1 reply to this topic

[lomateron]

Rendering to a texture, just wanting to go through all its texels and change them, is a very common thing to do.
I am doing an application were I need to render 1000 times to the same texture in this way.
I think creating the quad and processing it 1000 times is a big lost of GPU time.
Is there any draw() function that goes directly to pixel shader skipping the vertex shader, because it already knows that i am going through all the texels of the render target?

Edited by lomateron, 01 December 2012 - 11:58 AM.

[MJP]

I think creating the quad and processing it 1000 times is a big lost of GPU time.

I really doubt it. Shading 4 vertices is nothing, even if you multiply that by 1000. And the triangle setup/rasterization hardware would just be idling if you weren't using it.

Either way, there's no way to skip the vertex shader. If you wantto skip rasterization altogether, you should use a compute shader.