CN112785689A

CN112785689A - Three-dimensional model construction method, device and system and storage medium

Info

Publication number: CN112785689A
Application number: CN202110119009.4A
Authority: CN
Inventors: 刘思阳
Original assignee: Beijing IQIYI Science and Technology Co Ltd
Current assignee: Beijing IQIYI Science and Technology Co Ltd
Priority date: 2021-01-28
Filing date: 2021-01-28
Publication date: 2021-05-11

Abstract

The embodiment of the invention provides a method, a device and a system for building a three-dimensional model and a storage medium. The construction method comprises the following steps: acquiring grid information and skeleton information of a head and a trunk of a human body three-dimensional model; determining head key points and trunk key points according to the grid information and the skeleton information; constructing a head proxy according to the head key points, and constructing a trunk proxy according to the trunk key points; and replacing the head and the trunk of the human body three-dimensional model by the head agent body and the trunk agent body to obtain the simplified human body three-dimensional model.

Description

Three-dimensional model construction method, device and system and storage medium

Technical Field

The invention relates to the technical field of three-dimensional models, in particular to a method, a device and a system for constructing a three-dimensional model and a storage medium.

Background

The 3D virtual character has a plurality of applications in animation and movie special effects, and the general flow is to capture various motions of actors through motion capture technology and then transfer the motions to a specified 3D model.

However, there are many problems in the migration process, such as that the actor and the 3D model to be driven have different sizes, so that the 3D model makes some actions that do not conform to the physical principle, such as extending the handle into the model.

Disclosure of Invention

In order to solve the problems in the prior art, at least one embodiment of the present invention provides a method, an apparatus, a system, and a storage medium for building a three-dimensional model.

In a first aspect, an embodiment of the present invention provides a three-dimensional model building method, where the building method includes:

acquiring grid information and skeleton information of a head and a trunk of a human body three-dimensional model;

determining head key points and trunk key points according to the grid information and the skeleton information;

constructing a head proxy according to the head key points, and constructing a trunk proxy according to the trunk key points;

and replacing the head and the trunk of the human body three-dimensional model by the head agent body and the trunk agent body to obtain the simplified human body three-dimensional model.

Based on the above technical solutions, the embodiments of the present invention may be further improved as follows.

With reference to the first aspect, in a first embodiment of the first aspect, the head keypoints comprise: eyes, nose tip, mouth horn, chin tip, ears, vertex, head circumference and back head scoop.

With reference to the first embodiment of the first aspect, in a second embodiment of the first aspect, the method for determining grid points corresponding to a head circumference includes:

acquiring three-dimensional information of neck joint points according to the bone information of the head;

taking the mean value of the coordinates of the grid points corresponding to the vertex of the head and the tip of the nose in the vertical direction as the coordinates of the head circumference in the vertical direction;

determining neck projection points and nose tip projection points of grid points corresponding to the neck joint points and the nose tips on a cross section of the head circumference in the horizontal direction according to the three-dimensional information of the neck joint points and the grid information of the grid points corresponding to the nose tips;

taking the neck projection point as an origin, and generating four rays on the section of the head circumference in the horizontal direction; the four rays divide the cross section of the head circumference in the horizontal direction into four equal parts, and the connecting line of the neck projection point and the nose tip projection point divides an included angle formed by two rays adjacent to the nose tip projection point into two equal parts;

taking the grid point closest to the head circumference intersection point as the grid point corresponding to the head circumference according to the grid information of the head; wherein the head circumference intersection point is an intersection point of the ray and the grid structure of the head.

With reference to the first embodiment of the first aspect, in a third embodiment of the first aspect, the method for determining grid points corresponding to the hindbrain scoop includes:

determining neck projection points of the neck joint points on a section of the horizontal direction where grid points corresponding to the nose tip are located according to the three-dimensional information of the neck joint points;

taking the grid point closest to the point of intersection with the hindbrain scoop as the grid point corresponding to the hindbrain scoop according to the grid information of the head; the back head and the back head intersection point are the intersection points of the extension line of the connecting line of the grid point corresponding to the nose tip and the neck projection point and the grid structure of the head.

With reference to the first embodiment of the first aspect, in a fourth embodiment of the first aspect, the method for determining torso keypoints comprises:

determining three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point and three-dimensional information of a second spine joint point according to the skeleton information of the trunk;

determining the mean value of the coordinates of the left shoulder joint point and the right shoulder joint point in the vertical direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, wherein the mean value is used as the coordinate of the trunk key point in the vertical direction;

determining a second spine projection point and a nose tip projection point of the grid point corresponding to the second spine joint point and the nose tip on the section of the horizontal direction where the trunk key point is located according to the three-dimensional information of the second spine joint point and the grid information of the grid point corresponding to the nose tip;

determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on a section of the trunk key point in the horizontal direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point;

establishing a first ray from the second spine projection point to the nose tip projection point according to the second spine projection point and the nose tip projection point by taking the second spine projection point as a starting point;

taking a grid point closest to the trunk intersection point as the trunk key point according to the grid information of the trunk; the trunk intersection point is an intersection point of a second ray constructed by taking the left shoulder projection point as a starting point and the grid structure of the trunk, the trunk intersection point is an intersection point of a third ray constructed by taking the right shoulder projection point as a starting point and the grid structure of the trunk, and the directions of the first ray, the second ray and the third ray are the same.

With reference to the first embodiment of the first aspect, in a fifth embodiment of the first aspect, the method for determining torso keypoints comprises:

according to the skeleton information of the trunk, determining three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point, three-dimensional information of a first spine joint point and three-dimensional information of a second spine joint point; wherein the coordinate of the first spinal joint point in the vertical direction is greater than the coordinate of the second spinal joint point in the vertical direction;

establishing a section in the horizontal direction of the first spinal joint point as a spinal reference section;

determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on the spine reference section according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point;

establishing a connecting line for connecting the left shoulder projection point and the right shoulder projection point, wherein the connecting line is used as a reference connecting line;

establishing a perpendicular line by taking the first spine joint point as a vertical center, and dividing the spine reference section into a first reference section and a second reference section; wherein the perpendicular line is perpendicular to the reference line;

vertically moving the first reference cross section and the second reference cross section downwards to the second spinal joint point, and acquiring the distance between each grid point in the first reference cross section and the reference connecting line in real time and the distance between each grid point in the second reference cross section and the reference connecting line in real time according to the grid information of the trunk;

and taking the grid point with the maximum distance from the reference connecting line in the first reference section and the grid point with the maximum distance from the reference connecting line in the second reference section as the key points of the trunk.

With reference to the first embodiment of the first aspect, in a sixth embodiment of the first aspect, the method for determining torso keypoints comprises:

determining three-dimensional information of hip joint points and three-dimensional information of first spine joint points according to the skeleton information of the trunk;

determining a first spine projection point and a nose tip projection point of the grid points corresponding to the first spine joint point and the nose tip on the section of the hip joint point in the horizontal direction according to the three-dimensional information of the first spine joint point and the grid information of the grid points corresponding to the nose tip;

generating three rays on a cross section of the hip joint point in the horizontal direction by taking the first spine projection point as an origin; the cross section of the hip joint point in the horizontal direction is divided into three equal parts by the three rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the first spine projection point and the nose tip projection point;

taking the grid point closest to the intersection point of the hip as a trunk key point according to the grid information of the trunk; wherein the buttock intersection point is an intersection point of the ray and the mesh structure of the trunk.

