Drivable implicit three-dimensional human body representation method

A drivable implicit three-dimensional human body representation method, comprising:

• step (1):
• constructing a neural network implicit function in a standard coordinate system to represent a geometry and an appearance of a human body, generating a skinning blend weight of any three-dimensional point in each video frame coordinate system by using the neural network implicit function, constructing a neural skinning blend weight field, and transforming the three-dimensional points of a video frame back to the standard coordinate system to represent a dynamic human body;
• step (2):
• learning the neural skinning blend weight field in the standard coordinate system and optimizing the neural network implicit function, in such a manner that the neural network implicit function in the standard coordinate system is capable of being driven to generate a three-dimensional human body in a new state;
• wherein a specific learning process comprises:
• sub-step (2.1):
• rendering the neural network implicit function into a two-dimensional image based on a differentiable volume renderer;
• optimizing a representation of the neural network implicit function by minimizing an error between the rendered two-dimensional image and a corresponding image in a multi-view video;
• wherein in sub-step (2.1), the step of rendering the neural network implicit function into a two-dimensional image based on a differentiable volume renderer comprises:
• sampling a set of three-dimensional points along light projected to a pixel by a camera, transforming the three-dimensional points back to the standard coordinate system by a linear blend skinning algorithm, calculating voxel densities and colors of the three-dimensional points by using the neural network implicit function, and accumulating volume densities and colors on the light to obtain a pixel color;
• sub-step (2.2):
• minimizing a difference between skinning blend weights of corresponding three-dimensional points in the standard coordinate system and the video frame coordinate system, and optimizing the representation of the neural network implicit function of the skinning blend weight;
• and
• step (3) performing generation of a three-dimensional model of the human body and view synthesis based on the optimized neural network implicit function in step (2).