Fix nested dielectrics (#248)

skallweitNV · web-flow · commit f7401a5a8b49 · 2020-08-06T15:15:34.000-07:00
diff --git a/Source/Falcor/RenderPasses/Shared/PathTracer/InteriorListHelpers.slang b/Source/Falcor/RenderPasses/Shared/PathTracer/InteriorListHelpers.slang
@@ -114,16 +114,18 @@ float computeRelativeIoR(InteriorList interiorList, uint materialID, bool enteri
     if (entering)
     {
         float toIoR = gScene.materials[materialID].IoR;
+        float fromIoR = 1.f;
         uint topMaterialID = interiorList.getTopMaterialID();
-        float fromIoR = topMaterialID == kNoMaterial ? 1.f : gScene.materials[topMaterialID].IoR;
+        if (topMaterialID != kNoMaterial) fromIoR = gScene.materials[topMaterialID].IoR;
         return fromIoR / toIoR;
     }
     else
     {
         float fromIoR = gScene.materials[materialID].IoR;
+        float toIoR = 1.f;
         uint topMaterialID = interiorList.getTopMaterialID();
         if (topMaterialID == materialID) topMaterialID = interiorList.getNextMaterialID();
-        float toIoR = topMaterialID == kNoMaterial ? 1.f : gScene.materials[topMaterialID].IoR;
+        if (topMaterialID != kNoMaterial) toIoR = gScene.materials[topMaterialID].IoR;
         return fromIoR / toIoR;
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -114,16 +114,18 @@ float computeRelativeIoR(InteriorList interiorList, uint materialID, bool enteri`
`114`	`114`	`if (entering)`
`115`	`115`	`{`
`116`	`116`	`float toIoR = gScene.materials[materialID].IoR;`
	`117`	`+ float fromIoR = 1.f;`
`117`	`118`	`uint topMaterialID = interiorList.getTopMaterialID();`
`118`		`- float fromIoR = topMaterialID == kNoMaterial ? 1.f : gScene.materials[topMaterialID].IoR;`
	`119`	`+ if (topMaterialID != kNoMaterial) fromIoR = gScene.materials[topMaterialID].IoR;`
`119`	`120`	`return fromIoR / toIoR;`
`120`	`121`	`}`
`121`	`122`	`else`
`122`	`123`	`{`
`123`	`124`	`float fromIoR = gScene.materials[materialID].IoR;`
	`125`	`+ float toIoR = 1.f;`
`124`	`126`	`uint topMaterialID = interiorList.getTopMaterialID();`
`125`	`127`	`if (topMaterialID == materialID) topMaterialID = interiorList.getNextMaterialID();`
`126`		`- float toIoR = topMaterialID == kNoMaterial ? 1.f : gScene.materials[topMaterialID].IoR;`
	`128`	`+ if (topMaterialID != kNoMaterial) toIoR = gScene.materials[topMaterialID].IoR;`
`127`	`129`	`return fromIoR / toIoR;`
`128`	`130`	`}`
`129`	`131`	`}`