With reference to the first embodiment of the first aspect, in a seventh embodiment of the first aspect, the method for determining torso keypoints comprises:

determining three-dimensional information of a left hip joint point and three-dimensional information of a right hip joint point according to the skeleton information of the trunk;

determining the mean value of the coordinates of the left crotch bone joint point and the right crotch bone joint point in the vertical direction according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point, and taking the mean value as the coordinates of the trunk key point in the vertical direction;

establishing a horizontal section at the key point of the trunk as a crotch bone reference section;

determining a left crotch bone projection point and a right crotch bone projection point of the left crotch bone joint point and the left crotch bone joint point on the crotch bone reference section;

establishing a first ray and a second ray on the crotch bone reference section by taking the left crotch bone projection point as a starting point; wherein a connecting line between the projection point of the left crotch bone and the right crotch bone bisects an included angle formed by the first ray and the second ray;

establishing a third ray and a fourth ray on the crotch bone reference section by taking the right crotch bone projection point as a starting point; wherein a connecting line between the projection point of the left crotch bone and the right crotch bone bisects an included angle formed by the third ray and the fourth ray;

taking a grid point closest to a crotch bone intersection point as a trunk key point according to the grid information of the trunk; and the crotch bone intersection point is the intersection point of the first ray, the second ray, the third ray and the fourth ray with the grid structure of the trunk respectively.

With reference to the first aspect or the first, second, third, fourth, fifth, sixth or seventh embodiment of the first aspect, in an eighth embodiment of the first aspect, the constructing a head proxy according to the head keypoints and constructing a torso proxy according to the torso keypoints includes:

connecting every two head key points to obtain a first grid structure;

removing the connecting line inside the first grid structure to obtain a head grid structure as the head agent;

connecting the trunk key points pairwise to obtain a second grid structure;

and removing the connecting line inside the second grid structure to obtain a trunk grid structure as the trunk agent.

In a second aspect, an embodiment of the present invention provides a three-dimensional model building apparatus, where the building apparatus includes:

the first processing unit is used for acquiring the grid information and skeleton information of the head and the trunk of the human body three-dimensional model;

the second processing unit is used for determining head key points and the trunk key points according to the grid information and the skeleton information;

the third processing unit is used for constructing a head proxy according to the head key points and constructing a body proxy according to the body key points;

and the fourth processing unit is used for replacing the head and the trunk of the human body three-dimensional model by the head agent body and the trunk agent body to obtain the simplified human body three-dimensional model.

In a third aspect, an embodiment of the present invention provides a three-dimensional model building system, including a processor, a communication interface, a memory, and a communication bus, where the processor and the communication interface complete communication between the memory and the processor through the communication bus;

a memory for storing a computer program;

and a processor configured to implement the three-dimensional model construction method according to any one of the embodiments of the first aspect when executing the program stored in the memory.

In a fourth aspect, the present invention provides a computer-readable storage medium, where one or more programs are stored, and the one or more programs are executable by one or more processors to implement the three-dimensional model building method according to any one of the first aspects.

Compared with the prior art, the technical scheme of the invention has the following advantages: the embodiment of the invention realizes the simplification of the human body three-dimensional model by acquiring the grid information and the skeleton information of the head and the trunk of the human body three-dimensional model, determining the key points of the head and the trunk according to the grid information and the skeleton information, constructing the proxy bodies corresponding to the head and the trunk according to the key points of the head and the trunk, and replacing the corresponding parts in the human body three-dimensional model by the proxy bodies, and completes the algorithms of motion redirection, collision operation, die-through repair and the like of a low-precision scene through the simplified human body three-dimensional model, thereby avoiding the operation detection by the original human body three-dimensional model and further improving the operation efficiency.

Drawings

FIG. 1 is a schematic diagram of a system provided in accordance with various embodiments of the present invention;

FIG. 2 is a schematic flow chart of a method provided by an embodiment of the present invention;

FIG. 3 is a schematic flow chart of a method provided by another embodiment of the present invention;

FIG. 4 is a schematic flow chart of a method according to another embodiment of the present invention;

FIG. 5 is a second flowchart of a method according to another embodiment of the present invention;

FIG. 6 is a third flowchart of a method according to another embodiment of the present invention;

FIG. 7 is a third flowchart of a method according to another embodiment of the present invention;

FIG. 8 is a third flowchart of a method according to another embodiment of the present invention;

FIG. 9 is a third flowchart of a method according to another embodiment of the present invention;

FIG. 10 is a schematic structural diagram of an apparatus according to yet another embodiment of the present invention;

fig. 11 is a schematic structural diagram of a system according to another embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1, to implement the structural schematic diagram of a system according to various embodiments of the present invention, the system includes a terminal, where the terminal includes: a processor 1110 and a memory 1130, wherein the terminal may be a mobile terminal such as a mobile phone, a tablet computer, a notebook computer, a palmtop computer, a Personal Digital Assistant (PDA), a Portable Media Player (PMP), a navigation device, a wearable device, a smart band, a pedometer, and a fixed terminal such as a digital TV, a desktop computer, and the like.

As shown in fig. 2, a three-dimensional model building method according to an embodiment of the present invention is provided. Referring to fig. 2, the construction method includes the steps of:

and S11, acquiring the grid information and skeleton information of the head and the trunk of the human body three-dimensional model.

In the present embodiment, three-dimensional human body modeling, which is a component of computer human body simulation, has been one of the hot spots of research. Since the birth of interactive computer graphics, learners have continuously explored computer human body modeling techniques. Significant progress has been made in the evolution of wire-frame modeling, solid modeling, surface modeling to physics-based modeling.

In this embodiment, with the development of 3D games and virtual reality technologies, the requirement for the simulation degree of objects in a scene is higher and higher, and the requirement for a three-dimensional model is accordingly improved, wherein the three-dimensional model of a human body is generally controlled by a user, the user completes complex actions in the scene by controlling the three-dimensional model of the human body, the requirement for the three-dimensional model of the human body is higher and higher, once the three-dimensional model of the human body fails to restore actions or the limbs of the three-dimensional model of the human body overlap, which is referred to as "mold penetration" in the industry, the use experience of the user is seriously affected, and therefore, after the three-dimensional model of the human body is built, the motion process of the three-dimensional model of the human body is verified according to the operational logic of the three-dimensional model of the human body, and it is determined whether the three-dimensional, because the complete three-dimensional model of the human body is relatively fine and complex, the system calculation amount for controlling the motion of the three-dimensional model of the human body is very time-consuming.

In this embodiment, the human three-dimensional model includes a static three-dimensional digital human body used in current animation and games in the industry, and the number of faces of the mesh determines the fineness of the model itself mainly through a 3D mesh model (generally called mesh). In the game, because the performance of a computer is greatly consumed by rendering a large number of grids in real time, the number of grids in the actual game is not too high, and a model with a lower number of surfaces is actually used and then pasted with a map, so that a user can look very real.

In this embodiment, the mesh of the general human body surface is formed by triangular mesh to form the smallest plane, and the smaller the distance between the mesh points forming the mesh is, the smaller the mesh is, and the higher the accuracy of the model to be formed is, and in this step, the mesh information of the head and the torso, that is, the information of each mesh point of the head and the torso of the human body, for example, the position information of the mesh points, is acquired.

In the present embodiment, the mesh information refers to position information of respective mesh points of the head and the torso constituting the three-dimensional model of the human body.

In this embodiment, in the existing project using a three-dimensional human body model, when a simulation motion of the three-dimensional human body model is performed, in order to improve the simulation effect of the three-dimensional human body model, a human skeleton 3D model is constructed for the three-dimensional human body model, and when the motion of the three-dimensional human body model is further determined through the human skeleton 3D model, the motion situation of the grid points on the model surface is determined according to the motion situation of the skeleton, so as to improve the motion control precision of the three-dimensional human body model.

