Method for creating three-dimensional model by using sketch

Abstract

The invention discloses a method for creating a three-dimensional model by using a sketch, which comprises the following steps of: dividing strokes of a freehand sketch into primitive strokes functioning as the outline of an object and threaded strokes acting as three-dimensional effect, identifying the strokes respectively and regularizing the primitive strokes; indicating the geometric constitution of the object by using a conditional rule generation method and realizing rule-driven reasoning by using primitive adjacency relationship under the guidance of drawing threads so as to identify object units and recover the depth information of each object unit; automatically discriminating and completing hidden lines of the object units according to geometric attributes of the object units under the guidance of a drawing thread rule so as to generate a complete three-dimensional object unit; and recreating the three-dimensional model of the object by using a geometric splicing method according to topological relation among the object units. The method has the advantages of expressing the three-dimensional effect with auxiliary threads, such as shade lines and the like, and drawing the perspective projection outline of the object with the freehand sketch so as to improve the degree of freedom of drawing.

Description

technical field [0001] The invention relates to a method for graphic analysis and interpretation, which belongs to the technical field of computer software and computer graphics. Specifically, it is a method for directly converting a freely drawn sketch into a three-dimensional digital image by using processes such as sketch analysis, depth restoration and three-dimensional reconstruction. Model A method of creating a 3D model from a sketch. Background technique [0002] The development of computer technology has brought a series of revolutionary changes to the field of engineering design. The 3D model has become the mainstream of the current engineering application field. The space between product design and modeling appreciation is shortened. However, while the 3D model brings great convenience to the design, it also brings a lot of inconvenience to the model creation. There are two main methods for creating 3D models: one is to use modeling tools such as parametric or v...

AI Technical Summary

Problems solved by technology

[0005] To sum up, hand-drawn sketches are an effective way to create 3D models, but the existing 3D model creation methods based on a single sketch mainly use hand-drawn sketches to express body contours, and either have too many restrictions on user drawing, such as: symbol system and The template-based method is limited to the graphics defined by the system; or the user is required to provide multiple results for selection in the complex optimization process, such as: the optimization method or the line annotation method provides multiple results by the selection criteria defined inside the system, which are determined by pure contours results may differ significantly from user expectations

Obviously, these methods cannot support users to design shapes more freely

In practical applications, when users use a single hand-drawn sketch to express a 3D object, they often draw some auxiliary clues such as shadow lines to indicate its 3D effect, but the existing 3D creation methods based on hand-drawn sketches do not make full use of these clues, so , how to organically combine these clues with body outlines and provide users with a free sketching method is an important issue facing the interactive creation of 3D models from hand-drawn sketches

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