first model, the vertices of the demarcation region with large deformation amplitude in the motion process can be determined. By clustering the vertices of the demarcation region, the vertices belonging to the same demarcation region can be determined. By the position and normal information of the vertices belonging to the same demarcation region, each target plane can be constructed. The new boundary points (i.e. intersection points) can be generated by cutting the first model with each target plane, and the bone and the bone weight of the intersection point binding can be determined according to the bone and the bone weight of the plurality of vertices binding in the face sheet to which the intersection point belongs, so that the correctness of the motion of the second model can be ensured.
[0106] In addition, the mesh model surface reduction method provided by the embodiments of the present disclosure belongs to the same disclosure concept as the mesh model surface reduction method provided by the above-mentioned embodiments, and the technical details not described in detail in the present embodiment can be referred to the above-mentioned embodiments, and the same technical features have the same beneficial effects in the present embodiment and the above-mentioned embodiments.
[0107] Figure 5 A structural schematic diagram of a mesh model surface reduction device provided by the embodiments of the present disclosure. The mesh model surface reduction device provided by the present embodiment is suitable for the case of reducing the surface of the mesh model binding the bone.
[0108] As Figure 5 shown, the mesh model surface reduction device provided by the embodiments of the present disclosure can include:
[0109] The surface reduction module 510 is configured to reduce the surface of the original mesh model binding the bone to obtain a first model.
[0110] The bone weight transplantation module 520 is configured to determine the second bone and the second weight of the second bone of the plurality of vertices binding in the first model according to the first bone and the first weight of the first bone of the plurality of vertices binding in the original mesh model.
[0111] The vertex determination module 530 is configured to determine the vertices of the demarcation region in the first model according to the second bone and the second weight, wherein the demarcation region includes the demarcation region between the bones with different semantics.
[0112] The intersection determining module 540 is configured to construct a target plane according to the vertices belonging to the same boundary region, and determine the intersection of the target plane and the first model.
[0113] The patch dividing module 550 is configured to divide the patch to which the intersection belongs into at least two sub-patches, to obtain the second model.
[0114] In some optional implementations, the skeleton weight transplanting module can be configured to:
[0115] determine, from the plurality of vertices of the original mesh model, a preset number of target vertices adjacent to the vertex in the first model;
[0116] determine, according to the first skeleton to which each target vertex is bound and the first weight of the first skeleton, the second skeleton to which the corresponding vertex in the first model is bound and the second weight of the second skeleton.
[0117] In some optional implementations, the skeleton weight transplanting module can be configured to:
[0118] take the union of the first skeletons to which each target vertex is bound as the second skeleton to which the corresponding vertex in the first model is bound;
[0119] determine, according to the distance between each target vertex and the corresponding vertex in the first model and the first weight of the first skeleton to which each target vertex is bound, the second weight of the second skeleton to which the corresponding vertex in the first model is bound.
[0120] In some optional implementations, the vertex determining module can be configured to:
[0121] in a case where the bound second skeleton includes at least two and the at least two second weights are greater than a preset threshold, determine the corresponding vertex as a vertex of a boundary region.
[0122] In some optional implementations, the mesh model reducing device can further include:
[0123] The clustering module is configured to, after determining the vertices of the boundary regions in the first model, determine the vertices belonging to the same boundary region according to the second skeleton to which each vertex of the boundary region is bound.
[0124] In some optional implementations, the intersection determining module can be configured to:
[0125] determine a center position according to the positions of the vertices belonging to the same boundary region;
[0126] determine the target normal information according to a preset correspondence between a skeleton semantic and normal information and the semantic of the second skeleton corresponding to the vertices belonging to the same boundary region;
[0127] The target plane is constructed according to the center position and the target normal information.
[0128] In some optional implementations, the skeleton weight transplantation module can be further configured to:
[0129] The third skeleton and the third weight of the corresponding intersection point are determined according to the target second skeleton and the second weight of the target second skeleton bound by a plurality of vertices in the face sheet to which the intersection point belongs.
[0130] The mesh model reducing device provided by the embodiments of the present disclosure can execute the mesh model reducing method provided by any of the embodiments of the present disclosure, and has the corresponding function modules and beneficial effects of the execution method. It should be noted that each unit and module included in the above device is only divided according to the function logic, but is not limited to the above division, as long as the corresponding function can be implemented; in addition, the specific name of each functional unit is only for easy mutual distinction, and does not limit the protection scope of the embodiments of the present disclosure.
