Three hundred thousand triangles are a problem for game coders because even the best coders can’t handle that much at once. Without severely lagging (FPS below 60). To combat this problem, culling was introduced as a method of the engine removing polygons that are not visible to the camera.
The difference between marketing and real world polygon rates is that marketing rates are the theoretical amount of polygons that a card can achieve. Real world rates are a realistic amount.
The lowest rendering unit that all graphic cards use is a primitive which is almost always a three point triangle.
The advantages of using higher-order surfaces like patches is that they can create a higher polygon rate
Types of occlusion culling techniques include Portal Rendering, which divides a scene into rooms and portals (doors), and computes which sectors are visible by clipping them against portals, and PVS (Potentially visible set) which divides a scene into regions and pre-computes visibility for them.
The five stages of the Basic Graphics Pipeline
1: The game decides what objects, models and textures will appear in the game.
2: The game passes the information to the renderer. In the case of the models, the renderer might first look at the size of the model and where the camera is located and then determine whether the model is onscreen or off-screen.
3: The world visualization system determines where the camera is located and what sections polygons of the world are visible from the camera viewpoint.
Filed under: Games engines, Games research
