Study on (1) bicubic Bessel surface. His doctoral thesis "A Subdivision Algorithm for Computer Display of Surfaces" and his later thesis "Recursively Generated B-Spline Surfaces on Arbitrary Topological Surfaces" are all about surface subdivision methods. He and Clark * * * proposed a surface subdivision method called Catmull-Clark. The following is the gumbo model obtained by ed catmull with its algorithm. (2) although Wolfgang Stella? 0? 8er mentioned the idea of "deep buffer" in his doctoral thesis written in 1974, but it is generally believed that ed catmull invented the concept of "Z buffer". Depth buffering is used to deal with which part of the rendered scene is visible and which part is not. The graphics card can correctly generate the usual depth perception effect according to the depth buffer: the closer object blocks the farther object. When the scene to be rendered is large, depth information can be used to eliminate some pixels and improve rendering performance. (3) Invented texture mapping. Texture mapping can make the display effect of objects more realistic. In computer graphics, bitmaps stored in memory are wrapped on the surface of 3D rendering objects. Images (textures) are pasted (mapped) on simple shapes in the scene, just as printed matter is pasted on a plane. This greatly reduces the calculation of making shapes and textures in the scene. (4) Invented digital image synthesis technology. That is, multiple pictures are integrated into one picture, which is very common in animation. (5) Photo Realistic Renderman (PRMAN) renderer is developed for Pixar, which is a commonly used 3D rendering software for making film and television special effects.