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I have a shadow map with enabled hardware percentage-closer filtering. But I also need to get the depth value stored in the shadow map in order to use it for implementing other techniques in the pixel shader. The problem is that all sampling functions (tex2D, tex2Dproj) return the final result of depth comparison. It works well but I cannot get the depth value itself.

Is it possible to preserve hardware PCF for shadow mapping and sample the depth value itself?

There's a limitation though, I cannot handle how the shadow map is created by the application, I can only edit shaders.

Homer
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If you can find an unused SamplerState/sampler2D bind slot, you should be able to declare one there and use it with the generic Sample/tex2D operation. Since the sampler state slot is unbound by the app, the driver should use the default point-sample settings. If the depth buffer supports this type of access, it should return the pre-PCF value.

MooseBoys
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  • I tried this idea myself too but, unfortunately, it didn't seem to work. I'm not 100% sure because I cannot find a good documentation, but it seems like hardware PCF is tricky and it starts working automatically when certain conditions are met. It seems to work with other samplers too because the texture itself was declared in the proper way. It seems like I've tried everything. Whatever I do, I get results of depth testing. – Homer May 31 '16 at 23:54