In the present embodiment, the skeleton information is skeleton point position information of the head and the trunk constituting the three-dimensional model of the human body.

In this embodiment, after the mesh information of the head and the trunk of the three-dimensional human model is obtained, the skeleton information of the head and the trunk of the three-dimensional human model is obtained, and the skeleton information of the head and the trunk of the three-dimensional human model can be obtained through the 3D human skeleton model.

And S12, determining head key points and trunk key points according to the grid information and the skeleton information.

In the embodiment, the key points of the head and the trunk are determined according to the grid information and the skeleton information of the head and the trunk; since the three-dimensional model needs to be simplified, in this step, the head key points and the torso key points may be points where the shapes of the head and the torso are relatively prominent, and in order to ensure that the simplified three-dimensional model can complete collision detection or through mold detection, the points corresponding to the relatively important regions may be reserved in addition to the contour points on the head, for example, the head key points may include: eyes, nose tip, mouth corner, chin tip, ears, vertex, head circumference and back head, and the trunk key points can be determined synchronously according to the skeleton information and the mesh information, for example, the trunk key points can include: however, since the three-dimensional models are different in simplicity, it is also possible to reduce the amount of calculation by identifying the accurate position and then using the mesh point closest to the position as the corresponding key point.

And S13, constructing a head proxy according to the head key points, and constructing a trunk proxy according to the trunk key points.

In the embodiment, a corresponding head proxy and a corresponding body proxy are respectively constructed according to the head key points and the body key points; for example, a head agent is constructed according to the head key points, triangular meshes can be constructed according to the head key points to form the head agent, it is ensured that no head key point is located inside the head agent, or any triangular mesh is not located inside the head agent, the construction of the head agent is completed, and similarly, the construction of the trunk agent can be completed.

In this embodiment, since the head key points and the trunk key points are partial points in the original three-dimensional model of the human body, the agent body constructed by the head key points and the trunk key points is more simplified than the original three-dimensional model, but since the simplified model needs to be able to complete the algorithms of motion redirection, collision operation, die-piercing repair, and the like of the original three-dimensional model of the human body, once the selected key points are deviated, the finally simplified agent body cannot replace the original three-dimensional model, and the problem can not be detected by the agent body.

And S14, replacing the head and the trunk of the human body three-dimensional model by the head agent body and the trunk agent body to obtain the simplified human body three-dimensional model.

In this embodiment, the head key points and the trunk key points are extracted according to the mesh information and the skeleton information of the original model, and the agent bodies are constructed corresponding to the head key points and the trunk key points, so that the agent bodies are used for realizing the agent of the human body three-dimensional model, and the simplified human body three-dimensional model is obtained.

In the embodiment, the mesh information and the skeleton information of the head and the trunk of the human body three-dimensional model are obtained, the key points of the head and the key points of the trunk are determined according to the mesh information and the skeleton information, the agent bodies corresponding to the head and the trunk are constructed according to the key points of the head and the key points of the trunk, and the corresponding parts in the human body three-dimensional model are replaced by the agent bodies, so that the human body three-dimensional model is simplified, algorithms such as motion redirection, collision operation, die-piercing repair and the like of a low-precision scene are completed through the simplified human body three-dimensional model, the operation detection with the original human body three-dimensional model is avoided, and the operation efficiency is improved.

As shown in fig. 3, in this embodiment, in S14, the method for constructing a head proxy according to the head keypoints and constructing a body proxy according to the body keypoints includes the following steps:

and S21, connecting every two head key points to obtain a first grid structure.

And S22, removing the connecting lines in the first grid structure to obtain the head grid structure as the head agent.

In this embodiment, in order to accelerate the construction of the head proxy, in this scheme, the head key points are connected in pairs, so that a mesh structure with connecting lines inside is finally obtained, at this time, all the connecting lines in the mesh structure are removed, and a proxy body composed of triangular meshes similar to the original human body three-dimensional model can be obtained.

And S23, connecting the key points of the trunk pairwise to obtain a second grid structure.

And S24, removing the connecting lines inside the second grid structure to obtain the trunk grid structure as a trunk agent.

In this embodiment, in order to accelerate the construction of the trunk proxy body, the trunk key points are connected in pairs in the scheme, so that a mesh structure with connecting lines inside is finally obtained, at this time, all the connecting lines in the mesh structure are removed, and a proxy body composed of triangular meshes similar to the original three-dimensional model of the human body can be obtained.

Compared with the construction method provided by the embodiment, the method for constructing the three-dimensional model provided by the embodiment of the invention is different from the method for constructing the three-dimensional model provided by the embodiment of the invention in that the method for determining the grid points corresponding to the head circumference is provided.

As shown in fig. 4, specifically, in this embodiment, the method for determining grid points corresponding to a head circumference includes the following steps:

and S31, acquiring three-dimensional information of the neck joint point according to the bone information of the head.

In this embodiment, the three-dimensional system is a space system formed by adding a direction vector to a planar two-dimensional system. Three dimensions are three axes of coordinate axes, namely x axis, y axis and z axis, wherein x represents left and right space, y represents front and back space, and z represents up and down space (a rectangular plane coordinate system cannot be used for understanding the space direction).

In the present embodiment, the three-dimensional information refers to three-dimensional position information.

In the present embodiment, three-dimensional information of neck joint points in the skeleton information is obtained through the skeleton information of the head, since the neck supports the head in the human body structure, the neck is equivalent to a center of gravity point of the head, and the head circumference is a measure of the size of the head, which is relevant to establishing a head proxy, in this embodiment, the neck joint points can be used as the center point of the head.

And S32, taking the average value of the coordinates of the grid points corresponding to the top of the head and the tip of the nose in the vertical direction as the coordinates of the head circumference in the vertical direction.

In this embodiment, the normal measurement of the head circumference is performed by passing through the upper-eyebrow-arch protrusion and measuring the head circumference around the occipital tuberosity, but the detailed setting is not performed for the above points in the three-dimensional model of the human body, so in this step, the average value of the coordinates of the grid points corresponding to the top of the head and the tip of the nose in the vertical direction in the three-dimensional model of the human body is used as the coordinates of the plane where the head circumference is located in the vertical direction, so that the horizontal section passing through the head circumference can be determined later.

And S33, determining neck projection points and nose tip projection points of the grid points corresponding to the neck joint points and the nose tips on the cross section of the head circumference in the horizontal direction according to the three-dimensional information of the neck joint points and the grid information of the grid points corresponding to the nose tips.

In this embodiment, according to the three-dimensional information of the neck joint point and the grid information of the grid point corresponding to the nose tip, the neck projection point and the nose tip projection point of the grid point corresponding to the neck joint point and the nose tip on the cross section of the head circumference in the horizontal direction are obtained, that is, according to the three-dimensional information of the neck joint point, the coordinate of the neck joint point in the vertical direction is replaced by the coordinate of the horizontal cross section in the vertical direction, that is, the coordinate of the neck projection point can be obtained, and similarly, the coordinate of the nose tip projection point can be obtained.

S34, taking the neck projection point as an origin, generating four rays on the cross section of the head circumference in the horizontal direction; the cross section of the head circumference in the horizontal direction is divided into four equal parts by the four rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the neck projection point and the nose tip projection point.