[0131] Reference will be made to the following description Figure 6 , which shows a structural schematic diagram of an electronic device (for example, a terminal device or a server in Figure 6 ) 600 suitable for implementing the embodiments of the present disclosure. The terminal device in the embodiments of the present disclosure can include but is not limited to mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Tablet Personal Computers), PMPs (Portable Multimedia Players), vehicle-mounted terminals (for example, vehicle-mounted navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like. Figure 6 The electronic device shown is only an example, and should not bring any limitation to the functions and use range of the embodiments of the present disclosure.
[0132] As shown in Figure 6 , the electronic device 600 can include a processing device (for example, a central processor, a graphics processor, and the like) 601, which can perform various appropriate actions and processes according to programs stored in a read-only memory (Read-Only Memory, ROM) 602 or loaded from a storage device 608 to a random access memory (Random Access Memory, RAM) 603. In the RAM 603, various programs and data required for the operation of the electronic device 600 are also stored. The processing device 601, the ROM 602, and the RAM 603 are connected to each other through a bus 604. An input / output (I / O) interface 605 is also connected to the bus 604.
[0133] In general, the following devices can be connected to the I / O interface 605: input devices 606 including, for example, a touch screen, a touch pad, a keyboard, a mouse, a camera, a microphone, an accelerometer, a gyroscope, and the like; output devices 607 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, and the like; storage devices 608 including, for example, a magnetic tape, a hard disk, and the like; and communication devices 609. The communication devices 609 can allow the electronic device 600 to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 The electronic device 600 is shown with various devices, but it is understood that all of the illustrated devices are not required to implement or be present. More or fewer devices can alternatively be implemented or present.
[0134] In particular, according to embodiments of the present disclosure, the processes described above with reference to the flowcharts can be implemented as a computer software program. For example, embodiments of the present disclosure include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for executing the methods illustrated by the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network through the communication devices 609, or installed from the storage devices 608, or installed from the ROM 602. When the computer program is executed by the processing devices 601, the above-mentioned functions defined in the mesh model surface reduction method of embodiments of the present disclosure are performed.
[0135] The electronic device provided by embodiments of the present disclosure and the mesh model surface reduction method provided by the above-mentioned embodiments belong to the same disclosure concept, and technical details not described in detail in the present embodiment can be referred to the above-mentioned embodiments, and the present embodiment has the same beneficial effects as the above-mentioned embodiments.
[0136] Embodiments of the present disclosure provide a computer storage medium having a computer program stored thereon, which, when executed by a processor, implements the mesh model surface reduction method provided by the above-mentioned embodiments.
[0137] It should be noted that the computer-readable medium described above can be a computer-readable signal medium or a computer-readable storage medium or any combination thereof. The computer-readable storage medium, for example, can be, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program used by or in connection with an instruction execution system, apparatus or device. In the present disclosure, the computer-readable signal medium can include a data signal propagated in baseband or propagated as a carrier wave in a propagated data signal, in which the computer-readable program code is contained. Such a propagated data signal can take any of a variety of forms, including, but not limited to, an electromagnetic signal, an optical signal, or any suitable combination of the foregoing. The computer-readable signal medium can also be any computer-readable medium that is not a storage medium and that can communicate, propagate or transport a program for use by or in connection with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including, but not limited to, wire, cable, RF (radio frequency), or the like, or any suitable combination of the foregoing.
[0138] In some embodiments, the client, server, or both can communicate using any current known or future developed network protocol, such as HTTP (Hyper Text Transfer Protocol), and can be interconnected with any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include local area networks ("LAN"), wide area networks ("WAN"), the Internet, and peer-to-peer networks (e.g., ad hoc peer-to-peer networks), as well as any current known or future developed networks.
[0139] The computer-readable medium described above can be included in the electronic device described above; or can exist separately from the electronic device described above, and can be accessed via the electronic device described above.
[0140] The computer-readable medium described above carries one or more programs, when the one or more programs are executed by the electronic device, cause the electronic device to:
[0141] The original mesh model of the bound skeleton is decimated to obtain a first model; a first bone and a second bone to which a plurality of vertices in the first model are bound and a second weight of the second bone are determined according to a first weight of the first bone and the first bone to which the plurality of vertices in the original mesh model are bound; a vertex of a demarcation region in the first model is determined according to the second bone and the second weight; wherein the demarcation region includes a demarcation region between bones of different semantics; a target plane is constructed according to the vertices belonging to the same demarcation region, and an intersection of the target plane and the first model is determined; a face sheet to which the intersection belongs is divided into at least two sub-face sheets to obtain a second model.
[0142] Computer program code for carrying out operations of the present disclosure can be written in one or more programming languages or combinations of languages including object oriented programming languages such as Java, Smalltalk, C++ or conventional procedural programming languages such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0143] The flow and block diagrams in the drawings show architectural, functional, and operational aspects of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flow and block diagrams can represent a module, a segment, or a portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently or the blocks may
[0144] The units described in the embodiments of the present disclosure can be implemented by software, or by hardware. In some cases, the names of the units and modules do not constitute a limitation on the units and modules themselves.
