thanks for your input, but this is not a raytracing feasability discussion
z-buffer algorithms retrieve z from interpolating the vertices. here, z is one of the texture components or supplied in another buffer
given a texture and and the z value for each pixel, how do i draw only which pixels are not hidden?
********
A Problem Worthy of Attack
Proves It''s Worth by Fighting Back
hybrid raytracers and programmable pipelines
Due to a paper that yannl posted quite a while ago, i have a modified realtime polygonal grass demo, and it works with localised procedurally defined weather too. All i need to do now is get it to look nide instead of each blade looking like a 5 point polygon. Im trying to get a fragment shader to do it, but i just cant get the right ''look''.
I have 4 levels of detail too, and it runs ~36 fps on a landscape with nothing but grass on a radeon 9700 pro. I''ll fix it eventually when i have time to actually optimise it, and use it.
I have 4 levels of detail too, and it runs ~36 fps on a landscape with nothing but grass on a radeon 9700 pro. I''ll fix it eventually when i have time to actually optimise it, and use it.
The easiest way would be to do it the other way around, write the results of the raytracing to a color buffer and depth texture before you render the polygonal part using that as the rendering target.
You will need to know the internal format of depth textures of course ...
If you dont want to simply write native Z-values to video memory you could always use DX9 level hardware and simply store an extra depth value in alpha or an offscreen buffer, and use that to kill fragments when needed in the pixel shader by comparing it against the depth from raytracing in your texture (will need both floating point framebuffer and texture of course, so that might be slow ... if possible it might be best to use a normal framebuffer with a single component offscreen floating point buffer to store the depth of the polygonal stuff, and use a normal RGB texture and seperate single component floating point texture for your raytracing results ... or does DX9 hardware support 8-8-8-24 formats?).
[edited by - PinkyAndThaBrain on December 31, 2002 9:47:21 PM]
[edited by - PinkyAndThaBrain on December 31, 2002 9:48:13 PM]
You will need to know the internal format of depth textures of course ...
If you dont want to simply write native Z-values to video memory you could always use DX9 level hardware and simply store an extra depth value in alpha or an offscreen buffer, and use that to kill fragments when needed in the pixel shader by comparing it against the depth from raytracing in your texture (will need both floating point framebuffer and texture of course, so that might be slow ... if possible it might be best to use a normal framebuffer with a single component offscreen floating point buffer to store the depth of the polygonal stuff, and use a normal RGB texture and seperate single component floating point texture for your raytracing results ... or does DX9 hardware support 8-8-8-24 formats?).
[edited by - PinkyAndThaBrain on December 31, 2002 9:47:21 PM]
[edited by - PinkyAndThaBrain on December 31, 2002 9:48:13 PM]
This topic is closed to new replies.
Advertisement
Popular Topics
Advertisement