In this embodiment, the neck joint point is used as a starting point, four rays of a cross section in the horizontal direction of the head circumference are generated, the horizontal cross section is divided into four equal parts by the rays, and an included angle formed by two rays is divided equally by a connecting line of the neck projection point and the nose tip projection point.

Specifically, the projection nose tip projection point of the nose tip point on the cross section is connected with the neck projection point and the nose tip projection point, so that the four rays are emitted from the neck projection point to the nose tip projection point as a reference direction, the reference direction is 0 degree, the neck projection point is taken as an origin, and the included angles are 45 degrees, 135 degrees, 225 degrees and 315 degrees, so that the four rays described in the above embodiment can be obtained.

S35, taking the grid point nearest to the head circumference intersection point as the grid point corresponding to the head circumference according to the grid information of the head; wherein the intersection point of the head circumference is the intersection point of the ray and the grid structure of the head.

In the present embodiment, based on the mesh information of the head, the intersection of the ray and the mesh structure of the head is defined as a head circumference intersection, and the mesh point closest to the head circumference intersection is defined as a head circumference corresponding mesh point.

Compared with the construction method provided by the embodiment, the method for constructing the three-dimensional model provided by the embodiment of the invention is different from the method for constructing the three-dimensional model provided by the embodiment of the invention in that the method for determining the grid points corresponding to the hindbrain spoon is provided.

As shown in fig. 5, in this embodiment, specifically, the method for determining grid points corresponding to the hindbrain includes the following steps:

and S41, acquiring three-dimensional information of the neck joint point according to the bone information of the head.

And S42, determining neck projection points of the neck joint points on the cross section of the horizontal direction where the grid points corresponding to the nose tips are located according to the three-dimensional information of the neck joint points.

In this embodiment, the neck projection point on the cross section of the neck joint point in the horizontal direction where the grid point corresponding to the nose tip is located is obtained according to the grid information of the three-dimensional information of the neck joint point, that is, the coordinates of the neck joint point in the vertical direction are replaced with the coordinates of the horizontal cross section in the vertical direction according to the three-dimensional information of the neck joint point, that is, the coordinates of the neck projection point can be obtained.

S43, taking the grid point closest to the point of intersection of the hindbrain scoop as the grid point corresponding to the hindbrain scoop according to the grid information of the head; wherein, the back head-spoon intersection point is the intersection point of the extension line of the connecting line of the grid point corresponding to the nose tip and the neck projection point and the grid structure of the head.

In this embodiment, based on the mesh information of the head, the intersection point of the extension line of the connecting line between the mesh point corresponding to the nose tip and the projected point of the neck and the mesh structure of the head is set as the posterior brain-scoop intersection point, and the mesh point closest to the posterior brain-scoop intersection point is set as the mesh point corresponding to the head circumference.

Compared with the construction method provided by the embodiment, the embodiment of the invention provides a method for determining the key points of the trunk.

As shown in fig. 6, in particular, in this embodiment, the method for determining the torso key points includes the following steps:

and S51, determining the three-dimensional information of the left shoulder joint point, the three-dimensional information of the right shoulder joint point and the three-dimensional information of the second spine joint point according to the skeleton information of the trunk.

In this embodiment, the three-dimensional information of the left shoulder joint point, the three-dimensional information of the right shoulder joint point, and the three-dimensional information of the second spine joint point are obtained through the skeleton information of the trunk, because in the human body structure, the spine is the central position of the trunk, the shoulder key points of the trunk part of the human body three-dimensional model should be the grid points representing the position of the shoulder thickness, and the shoulder joint points on the trunk are the points corresponding to the thicker area of the shoulder.

And S52, determining the average value of the coordinates of the left shoulder joint point and the right shoulder joint point in the vertical direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, and taking the average value as the coordinates of the trunk key point in the vertical direction.

In this embodiment, the average of the coordinates of the left shoulder joint point and the right shoulder joint point in the vertical direction is taken as the coordinate of the torso joint point in the vertical direction, where the torso key point acquired in this embodiment is the torso key point corresponding to the shoulder.

And S53, determining second spine projection points and nose tip projection points of the grid points corresponding to the second spine joint points and the nose tips on the section of the horizontal direction where the trunk key points are located according to the three-dimensional information of the second spine joint points and the grid information of the grid points corresponding to the nose tips.

In this embodiment, according to the three-dimensional information of the second spine joint point and the grid information of the grid point corresponding to the nose tip, a second spine projection point and a nose tip projection point of the grid point corresponding to the second spine joint point and the nose tip on the cross section of the trunk in the horizontal direction where the key point is located are obtained, that is, according to the three-dimensional information of the second spine joint point, the coordinate of the second spine joint point in the vertical direction is replaced by the coordinate of the horizontal cross section in the vertical direction, that is, the coordinate of the second spine projection point can be obtained, and similarly, the coordinate of the nose tip projection point can be obtained.

And S54, determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on the section of the trunk key point in the horizontal direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point.

In this embodiment, a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the left shoulder joint point on a cross section of the torso key point in the horizontal direction are obtained according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, that is, according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, a coordinate of the left shoulder projection point may be obtained by replacing a coordinate of the left shoulder joint point in the vertical direction with a coordinate of the horizontal cross section in the vertical direction, and in the same way, a coordinate of the right shoulder projection point may be obtained.

And S55, establishing a first ray which is emitted from the second spine projection point to the nose tip projection point according to the second spine projection point and the nose tip projection point by taking the second spine projection point as a starting point.

In this embodiment, a first ray pointing from the second spine projection point to the nose tip projection point is established with the second spine projection point as a starting point, and the first ray may be used to determine the front of the three-dimensional model of the human body.

S56, taking the grid point closest to the intersection point of the trunk as a trunk key point according to the grid information of the trunk; the trunk intersection point is an intersection point of a second ray constructed by taking the left shoulder projection point as a starting point and a grid structure of the trunk, the trunk intersection point is an intersection point of a third ray constructed by taking the right shoulder projection point as a starting point and the grid structure of the trunk, and the directions of the first ray, the second ray and the third ray are the same.

In this embodiment, a left shoulder projection point and a right shoulder projection point are respectively used as starting points, a second ray and a third ray are constructed, directions of the first ray, the second ray and the third ray are ensured to be the same, the second ray and the third ray both point to the front of the three-dimensional model of the human body, intersection points of the second ray and the third ray and a grid structure of the trunk are projections of the left shoulder projection point and the right shoulder projection point in the front of the trunk, and a grid point closest to the intersection point of the trunk is used as a key point of the trunk.

As shown in fig. 7, in particular, in this embodiment, the method for determining the torso key points includes the following steps:

s61, determining three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point, three-dimensional information of a first spine joint point and three-dimensional information of a second spine joint point according to skeleton information of a trunk; wherein the coordinate of the first spinal joint point in the vertical direction is greater than the coordinate of the second spinal joint point in the vertical direction.

In this embodiment, the three-dimensional information of the left shoulder joint point, the three-dimensional information of the right shoulder joint point, the three-dimensional information of the first spine joint point, and the three-dimensional information of the second spine joint point are obtained through the skeleton information of the trunk.

In this embodiment, since the chest contour point corresponds to a portion of the thoracic cavity of the three-dimensional model of the human body, and the region of the thoracic cavity is large, in this step, the first spinal joint point may be a spinal joint point corresponding to the upper end of the thoracic cavity or a higher spinal joint point, and the second spinal joint point may be a spinal joint point corresponding to the lower end of the thoracic cavity or a lower spinal joint point.

And S62, establishing a section in the horizontal direction of the first spinal joint point as a spinal reference section.