[0145] The functionality described above in this document can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, exemplary types of hardware logic components that can be used include Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standard Parts (ASSPs), System on Chips (SOCs), Complex Programmable Logic Devices (CPLDs), etc.
[0146] In the context of this disclosure, a machine-readable medium can be a tangible medium that contains or stores a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the machine-readable storage medium will include one or more lines of electrical connections, portable computer disks, hard disk drives, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or Flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.
[0147] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, which comprises:
[0148] Decimating the original mesh model of the bound skeleton to obtain a first model;
[0149] According to the first bone bound to the plurality of vertices in the original mesh model and the first weight of the first bone, determining a second bone bound to the plurality of vertices in the first model and a second weight of the second bone;
[0150] According to the second bone and the second weight, determining a vertex of a demarcation region in the first model; wherein the demarcation region comprises a demarcation region between bones of different semantics;
[0151] Constructing a target plane according to the vertices belonging to the same demarcation region, and determining an intersection point of the target plane and the first model;
[0152] Divide the patch to which the intersection belongs into at least two sub-patches to obtain a second model.
[0153] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0154] In some optional implementations, the determination of the second skeleton and the second weight comprises:
[0155] Determining, from the plurality of vertices of the original mesh model, a preset number of target vertices adjacent to the vertices in the first model;
[0156] Determining, according to the first skeleton bound to each of the target vertices and the first weight of the first skeleton, a second skeleton bound to the corresponding vertices in the first model and a second weight of the second skeleton.
[0157] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0158] In some optional implementations, the determination of the second skeleton bound to the corresponding vertices in the first model and the second weight of the second skeleton according to the first skeleton bound to each of the target vertices and the first weight of the first skeleton comprises:
[0159] Taking the union set of the first skeleton bound to each of the target vertices as the second skeleton bound to the corresponding vertices in the first model;
[0160] Determining, according to the distance between each of the target vertices and the corresponding vertices in the first model and the first weight of the first skeleton bound to each of the target vertices, the second weight of the second skeleton bound to the corresponding vertices in the first model.
[0161] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0162] In some optional implementations,
[0163] The determination of the vertices of the demarcation region in the first model according to the second skeleton and the second weight comprises:
[0164] In a case where the bound second skeleton comprises at least two and at least two second weights are greater than a preset threshold, the corresponding vertices are determined as the vertices of the demarcation region.
[0165] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0166] In some optional implementations, after the determination of the vertices of the demarcation region in the first model, the method further comprises:
[0167] determine vertices belonging to the same boundary region according to the second bone bound to the vertices of each boundary region.
[0168] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0169] In some optional implementations, the target plane is constructed according to the vertices belonging to the same boundary region, comprising:
[0170] determine a center position according to the positions of the vertices belonging to the same boundary region;
[0171] determine target normal information according to a preset correspondence between bone semantics and normal information, and the semantics of the second bone corresponding to the vertices belonging to the same boundary region;
[0172] construct a target plane according to the center position and the target normal information.
[0173] According to one or more embodiments of the present disclosure, a mesh model decimation method is provided, further comprising:
[0174] In some optional implementations, the third bone bound to the intersection point and the third weight of the third bone are determined, comprising:
[0175] determine a third bone corresponding to the intersection point and a third weight of the third bone according to a target second bone bound to a plurality of vertices in a patch to which the intersection point belongs and a second weight of the target second bone.
[0176] According to one or more embodiments of the present disclosure, a mesh model decimation device is provided, comprising:
[0177] a decimation module configured to decimate an original mesh model bound to a bone to obtain a first model;
[0178] a bone weight transplantation module configured to determine a second bone bound to a plurality of vertices in the first model and a second weight of the second bone according to a first bone bound to the plurality of vertices in the original mesh model and a first weight of the first bone;
[0179] a vertex determination module configured to determine vertices of a boundary region in the first model according to the second bone and the second weight; wherein the boundary region comprises a boundary region between bones of different semantics;
[0180] an intersection point determination module configured to construct a target plane according to the vertices belonging to the same boundary region, and determine an intersection point of the target plane and the first model;
[0181] The face patch division module is configured to divide the face patch to which the intersection belongs into at least two sub-face patches, to obtain a second model.
