fix detection of double-facedness in raytracer

Author: devshgraphicsprogramming

examples_tests/22.RaytracedAO/closestHit.comp

@@ -66,7 +66,7 @@ void main()
 			// positions
 			const vec3 last_vx_pos = load_positions(indices,batchInstanceData);
 			const vec3 geomNormal = cross(dPdBary[0],dPdBary[1]);
-			const bool frontfacing = dot(geomNormal,normalizedV)>0.f;
+			const bool frontfacing = bool((batchInstanceData.determinantSignBit^floatBitsToUint(dot(geomNormal,normalizedV)))&0x80000000u);
 
 			// get material
 			const nbl_glsl_MC_oriented_material_t material = nbl_glsl_MC_material_data_t_getOriented(batchInstanceData.material,frontfacing);

examples_tests/22.RaytracedAO/fillVisBuffer.frag

@@ -29,7 +29,7 @@ void main()
     vec2 bary = nbl_glsl_barycentric_frag_get();
 
     const int triangleIDBitcount = findMSB(MAX_TRIANGLES_IN_BATCH-1)+1;
-	frontFacingTriangleIDDrawID_unorm16Bary_dBarydScreenHalf2x2[0] = bitfieldInsert(gl_PrimitiveID,BackfacingBit_BatchInstanceGUID^(gl_FrontFacing ? 0x0u:0x80000000u),triangleIDBitcount,32-triangleIDBitcount);
+	frontFacingTriangleIDDrawID_unorm16Bary_dBarydScreenHalf2x2[0] = bitfieldInsert(BackfacingBit_BatchInstanceGUID,gl_PrimitiveID,31-triangleIDBitcount,triangleIDBitcount)^(gl_FrontFacing ? 0x0u:0x80000000u);
     frontFacingTriangleIDDrawID_unorm16Bary_dBarydScreenHalf2x2[1] = packUnorm2x16(bary);
     frontFacingTriangleIDDrawID_unorm16Bary_dBarydScreenHalf2x2[2] = packHalf2x16(dFdx(bary));
     frontFacingTriangleIDDrawID_unorm16Bary_dBarydScreenHalf2x2[3] = packHalf2x16(dFdy(bary));

examples_tests/22.RaytracedAO/raygen.comp

@@ -37,8 +37,8 @@ void main()
 			// vis buffer decode
 			const bool frontfacing = !bool(visBuffer[0]&0x80000000u);
 			const int triangleIDBitcount = findMSB(MAX_TRIANGLES_IN_BATCH-1)+1;
-			const uint batchInstanceGUID = bitfieldExtract(visBuffer[0],triangleIDBitcount,31-triangleIDBitcount);
-			const uint triangleID = bitfieldExtract(visBuffer[0],0,triangleIDBitcount);
+			const uint triangleID = bitfieldExtract(visBuffer[0],31-triangleIDBitcount,triangleIDBitcount);
+			const uint batchInstanceGUID = bitfieldExtract(visBuffer[0],0,31-triangleIDBitcount);
 			const vec2 compactBary = unpackUnorm2x16(visBuffer[1]);
 			#ifdef TEX_PREFETCH_STREAM
 			const mat2 dBarydScreen = mat2(unpackHalf2x16(visBuffer[2]),unpackHalf2x16(visBuffer[3]));

examples_tests/22.RaytracedAO/raytraceCommon.glsl

@@ -265,7 +265,7 @@ for (uint i=1u; i!=vertex_depth; i++)
 	// TODO: improve ray offset (maybe using smooth normal wouldn't be a sin)
 	vec3 geomNormal = cross(dPdBary[0],dPdBary[1]);
 	const vec3 absGeomNormal = abs(geomNormal);
-	geomNormal /= max(max(absGeomNormal.x,absGeomNormal.y),max(absGeomNormal.z,0.001f))*96.f;
+	geomNormal /= max(max(absGeomNormal.x,absGeomNormal.y),max(absGeomNormal.z,0.001f))*32.f;
 	uint offset = 0u;
 	for (uint i=0u; i<maxRaysToGen; i++)
 	if (maxT[i]!=0.f)