FAQ/Clipping, Culling, and Visibility Testing
- How do I tell if a vertex has been clipped or not?
- When an OpenGL primitive moves placing one vertex outside the window, suddenly the color or texture mapping is incorrect. What's going on?
- I know my geometry is inside the view volume. How can I turn off OpenGL's view-volume clipping to maximize performance?
- When I move the viewpoint close to an object, it starts to disappear. How can I disable OpenGL's zNear clipping plane?
- Occlusion Query
- How do I perform occlusion or visibility testing?
- Stencil Mask
- How do I render to a nonrectangular viewport?
- Raster Position And Clipping
- How do I draw glBitmap() or glDrawPixels() primitives that have an initial glRasterPos() outside the window's left or bottom edge?
- Scissor Test And Framebuffer Clearing
- Why doesn't glClear() work for areas outside the scissor rectangle?
- How does face culling work? Why doesn't it use the surface normal?