[0182] The above description is merely that of the preferred embodiments of the present disclosure and the principles of the technology employed, and the scope of the disclosure involved is not limited to the technical solutions formed by the specific combinations of the technical features described above. It should also be understood that other technical solutions formed by the combinations of the technical features described above or their equivalent features, without departing from the above disclosed concepts, should also be encompassed in the scope of the disclosure. For example, the technical solutions formed by the mutual replacement of the above described features and the technical features with similar functions disclosed in the present disclosure (but not limited to) should also be encompassed.
[0183] Furthermore, although each operation is depicted in a particular, sequential order, this should not be understood as requiring such order unless specifically specified that an order is "critical." One of ordinary skill in the art will also understand that a plurality of operations can be performed at the same time. It will also be understood that certain features that are, for clarity, described above as taking place in separate blocks, can be performed by the same equipment, e.g., a processor or digital signal processor. Likewise, functions illustrated to be performed by separate equipment or circuitry can be performed by the same equipment, e.g., an analog to digital converter or digital to analog converter. Although the present subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
[0184] While the subject matter has been described above in the general context of structural features and / or method logical steps, it should be understood that the subject defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims. Those skilled in the art will appreciate that the functionality of the subject can be achieved by any number of means, and is not limited to the specific features or acts described above.
Claims
1. A method for reducing the surface of a mesh model, characterized in that: include: Reduce the original mesh model of the bound skeleton to obtain the first model; Determining a second bone bound to a plurality of vertices in the first model and a second weight of the second bone based on a first bone bound to a plurality of vertices in the original mesh model and a first weight of the first bone; Determining vertices of a boundary region in the first model according to the second skeleton and the second weight; wherein the boundary region includes boundary regions between skeletons of different semantics; constructing a target plane based on vertices belonging to the same boundary area, and determining an intersection point between the target plane and the first model; The patch to which the intersection point belongs is divided into at least two sub-patches to obtain a second model.
2. The method according to claim 1, characterized in that The process of determining the second skeleton and the second weight includes: Determining a preset number of target vertices adjacent to vertices in the first model from a plurality of vertices in the original mesh model; According to the first bone bound to each target vertex and the first weight of the first bone, the second bone bound to the corresponding vertex in the first model and the second weight of the second bone are determined.
3. The method according to claim 2, characterized in that The determining, based on the first bone bound to each target vertex and the first weight of the first bone, the second bone bound to the corresponding vertex in the first model and the second weight of the second bone, includes: The union of the first bones bound to each of the target vertices is used as the second bone bound to the corresponding vertex in the first model; The second weight of the second bone bound to the corresponding vertex in the first model is determined based on the distance between each target vertex and the corresponding vertex in the first model, and the first weight of the first bone bound to each target vertex.
4. The method according to claim 1, wherein The step of determining the vertices of the boundary area in the first model according to the second skeleton and the second weight includes: When the bound second bones include at least two and at least two second weights are greater than a preset threshold, the corresponding vertices are determined as vertices of the boundary area.
5. The method according to claim 1, wherein After determining the vertices of the boundary area in the first model, the method further includes: According to the second skeleton bound to the vertices of each boundary area, the vertices belonging to the same boundary area are determined.
6. The method according to claim 1, wherein The step of constructing a target plane based on vertices belonging to the same boundary region includes: Determine the center position based on the positions of the vertices belonging to the same boundary area; Determine the target normal information based on the correspondence between the preset bone semantics and the normal information, and the semantics of the second bone corresponding to the vertices belonging to the same boundary area; A target plane is constructed according to the center position and the target normal information.
7. The method according to claim 1, characterized in that The process of determining the third bone bound to the intersection and the third weight of the third bone includes: According to the target second bone bound to multiple vertices in the face patch to which the intersection belongs and the second weight of the target second bone, the third bone corresponding to the intersection and the third weight of the third bone are determined.
8. A surface reduction device for a mesh model, characterized in that: include: A face reduction module, used for reducing the faces of the original mesh model with bound bones to obtain a first model; a bone weight transplantation module, configured to determine a second bone bound to a plurality of vertices in the first model and a second weight of the second bone based on a first bone bound to a plurality of vertices in the original mesh model and a first weight of the first bone; a vertex determination module, configured to determine vertices of a boundary region in the first model according to the second skeleton and the second weight; wherein the boundary region includes a boundary region between skeletons of different semantics; an intersection determination module, configured to construct a target plane based on vertices belonging to the same boundary area, and determine an intersection point between the target plane and the first model; The patch division module is used to divide the patch to which the intersection point belongs into at least two sub-patches to obtain a second model.
9. An electronic device, characterized in that: The electronic device comprises: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the mesh model surface reduction method as described in any one of claims 1 to 7.
10. A storage medium comprising computer executable instructions, wherein the computer executable instructions are used to perform the mesh model surface reduction method according to any one of claims 1 to 7 when executed by a computer processor.