What an insight I finally apprehend !

The meeting point of computer graphic and computer vision was human perception.
No wonder I can understand the issues that they are talking about.

It was the reason why I can do the work that was what the discipline of computer graphic do, such as  constructing 3-D models and 3-D animation.

On the other hand,   I also know the principle of recognizing objects and scene, that was what the goal of computer vision.

I am proud of what I learned. That is visual perception.