Three-dimensional human body multi-gesture modeling method by adopting free-hand sketches

Abstract

The invention provides a three-dimensional human body multi-gesture modeling method by adopting free-hand sketches. The method comprises the following steps of: displaying and drawing a human body feature draft, adjusting an observation viewing angle and a human body gesture as being accorded with the human body draft under a given three-dimensional human body gesture model, and weighting the human body model according to a position relationship between human body gesture model grid points and human body joint points; projecting the human body gesture model and extracting feature projection line sets including contour lines, suggestibility contour lines, valley lines, regression lines and the like under the observation viewing angle and the human body gesture; matching human body draft drawing lines with the feature projection line sets; constructing a Hidden Markov Model according to a geometric relationship between the draft drawing lines and the feature projection line sets; corresponding draft drawing points to the three-dimensional model grid points and calculating displacement parameters of corresponding points; and carrying out deformation on a human body grid model through a mean value coordinate encoding deformation algorithm under the constraint of corresponding three-dimensional model grid point displacement parameters so as to obtain final three-dimensional human body grid models.

Description

technical field [0001] The invention relates to the field of three-dimensional image data processing, in particular to a three-dimensional human body multi-pose modeling method using hand-drawn sketches. Background technique [0002] 3D character modeling technology is one of the important issues in 3D modeling research. It has been widely used in the fields of games, animation and movies. Finding a simple and effective method to build a 3D human mesh model has become an important issue in the field of computer graphics. important topic. [0003] Most of the current virtual character construction methods are realistic methods, which are mainly divided into three categories: creation, reconstruction, and interpolation. Typical methods such as literature 1 Wilhelms J, Van Gelder A. Anatomically based modeling, In: Proceedings of SIGGRAPH'97, ACM SIGGRAPH; 1997.p.173-80, this method mainly creates a hierarchical physical model based on the physiological structure of the human ...

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Problems solved by technology

However, this method can only draw the outline of the human body, and because the matched grid points only depend on the viewing angle, the rationality of the stroke matching process cannot be guaranteed; There is no guarantee that the local detail features of the human model can be satisfied

[0005] To sum up, hand-drawn sketches are an effective way to create a 3D human mesh model, but the existing methods for creating a 3D human mesh model based on a single sketch have great limitations on the user's drawing content and the human body characteristics that can be expressed. For example, the direct construction method and the model deformation method only allow the user to draw the outer contour of the human body, and the matched 3D feature points only depend on the viewing angle, so the rationality of the feature mapping process cannot be guaranteed. Although the parametric template construction method allows the user to draw the skeleton line to reflect the posture of the human body model, but still does not allow users to draw human body feature strokes; the human body generated by the direct construction method is an inflated body model, so it is difficult to express the detailed characteristics of the human body. Depending on the complexity of the human body template, generally only the general shape of the torso of the hands and legs can be represented, but it is difficult to represent complex shape features such as joints and muscles. Although the model deformation method can maintain the geometric characteristics of the mesh model, it does not consider the structural characteristics of the human body. However, it cannot meet the physiological constraints of the human body under the condition of large deformation range.

Obviously, the existing single-view sketch human body modeling method is difficult to meet the user's need for more free body design, how to capture the human body features reflected in the user's drawing process, and map these features reasonably to the feature points of the 3D model grid At the same time, how to meet the constraints of human body structure characteristics in the process of model deformation is also an important issue for the interactive creation of 3D human body mesh models by hand-drawn sketches.

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