Fix issues with contact shadow offset in virtual shadow map shader
- Need to ensure we only offset the depth test, not the clipmap level selection or occluder distance computation
#fyi ola.olsson
#rb none
[CL 14206061 by andrew lauritzen in ue5-main branch]
Sampling a virtual shadow map (directional clipmap or spot light) can now be more easily done by:
- Include FVirtualShadowMapProjectionParameters in shader parameter struct
- Call FVirtualShadowMapArray::SetShaderDefines in ModifyCompilationEnvironment
- Set shader parameters via FVirtualShadowMapArray::SetProjectionParameters
- Calling SampleVirtualShadowMapDepth in the shader
#review ola.olsson
[CL 14201665 by andrew lauritzen in ue5-main branch]
- Remove virtual shadow cascades path and enable clipmaps instead
- Restore full resolution dense shadow maps even when virtual shadow maps are enabled. Combine dense and virtual shadow maps in the screen space shadow mask during projection.
- Remove "copy to fallback" path for virtual shadows; to be replaced by a separate explicit fallback map or similar. This will break Reverb indirect occlusion with Nanite geometry when virtual shadow maps are on for now. For functional testing, disabling virtual shadow maps will still work.
- Fix a bug with point light shadow projection matrices
- Change VirtualShadowMapId's to "int" since we set them to INDEX_NONE (-1) in a bunch of places
[CL 14156014 by andrew lauritzen in ue5-main branch]
