In this paper,a self-calibration technique of the camera based on three vanishing points is introduced.

A linear camera calibration method with vanishing point and the invariance of cross-ratio is proposed.

Automatic Examinate the Vanish Point Based on Neighborly Area;

The hiding of two dimension figure is realized by means of Auto CAD Automation technology and through definition and analysis of their geometric character.

We use perspective shifting, hiding, coloring and mapping method to render the surface model of engineering structure, such as pavement, slope, retaining－ wall, bridge, tunnel, and other traffic engineering facilities.

This method has been used to the hiding of 2D assemby drawings and proved to be a simple and practical way for engineers to go with advanced development in their own fields.

The Hidden Method Oriented to Point Distinguishing;

Algorithms for removing the hidden lines of 2D figures in assembly drawing;

A new hidden method for FEM models was introduced.

A hidden line removal algorithm for bi parametric surfaces is presented and illustrated by some experimental results.

The data structure of the assembly part and the key technologies of hidden line removal in the implementation.

It analyses the problems that frequently appear in the output of AutoCAD 3D graph,discusses how can the design can be expressed better on paper and how to show the auxiliary design function of AutoCAD 3D to the most extent,and puts forward corresponding resolution,so as to achieve the effect of blanking and rendering.