And S63, determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on the spine reference section according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point.

In this embodiment, according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, the left shoulder projection point and the right shoulder projection point of the left shoulder joint point and the left shoulder joint point on the spine reference section are obtained, that is, according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, the coordinate of the left shoulder projection point can be obtained by replacing the coordinate of the left shoulder joint point in the vertical direction with the coordinate of the spine reference section in the vertical direction, and similarly, the coordinate of the right shoulder projection point can be obtained.

And S64, establishing a connecting line for connecting the left shoulder projection point and the right shoulder projection point as a reference connecting line.

S65, establishing a perpendicular line by taking the first spine joint point as a orthocenter, and dividing the spine reference section into a first reference section and a second reference section; wherein the perpendicular line is perpendicular to the reference line.

In this embodiment, since the contour points of the thoracic cavities include the left and right thoracic cavities, and the contour points of the left and right thoracic cavities may be changed by the model created by the user, the reference section of the spine is divided into the first reference section and the second reference section according to the left shoulder projection point and the right shoulder projection point in this step.

And S66, vertically moving the first reference section and the second reference section downwards to a second spinal joint point, and acquiring the distance between each grid point in the first reference section and the reference connecting line in real time and the distance between each grid point in the second reference section and the reference connecting line in real time according to the grid information of the trunk.

In this embodiment, by moving the first reference cross section and the second reference cross section vertically downward to the second spinal joint point, the first reference cross section and the second reference cross section will meet the grid points of the three-dimensional model surface of the human body in sequence, and in this step, the distance between the grid point appearing on the reference cross section and the reference connecting line is obtained, that is, the relative position of the grid points of the three-dimensional model surface of the human body can be confirmed.

And S67, taking the grid point with the maximum distance from the reference connecting line in the first reference cross section and the grid point with the maximum distance from the reference connecting line in the second reference cross section as the key point of the trunk.

In this embodiment, the finally determined torso key point, i.e. the maximum point of the chest contour in the three-dimensional model of the human body, i.e. the torso thickness corresponding to the torso key point is maximum.

As shown in fig. 8, in particular, in this embodiment, the method for determining the torso key points includes the following steps:

and S71, determining the three-dimensional information of the hip joint point and the three-dimensional information of the first spine joint point according to the skeleton information of the trunk.

In the present embodiment, three-dimensional information of hip joint points in the skeleton information is obtained through the skeleton information of the trunk, and in the present embodiment, the hip joint points may be lower end points of the spine bones or connection points of the hip bones and the spine bones.

And S72, determining a first spine projection point and a nose tip projection point of the grid points corresponding to the first spine joint point and the nose tip on the cross section of the hip joint point in the horizontal direction according to the three-dimensional information of the first spine joint point and the grid information of the grid points corresponding to the nose tip.

In this embodiment, a first spine projection point and a nose tip projection point of grid points corresponding to a first spine joint point and a nose tip on a cross section of the hip joint point in the horizontal direction are obtained from three-dimensional information of the first spine joint point and grid information of grid points corresponding to the nose tip.

S73, generating three rays on the cross section of the hip joint point in the horizontal direction by taking the first spine projection point as an origin; the cross section of the hip joint point in the horizontal direction is divided into three equal parts by the three rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the first spine projection point and the nose tip projection point.

In this embodiment, the first spine projection point is used as a starting point, three rays of a section of the hip joint point in the horizontal direction are generated, the horizontal section is trisected by the rays, and an included angle formed by two rays is ensured to be bisected by a connecting line of the first spine projection point and the nose tip projection point.

Specifically, finding the projection of a first spine joint point on a section in the horizontal direction, finding a nose tip projection point of the nose tip point on the section, and connecting the first spine projection point with the nose tip projection point, wherein the direction from the first spine projection point to the nose tip projection point is a reference direction, the reference direction is 0 degree, the first spine projection point is an origin, and three rays are emitted with included angles of 60 degrees, 180 degrees and 300 degrees respectively, so that the rays can be obtained.

S74, taking the grid point closest to the hip intersection point as a trunk key point according to the trunk grid information; wherein, the buttock point of intersection is the point of intersection of the grid structure of ray and trunk.

In this embodiment, based on the mesh information of the trunk, the intersection of the ray and the mesh structure of the trunk is set as the hip intersection, and the mesh point closest to the hip intersection is set as the trunk key point.

As shown in fig. 9, in particular, in this embodiment, the method for determining the torso key points includes the following steps:

and S81, determining the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point according to the skeleton information of the trunk.

In the present embodiment, three-dimensional information of the left hip joint point and three-dimensional information of the right hip joint point are acquired from skeleton information of the torso.

And S82, determining the mean value of the coordinates of the left crotch bone joint point and the right crotch bone joint point in the vertical direction according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point, and taking the mean value as the coordinates of the trunk key points in the vertical direction.

In the present embodiment, the mean value of the three-dimensional information of the left crotch bone joint point and the coordinates of the right crotch bone joint point in the vertical direction is taken as the coordinates of the trunk joint point in the vertical direction, wherein the trunk key point acquired in the present embodiment is the trunk key point corresponding to the crotch contour point.

And S83, establishing a horizontal section at the key point of the trunk as a crotch bone reference section.

And S84, determining the left crotch bone projection point and the right crotch bone projection point of the left crotch bone joint point and the left crotch bone joint point on the crotch bone reference section according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point.

In this embodiment, the left crotch bone projection point and the right crotch bone projection point of the left crotch bone joint point and the right crotch bone joint point on the section of the trunk in the horizontal direction where the trunk key point is located are obtained according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point, that is, the coordinates of the left crotch bone joint point in the vertical direction are replaced by the coordinates of the horizontal section in the vertical direction according to the three-dimensional information of the left crotch bone joint point, that is, the coordinates of the left crotch bone projection point can be obtained, and the coordinates of the right crotch bone projection point can be obtained in the same way.

S85, establishing a first ray and a second ray on the crotch bone reference section by taking the left crotch bone projection point as a starting point; and the connecting line of the projection point of the left crotch bone and the right crotch bone divides an included angle formed by the first ray and the second ray into two halves.

In this embodiment, a first ray and a second ray on a crotch bone reference section are established with a left crotch bone projection point as a starting point, and a connecting line between the left crotch bone projection point and the right crotch bone is ensured to bisect an included angle formed by the first ray and the second ray.

S86, establishing a third ray and a fourth ray on the crotch bone reference section by taking the right crotch bone projection point as a starting point; and the connecting line of the projection point of the left crotch bone and the right crotch bone divides an included angle formed by the third ray and the fourth ray into two halves.

In this embodiment, a third ray and a fourth ray on the crotch reference cross-section are established with the right crotch projection point as the starting point, and the connection line between the left crotch projection point and the right crotch is ensured to bisect the angle formed by the third ray and the fourth ray.

Specifically, for example, the left crotch projection point is used as the origin, the direction from the right crotch to the left crotch is 0 degree, and the included angles are 60 degrees and-60 degrees, respectively, which are the first ray and the second ray. And taking the projection point of the right crotch bone as an origin, setting the direction from the left crotch bone to the right crotch bone to be 0 degree, and making two rays with included angles of 60 degrees and-60 degrees respectively, namely a third ray and a fourth ray.

S87, taking the grid point closest to the crotch bone intersection point as a trunk key point according to the trunk grid information; the crotch bone intersection point is the intersection point of the first ray, the second ray, the third ray and the fourth ray with the grid structure of the trunk.

