Enable OIT with reverse depth

TheMostDiligent · TheMostDiligent · commit 289b1ac74549 · 2025-03-04T21:18:41.000-08:00
diff --git a/Shaders/PBR/private/RenderPBR.psh b/Shaders/PBR/private/RenderPBR.psh
@@ -542,7 +542,12 @@ PSOutput main(in VSOutput VSOut,
 #if NUM_OIT_LAYERS > 0
         if (BaseColor.a > OIT_OPACITY_THRESHOLD)
         {
-            float T = GetOITTransmittance(VSOut.ClipPos.z, uint2(VSOut.ClipPos.xy));
+            float D = VSOut.ClipPos.z;
+            if (g_Frame.Camera.fNearPlaneDepth > g_Frame.Camera.fFarPlaneDepth)
+            {
+                D = 1.0 - D;
+            }
+            float T = GetOITTransmittance(D, uint2(VSOut.ClipPos.xy));
             OutColor.rgb *= T;
         }
 #endif
diff --git a/Shaders/PBR/private/UpdateOITLayers.psh b/Shaders/PBR/private/UpdateOITLayers.psh
@@ -52,6 +52,10 @@ PSOutput main(in VSOutput VSOut,
               in bool     IsFrontFace : SV_IsFrontFace)
 {
     float D = VSOut.ClipPos.z;
+    if (g_Frame.Camera.fNearPlaneDepth > g_Frame.Camera.fFarPlaneDepth)
+    {
+        D = 1.0 - D;
+    }
 #if USE_MANUAL_DEPTH_TEST
     if (D >= g_DepthBuffer.Load(int3(VSOut.ClipPos.xy, 0)))
     {

Original file line number	Diff line number	Diff line change
`@@ -542,7 +542,12 @@ PSOutput main(in VSOutput VSOut,`
`542`	`542`	`#if NUM_OIT_LAYERS > 0`
`543`	`543`	`if (BaseColor.a > OIT_OPACITY_THRESHOLD)`
`544`	`544`	`{`
`545`		`- float T = GetOITTransmittance(VSOut.ClipPos.z, uint2(VSOut.ClipPos.xy));`
	`545`	`+ float D = VSOut.ClipPos.z;`
	`546`	`+ if (g_Frame.Camera.fNearPlaneDepth > g_Frame.Camera.fFarPlaneDepth)`
	`547`	`+ {`
	`548`	`+ D = 1.0 - D;`
	`549`	`+ }`
	`550`	`+ float T = GetOITTransmittance(D, uint2(VSOut.ClipPos.xy));`
`546`	`551`	`OutColor.rgb *= T;`
`547`	`552`	`}`
`548`	`553`	`#endif`
Original file line number	Diff line number	Diff line change
`@@ -52,6 +52,10 @@ PSOutput main(in VSOutput VSOut,`
`52`	`52`	`in bool IsFrontFace : SV_IsFrontFace)`
`53`	`53`	`{`
`54`	`54`	`float D = VSOut.ClipPos.z;`
	`55`	`+ if (g_Frame.Camera.fNearPlaneDepth > g_Frame.Camera.fFarPlaneDepth)`
	`56`	`+ {`
	`57`	`+ D = 1.0 - D;`
	`58`	`+ }`
`55`	`59`	`#if USE_MANUAL_DEPTH_TEST`
`56`	`60`	`if (D >= g_DepthBuffer.Load(int3(VSOut.ClipPos.xy, 0)))`
`57`	`61`	`{`