Merge branch stabilization/2110 into development

Signed-off-by: Chris Burel <burelc@amazon.com>
2021-11-04 13:41:09 -07:00
parent 386ee323dd d85a17536b
commit e958a7d025
4 changed files with 22 additions and 7 deletions
@@ -264,7 +264,7 @@
                                "Attachment": "HairColorRenderTarget"
                            }
                        },
-                        { 
+                        {
                            // The final render target - this is MSAA mode RT - would it be cheaper to
                            // use non-MSAA and then copy?
                            "LocalSlot": "RenderTargetInputOutput",
@@ -280,6 +280,13 @@
                                "Attachment": "DepthLinearInput"
                            }
                        },
+                        {
+                            "LocalSlot": "AccumulatedInverseAlpha",
+                            "AttachmentRef": {
+                                "Pass": "HairShortCutGeometryDepthAlphaPass",
+                                "Attachment": "InverseAlphaRTOutput"
+                            }
+                        },
                        {
                            "LocalSlot": "Depth",
                            "AttachmentRef": {
@@ -32,6 +32,12 @@
                    "SlotType": "Input",
                    "ScopeAttachmentUsage": "Shader"
                },
+                { // Used as the thickness accumulation to block TT (back) lobe lighting
+                    "Name": "AccumulatedInverseAlpha",
+                    "SlotType": "Input",
+                    "ScopeAttachmentUsage": "Shader",
+                    "ShaderInputName": "m_accumInvAlpha"
+                },
                { // For comparing the depth to early disqualify but not to write
                    "Name": "Depth",
                    "SlotType": "Input",
@@ -51,9 +51,6 @@ ShaderResourceGroup PassSrg : SRG_PerPass_WithFallback
    RWTexture2D<uint>               m_fragmentListHead;
    RWStructuredBuffer<PPLL_STRUCT> m_linkedListNodes;
    RWBuffer<uint>                  m_linkedListCounter;
-
-    // Linear depth is used for getting the screen to world transform
-    Texture2D<float>                m_linearDepth;
 }

 //------------------------------------------------------------------------------
@@ -52,6 +52,9 @@ ShaderResourceGroup PassSrg : SRG_PerPass_WithFallback
    //! Originally in TressFXRendering.hlsl this is space 0 
    HairObjectShadeParams   m_hairParams[AMD_TRESSFX_MAX_HAIR_GROUP_RENDER];

+    // Will be used as thickness indication to block TT (back) lobe
+    Texture2D<float>        m_accumInvAlpha;
+
    // Linear depth is used for getting the screen to world transform
    Texture2D<float>        m_linearDepth;

@@ -164,9 +167,11 @@ float4 HairShortCutGeometryColorPS(PS_INPUT_HAIR input) : SV_Target

    float2 pixelCoord = input.Position.xy;
    float depth = input.Position.z;
-    // [To Do] - the thickness will need to be corrected somehow since this technique doesn't 
-    // keeps track of the accumulated alpha / thickness
-    float thickness = alpha;  
+
+    // The following is a quick correction to remove the TT lobe (back lobe) contribution in case 
+    // the hair is thick.  We do that by accumulating alpha from the hair for the blend operation
+    // and this can be used here as an indication of thickness.
+    float thickness = saturate(1.0 - PassSrg::m_accumInvAlpha[int2(pixelCoord)]);
    float3 shadedFragment = TressFXShading(pixelCoord, depth, input.Tangent.xyz, strandColor.rgb, thickness, RenderParamsIndex);

    // Color channel: Pre-multiply with alpha to create non-normalized weighted sum.