In the present embodiment, based on the mesh information of the trunk, the intersection of the ray and the mesh structure of the trunk is taken as a crotch bone intersection, and the mesh point closest to the crotch bone intersection is taken as a trunk key point.

The embodiment of the invention provides a three-dimensional model building method, which is implemented on the basis of the above embodiment, and comprises the steps of building a body agent of four limbs outside a head agent body and a body agent body, wherein the building method of the body agent of the four limbs comprises the following steps: acquiring grid information of four limbs of the human body three-dimensional model; acquiring three-dimensional information of joint points corresponding to four limbs according to the grid information; constructing an agent body corresponding to the grid information of the four limbs based on the three-dimensional information; and replacing four limbs in the human body three-dimensional model by the agent body to obtain the simplified human body three-dimensional model.

Specifically, in this embodiment, the proxy of the four limbs may be composed of two hemispheres and a cylinder, and the generation of the partial proxy is calculated by taking the right arm between the right shoulder and the right elbow as an example, first we know the spatial coordinates of the right shoulder and the right elbow, which we use as the center points c1 and c2 of the two bottom surfaces of the cylinder.

Next we calculate the radius r_c。

First we choose one of c1 and c2, for example c1, and we want to find the reference point set P1, which is the vertex of the eligible mesh near c1, P1.

The vertices P of the mesh within the set of reference points P1 should satisfy:

1. the angle c2c1p < alpha, the angle c2c1p is an included angle formed by a point c2, a point c1 and a point p, namely the included angle formed by the point c2, the point c1 and the point p is smaller than alpha, and the alpha is a preset angle.

D (c1, p) < D, D (c1, p) is the distance from the point c1 to the point p, namely the distance from the point c1 to the point p is smaller than D, and D is a preset distance.

Calculating a reference radius

l1 is the number of points P in the set of reference points P1, d (c1, P) is the distance from point c1 to point P, Σ_pinP1d (c1, P) is the accumulation of the distances from point c1 to each point P in the set of reference points P1.

Similarly, we can obtain a qualified reference point set P2 near c2 by the above method.

Calculating a reference radius

l2 is the number of points P in the set of reference points P2, d (c2, P) is the distance from point c2 to point P, Σ_pinP2d (c2, P) is the accumulation of the distances from point c2 to each point P in the set of reference points P2.

Radius r of sphere_cW1 × r1+ w2 × r2, w1 and w2 are preset weight values.

The points c1 and c2 of the centers of the two bottom surfaces of the cylinder and the radius r of the bottom surface of the cylinder, which is also the radius of the sphere, can be calculated through the process_cAnd then get the corresponding agent, can get the agent of the four limbs similarly, substitute the four limbs of the human three-dimensional model through the agent, get the human three-dimensional model that simplifies and finishes.

In a specific embodiment, the present disclosure provides a method for constructing a three-dimensional model, which simplifies the whole three-dimensional model of a human body by constructing a proxy body at each position of the three-dimensional model of the human body and replacing the corresponding position of the three-dimensional model of the human body with the proxy body, and specifically, the method can be implemented as follows:

firstly, the construction method of the agent body of the four limbs comprises the following steps: acquiring grid information of four limbs of the human body three-dimensional model; acquiring three-dimensional information of joint points corresponding to four limbs according to the grid information; and constructing a proxy body corresponding to the grid information of the four limbs based on the three-dimensional information.

Next we calculate the radius r_c。

We choose one of c1 and c2, for example c1, and we want to find a reference point set P1, which is the vertex of the eligible mesh near c1, P1.

Calculating a reference radius

Calculating a reference radius

Radius r of sphere_cW1 × r1+ w2 × r2, w1 and w2 are preset weight values.

The points c1 and c2 of the centers of the two bottom surfaces of the cylinder and the radius r of the bottom surface of the cylinder, which is also the radius of the sphere, can be calculated through the process_cAnd then get the corresponding agent, and in the same way, get the agent of the four limbs.

Secondly, the construction method of the agent body of the body and the head comprises the following steps: acquiring grid information and skeleton information of a head and a trunk of a human body three-dimensional model; determining a head key point and a trunk key point according to the grid information and the skeleton information; and constructing a head proxy body according to the head key points, and constructing a body proxy body according to the body key points.

Specifically, in this embodiment, regarding the proxy of the head, we reconstruct the mesh structure, and select the key points (the original mesh vertices closest to the key points) of the head, specifically, for example, eyes (two points), nose tip (one point), mouth corners (two points), chin tip (one point), ears (two points), vertex (one point), and head circumference (two points). The key point is only one specific implementation mode for realizing the scheme, and other modes can be adopted to select the key point to realize the simplification of the head.

Specifically, in this embodiment, with respect to the proxy of the torso, we reconstruct the mesh structure, selecting the key points of the torso (the original mesh vertices closest to the key points), specifically, for example, the torso key points located in the shoulder region, the torso key points located in the chest, the torso key points located in the hip, and the torso key points located in the crotch. The key point is only one specific implementation mode for realizing the scheme, and other modes can be adopted to select the key point to realize the trunk simplification.

Wherein, eyes, nose tip, mouth angle, chin tip, ears and vertex can be directly obtained in the human body three-dimensional model.

The key point corresponding to the head circumference can be determined by the following method: acquiring three-dimensional information of neck joint points according to the bone information of the head; taking the mean value of the coordinates of the grid points corresponding to the top of the head and the tip of the nose in the vertical direction as the coordinates of the head circumference in the vertical direction; determining neck projection points and nose tip projection points of grid points corresponding to the neck joint points and the nose tips on a cross section of the head circumference in the horizontal direction according to the three-dimensional information of the neck joint points and the grid information of the grid points corresponding to the nose tips; taking the neck projection point as an origin, and generating four rays on the section of the head circumference in the horizontal direction; the cross section of the head circumference in the horizontal direction is divided into four equal parts by the four rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the neck projection point and the nose tip projection point; according to the grid information of the head, taking the grid point closest to the intersection point of the head circumference as the grid point corresponding to the head circumference; wherein the intersection point of the head circumference is the intersection point of the ray and the grid structure of the head.

The key points corresponding to the hindbrain spoons can be determined by the following method: acquiring three-dimensional information of neck joint points according to the bone information of the head; determining neck projection points of the neck joint points on a section of the horizontal direction where grid points corresponding to the nose tip are located according to the three-dimensional information of the neck joint points; taking the grid point closest to the point of intersection with the hindbrain scoop as the grid point corresponding to the hindbrain scoop according to the grid information of the head; wherein, the back head-spoon intersection point is the intersection point of the extension line of the connecting line of the grid point corresponding to the nose tip and the neck projection point and the grid structure of the head.

The torso keypoints located in the shoulder region may be determined by: determining three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point and three-dimensional information of a second spine joint point according to skeleton information of the trunk; determining the mean value of the coordinates of the left shoulder joint point and the right shoulder joint point in the vertical direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, and taking the mean value as the coordinate of the trunk key point in the vertical direction; determining a second spine projection point and a nose tip projection point of the grid points corresponding to the second spine joint point and the nose tip on the section of the horizontal direction where the trunk key point is located according to the three-dimensional information of the second spine joint point and the grid information of the grid points corresponding to the nose tip; determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on a section of the trunk key point in the horizontal direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point; establishing a first ray which is emitted from the second spine projection point to the nose tip projection point according to the second spine projection point and the nose tip projection point by taking the second spine projection point as a starting point; taking the mesh point closest to the trunk intersection point as a trunk key point according to the mesh information of the trunk; the trunk intersection point is an intersection point of a second ray constructed by taking the left shoulder projection point as a starting point and a grid structure of the trunk, the trunk intersection point is an intersection point of a third ray constructed by taking the right shoulder projection point as a starting point and the grid structure of the trunk, and the directions of the first ray, the second ray and the third ray are the same.

