Convert float to float4

Use a surface with a floating point format, and just return the depth from the pixel shader. Or do you actually want to view the depth in some color code?
What is this for?

I'm not sure how to do this in FX composer because I want to pass on the buffer to a pixel shader. And I can't give it on to the pixel shader as a depth buffer because I don't have access to the sampler.

DECLARE_QUAD_DEPTH_BUFFER(DepthBuffer, "D24S8")

[...]

float4 PointLightPS(uniform sampler2D norm, uniform sampler2D depth) {...}
PixelShader = compile ps_3_0 PointLightPS(NormalTextureSampler, DepthBuffer);


But on the other hand FX composer gives me an error when I'm trying to create an offscreen surface with a diffrent surface type:

DECLARE_QUAD_TEX(DepthBuffer, DepthBufferSampler, "D24S8")

You are probably right Erik, your appraoch is the right one but I can't get it to work. I only use the depth buffer to recreate the world position in a pixel shader. I do something like this:

1) Render normals, unlit color, and depth to offscreen surfaces.
2) Generate light map from these surfaces and output color.

EDIT: Got it working in XNA but not FX Composer, probably something i do wrong with the SAS stuff...

[Edited by - 5ule1m4n on November 7, 2009 5:28:38 PM]