HLSL - how does vertex shader's output POSITION0 affect pixel shader's texture mapping uv?

Question

It seems POSITION/POSITION0's w devide everything in output struct. thus made pixel shader can do correct perspective mapping.and it cant be removed,otherwise pixel shader wont output anything.

i didn't see any configuration in program code. Is it a fixed default setting for all devices? or can i customize this setting?

Answer 1

You have the choice to disable the perspective correction in hlsl on any interpolator as find here.

The modifier you want is noperspective.