The torso key points at the chest may be determined by: determining three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point, three-dimensional information of a first spine joint point and three-dimensional information of a second spine joint point according to skeleton information of a trunk; the coordinate of the first spine joint point in the vertical direction is larger than the coordinate of the second spine joint point in the vertical direction; establishing a section in the horizontal direction of the first spinal joint point as a spinal reference section; determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on the spine reference section according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point; establishing a connecting line for connecting the left shoulder projection point and the right shoulder projection point as a reference connecting line; establishing a perpendicular line by taking the first spine joint point as a vertical center, and dividing the spine reference section into a first reference section and a second reference section; wherein the perpendicular line is perpendicular to the reference line; vertically moving the first reference section and the second reference section downwards to a second spinal joint point, and acquiring the distance between each grid point in the first reference section and a reference connecting line in real time and the distance between each grid point in the second reference section and the reference connecting line in real time according to the grid information of the trunk; and taking the grid point with the maximum distance from the reference connecting line in the first reference section and the grid point with the maximum distance from the reference connecting line in the second reference section as the key points of the trunk.

The torso key points located at the buttocks can be determined by the following method: determining three-dimensional information of hip joint points and three-dimensional information of first spine joint points according to skeleton information of a trunk; determining a first spine projection point and a nose tip projection point of grid points corresponding to the first spine joint point and the nose tip on a section of the hip joint point in the horizontal direction according to the three-dimensional information of the first spine joint point and the grid information of the grid points corresponding to the nose tip; generating three rays on the cross section of the hip joint point in the horizontal direction by taking the first spine projection point as an origin; the cross section of the hip joint point in the horizontal direction is divided into three equal parts by the three rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the first spine projection point and the nose tip projection point; taking the mesh point closest to the hip intersection point as a trunk key point according to the mesh information of the trunk; wherein, the buttock point of intersection is the point of intersection of the grid structure of ray and trunk.

The torso key point located at the crotch can be determined by: determining three-dimensional information of a left crotch bone joint point and three-dimensional information of a right crotch bone joint point according to skeleton information of a trunk; determining the mean value of the coordinates of the left crotch bone joint point and the right crotch bone joint point in the vertical direction according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point, and taking the mean value as the coordinate of the trunk key point in the vertical direction; establishing a horizontal section at a key point of the trunk as a crotch bone reference section; determining a left crotch bone projection point and a right crotch bone projection point of the left crotch bone joint point and the left crotch bone joint point on a crotch bone reference section according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point; establishing a first ray and a second ray on a crotch bone reference section by taking the left crotch bone projection point as a starting point; wherein, the connecting line of the projection point of the left crotch bone and the right crotch bone divides the included angle formed by the first ray and the second ray into two halves; establishing a third ray and a fourth ray on the crotch bone reference section by taking the right crotch bone projection point as a starting point; wherein, the connecting line of the projection point of the left crotch bone and the right crotch bone divides the included angle formed by the third ray and the fourth ray equally; taking a grid point closest to a crotch bone intersection point as a trunk key point according to the grid information of the trunk; the crotch bone intersection point is the intersection point of the first ray, the second ray, the third ray and the fourth ray with the grid structure of the trunk.

And respectively constructing a corresponding head proxy body and a corresponding body proxy body through the head key points and the body key points.

In this embodiment, constructing the agent by the head key point and the torso key point may be implemented as follows: connecting every two head key points to obtain a first grid structure; removing the connecting lines inside the first grid structure to obtain a head grid structure as a head agent; connecting every two trunk key points to obtain a second grid structure; and removing the connecting line inside the second grid structure to obtain the trunk grid structure as a trunk agent.

Finally, each part in the human body three-dimensional model is replaced by the four-limb agent body, the head agent body and the trunk agent body constructed in the embodiment, so that the human body three-dimensional model is simplified, the collision detection is carried out on the simplified human body three-dimensional model, the agent calculation of the human body three-dimensional model can be rapidly realized, and the data processing efficiency is improved.

As shown in fig. 10, an embodiment of the present invention provides a three-dimensional model building apparatus, including: the device comprises a first processing unit, a second processing unit, a third processing unit and a fourth processing unit.

In this embodiment, the first processing unit is configured to obtain mesh information and skeleton information of a head and a torso of a three-dimensional model of a human body.

In this embodiment, the second processing unit is configured to determine the head key points and the torso key points according to the mesh information and the skeleton information.

In this embodiment, the third processing unit is configured to construct a head proxy according to the head key points, and construct a torso proxy according to the torso key points.

In this embodiment, the fourth processing unit is configured to replace the head and the torso of the three-dimensional human body model with the head agent and the torso agent, so as to obtain a simplified three-dimensional human body model.

In this embodiment, the head key points include: eyes, nose tip, mouth horn, chin tip, ears, vertex, head circumference and back head scoop.

In this embodiment, the second processing unit is specifically configured to obtain three-dimensional information of a neck joint point according to bone information of the head; taking the mean value of the coordinates of the grid points corresponding to the top of the head and the tip of the nose in the vertical direction as the coordinates of the head circumference in the vertical direction; determining neck projection points and nose tip projection points of grid points corresponding to the neck joint points and the nose tips on a cross section of the head circumference in the horizontal direction according to the three-dimensional information of the neck joint points and the grid information of the grid points corresponding to the nose tips; taking the neck projection point as an origin, and generating four rays on the section of the head circumference in the horizontal direction; the cross section of the head circumference in the horizontal direction is divided into four equal parts by the four rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the neck projection point and the nose tip projection point; according to the grid information of the head, taking the grid point closest to the intersection point of the head circumference as the grid point corresponding to the head circumference; wherein the intersection point of the head circumference is the intersection point of the ray and the grid structure of the head.

In this embodiment, the second processing unit is specifically configured to obtain three-dimensional information of a neck joint point according to bone information of the head; determining neck projection points of the neck joint points on a section of the horizontal direction where grid points corresponding to the nose tip are located according to the three-dimensional information of the neck joint points; taking the grid point closest to the point of intersection with the hindbrain scoop as the grid point corresponding to the hindbrain scoop according to the grid information of the head; wherein, the back head-spoon intersection point is the intersection point of the extension line of the connecting line of the grid point corresponding to the nose tip and the neck projection point and the grid structure of the head.

In this embodiment, the second processing unit is specifically configured to determine, according to skeleton information of the trunk, three-dimensional information of the left shoulder joint point, three-dimensional information of the right shoulder joint point, and three-dimensional information of the second spine joint point; determining the mean value of the coordinates of the left shoulder joint point and the right shoulder joint point in the vertical direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point, and taking the mean value as the coordinate of the trunk key point in the vertical direction; determining a second spine projection point and a nose tip projection point of the grid points corresponding to the second spine joint point and the nose tip on the section of the horizontal direction where the trunk key point is located according to the three-dimensional information of the second spine joint point and the grid information of the grid points corresponding to the nose tip; determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on a section of the trunk key point in the horizontal direction according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point; establishing a first ray which is emitted from the second spine projection point to the nose tip projection point according to the second spine projection point and the nose tip projection point by taking the second spine projection point as a starting point; taking the mesh point closest to the trunk intersection point as a trunk key point according to the mesh information of the trunk; the trunk intersection point is an intersection point of a second ray constructed by taking the left shoulder projection point as a starting point and a grid structure of the trunk, the trunk intersection point is an intersection point of a third ray constructed by taking the right shoulder projection point as a starting point and the grid structure of the trunk, and the directions of the first ray, the second ray and the third ray are the same.

