Jump to content
  • Advertisement
Sign in to follow this  
Brisco

HLSL question

This topic is 5143 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

hello! I tried to modify the depth value within a pixel shader and have some problems to get it working. I used the following structures: struct PS_INPUT { float4 Pos : POSITION; float4 Tex0 : TEXCOORD0; }; struct PS_OUTPUT { float4 ColOut : COLOR; float4 DepthOut : DEPTH; }; and the following shader code: PS_OUTPUT MainPS(PS_INPUT IN) { PS_OUTPUT Out; Out.ColOut = (0.0f, 0.0f, 0.0f, 1.0f); Out.DepthOut = 1.0f; return Out; } I know, this seems to be not a useful shader and of course it is not. just the problem is, that compilation fails if I use another return type than float4 mapped to COLOR. as target, ps_1_1 is used. All I need is to modify the depth value.

Share this post


Link to post
Share on other sites
Advertisement
hmm... thats interesting. What about this:

!!FP1.0

# f[WPOS] : fragment in trapezoidal space (window position)
# f[TEX0] : fragment's position in post-perspective space of the light


RCP R0.x, f[TEX0].w; # R0.x = 1 / w_L
MUL R1, f[TEX0], R0.x; # R1 = (x_L/w_L, y_L/w_L, z_L/w_L, 1)

MAD R2.z, R1.z, 0.5, 0.5; # R2.z = R1.z * 0.5 + 0.5; depth is now in the range [0;1]

MUL o[DEPR], R2.z, R2.z; # o[DEPR] = z_L/w_L * 0.5 + 0.5; replace "z_T" with "z_L"

MOV o[COLR], f[COL0];

END

this shader code is from the TSM recipe paper at http://www.comp.nus.edu.sg/~tants/tsm/TSM_recipe.html. I don't know too much about the shader assembly language, but I think that MUL o[DEPR], R2.z, r2.z replaces the actual depth buffer value, or is this wrong?

Nevertheless, I tried to compile my HLSL code with ps_2_0 target and it also didn't work.

Share this post


Link to post
Share on other sites
You only need a single float for your DepthOut variable, not a float4. To alter depth in ps_1_x the only way I am aware of doing it is using assembly shaders and using the texdepth/texm3x2depth etc. instructions (only supported in 1.3 and 1.4 in some cases).

-Mezz

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!