Clipping vs Culling
Clipping and culling are techniques that are used extensively in papervision. They are also used in computer graphics when designing a computer game. As both techniques are similar, people are often confused about their differences. This article will highlight the features of these two concepts to make them clear to any reader.
Culling is the process that removes objects not seen by the camera from the frame, thus leaving fewer polygons for the papervision engine to process. On the other hand clipping is the process where polygons that extend past the camera are culled or picked, leading to polygons that are still visible disappear. The area where the object is to be clipped is known as clipping window. Clipping has assumed great significance in the field of video games development these days. Using this technique, games designers can improve frame rate and also the video quality of the game. Clipping is an optimization process that speeds up presentation of the present frame.
Culling on the other hand is a method used for hidden surface removal in a graphic processor. Culling is of two types, magnitude comparison content addressable memory cull operation called MCCAM Cull, and a subpixel cull operation. Other terms associated with culling are back face culling, which decides if a polygon of a graphical object is visible, and occlusion culling, which tries to obviate drawing of polygons which are covered from the view by other polygons that are visible.