In this embodiment, the second processing unit is specifically configured to determine, according to skeleton information of the trunk, three-dimensional information of a left shoulder joint point, three-dimensional information of a right shoulder joint point, three-dimensional information of a first spine joint point, and three-dimensional information of a second spine joint point; the coordinate of the first spine joint point in the vertical direction is larger than the coordinate of the second spine joint point in the vertical direction; establishing a section in the horizontal direction of the first spinal joint point as a spinal reference section; determining a left shoulder projection point and a right shoulder projection point of the left shoulder joint point and the right shoulder joint point on the spine reference section according to the three-dimensional information of the left shoulder joint point and the three-dimensional information of the right shoulder joint point; establishing a connecting line for connecting the left shoulder projection point and the right shoulder projection point as a reference connecting line; establishing a perpendicular line by taking the first spine joint point as a vertical center, and dividing the spine reference section into a first reference section and a second reference section; wherein the perpendicular line is perpendicular to the reference line; vertically moving the first reference section and the second reference section downwards to a second spinal joint point, and acquiring the distance between each grid point in the first reference section and a reference connecting line in real time and the distance between each grid point in the second reference section and the reference connecting line in real time according to the grid information of the trunk; and taking the grid point with the maximum distance from the reference connecting line in the first reference section and the grid point with the maximum distance from the reference connecting line in the second reference section as the key points of the trunk.

In this embodiment, the second processing unit is specifically configured to determine three-dimensional information of hip joint points and three-dimensional information of the first spine joint points according to skeleton information of the torso; determining a first spine projection point and a nose tip projection point of grid points corresponding to the first spine joint point and the nose tip on a section of the hip joint point in the horizontal direction according to the three-dimensional information of the first spine joint point and the grid information of the grid points corresponding to the nose tip; generating three rays on the cross section of the hip joint point in the horizontal direction by taking the first spine projection point as an origin; the cross section of the hip joint point in the horizontal direction is divided into three equal parts by the three rays, and an included angle formed by two rays adjacent to the nose tip projection point is divided equally by a connecting line of the first spine projection point and the nose tip projection point; taking the mesh point closest to the hip intersection point as a trunk key point according to the mesh information of the trunk; wherein, the buttock point of intersection is the point of intersection of the grid structure of ray and trunk.

In this embodiment, the second processing unit is specifically configured to determine three-dimensional information of a left hip joint point and three-dimensional information of a right hip joint point according to skeleton information of a torso; determining the mean value of the coordinates of the left crotch bone joint point and the right crotch bone joint point in the vertical direction according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point, and taking the mean value as the coordinate of the trunk key point in the vertical direction; establishing a horizontal section at a key point of the trunk as a crotch bone reference section; determining a left crotch bone projection point and a right crotch bone projection point of the left crotch bone joint point and the left crotch bone joint point on a crotch bone reference section according to the three-dimensional information of the left crotch bone joint point and the three-dimensional information of the right crotch bone joint point; establishing a first ray and a second ray on a crotch bone reference section by taking the left crotch bone projection point as a starting point; wherein, the connecting line of the projection point of the left crotch bone and the right crotch bone divides the included angle formed by the first ray and the second ray into two halves; establishing a third ray and a fourth ray on the crotch bone reference section by taking the right crotch bone projection point as a starting point; wherein, the connecting line of the projection point of the left crotch bone and the right crotch bone divides the included angle formed by the third ray and the fourth ray equally; taking a grid point closest to a crotch bone intersection point as a trunk key point according to the grid information of the trunk; the crotch bone intersection point is the intersection point of the first ray, the second ray, the third ray and the fourth ray with the grid structure of the trunk.

In this embodiment, the third processing unit is specifically configured to connect every two head key points to obtain a first grid structure; removing the connecting lines inside the first grid structure to obtain a head grid structure as a head agent; connecting every two trunk key points to obtain a second grid structure; and removing the connecting line inside the second grid structure to obtain the trunk grid structure as a trunk agent.

As shown in fig. 11, an embodiment of the present invention provides a three-dimensional model building system, which includes a processor 1110, a communication interface 1120, a memory 1130, and a communication bus 1140, wherein the processor 1110, the communication interface 1120, and the memory 1130 complete communication with each other through the communication bus 1140;

a memory 1130 for storing computer programs;

the processor 1110, when executing the program stored in the memory 1130, implements the following steps:

determining a head key point and a trunk key point according to the grid information and the skeleton information;

In the electronic device provided by the embodiment of the present invention, the processor 1110 obtains the mesh information and skeleton information of the head and the trunk of the three-dimensional human model by executing the program stored in the memory 1130, determines the key points of the head and the key points of the trunk according to the mesh information and the skeleton information, constructs a proxy corresponding to the head and the trunk according to the key points of the head and the trunk, and replaces the corresponding parts in the three-dimensional human model with the proxy to simplify the three-dimensional human model.

The communication bus 1140 mentioned in the above electronic device may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The communication bus 1140 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus.

The communication interface 1120 is used for communication between the electronic device and other devices.

The memory 1130 may include a Random Access Memory (RAM) 1130, and may also include a non-volatile memory 1130, such as at least one disk memory 1130. Optionally, the memory 1130 may also be at least one memory device located remotely from the processor 1110.

The processor 1110 may be a general-purpose processor 1110, and includes a Central Processing Unit (CPU) 1110, a Network Processor (NP) 1110, and the like; the device may also be a digital signal processor 1110 (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, or discrete hardware components.

Embodiments of the present invention provide a computer-readable storage medium, which stores one or more programs, and the one or more programs are executable by one or more processors 1110 to implement the three-dimensional model building method according to any of the above embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions according to the embodiments of the invention are brought about in whole or in part when the computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wirelessly (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk (ssd)), among others.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A method of constructing a three-dimensional model, the method comprising:

2. The construction method according to claim 1, wherein the head keypoints comprise: eyes, nose tip, mouth horn, chin tip, ears, vertex, head circumference and back head scoop.

3. The construction method according to claim 2, wherein the method of determining the grid points corresponding to the head circumference comprises:

4. The construction method according to claim 2, wherein the method for determining grid points corresponding to the hindbrain scoop comprises:

5. The construction method according to claim 2, wherein the method of determining torso keypoints comprises:

6. The construction method according to claim 2, wherein the method of determining torso keypoints comprises:

7. The construction method according to claim 2, wherein the method of determining torso keypoints comprises:

8. The construction method according to claim 2, wherein the method of determining torso keypoints comprises:

9. The construction method according to any one of claims 1 to 8, wherein constructing a head proxy according to the head key points and constructing a trunk proxy according to the trunk key points comprises:

connecting every two head key points to obtain a first grid structure;

connecting the trunk key points pairwise to obtain a second grid structure;

10. A three-dimensional model building apparatus, characterized in that the building apparatus comprises:

11. A three-dimensional model building system is characterized by comprising a processor, a communication interface, a memory and a communication bus, wherein the processor and the communication interface are used for realizing the communication between the processor and the memory through the communication bus;

a memory for storing a computer program;

a processor for implementing the three-dimensional model construction method according to any one of claims 1 to 9 when executing a program stored in a memory.

12. A computer-readable storage medium storing one or more programs which are executable by one or more processors to implement the three-dimensional model building method according to any one of claims 1 to 9.