subdiv: add setting 'mergeBefore' (which applies MergeOnDistance before subdividing

Author: howetuft

include/slg/shapes/subdiv.h

@@ -34,6 +34,7 @@ class SubdivShape : public Shape {
 		const u_int maxLevel,
 		const float maxEdgeScreenSize,
 		const bool enhanced,
+		const bool merge_before,  // Apply merge on distance beforehands
 		const float sharpnessThresholdRadians,
 		const float creaseWeight
 	);
@@ -46,6 +47,7 @@ class SubdivShape : public Shape {
 		luxrays::ExtTriangleMeshRef srcMesh,
 		const u_int maxLevel,
 		const bool enhanced,
+		const bool merge_before,
 		const float sharpnessThresholdRadians,
 		const float creaseWeight
 	);

src/slg/scene/parseshapes.cpp

@@ -341,6 +341,11 @@ ExtTriangleMeshUPtr Scene::CreateShape(const string &shapeName, const Properties
 			Property(propName + ".enhanced")(false)
 		).Get<bool>();
 
+		// Apply merge on distance beforehand
+		const bool mergeBefore = props.Get(
+			Property(propName + ".mergebefore")(false)
+		).Get<bool>();
+
 		const float sharpnessThresholdRadians = props.Get(Property(propName + ".sharpnessthreshold")(0.512)).Get<double>();
 		const float creaseWeight = props.Get(Property(propName + ".creaseweight")(10.0)).Get<double>();
 
@@ -351,6 +356,7 @@ ExtTriangleMeshUPtr Scene::CreateShape(const string &shapeName, const Properties
 			maxLevel,
 			maxEdgeScreenSize,
 			subdivEnhanced,
+			mergeBefore,
 			sharpnessThresholdRadians,
 			creaseWeight
 		);

src/slg/shapes/subdiv.cpp

@@ -1541,6 +1541,7 @@ SubdivShape::SubdivShape(
 	const u_int maxLevel,
 	const float maxEdgeScreenSize,
 	const bool enhanced,
+	const bool merge_before,
 	const float sharpnessThresholdRadians,
 	const float creaseWeight
 ) {
@@ -1556,10 +1557,11 @@ SubdivShape::SubdivShape(
 	if (maxLevel > 0) {
 
 		// Merge vertices on distance
-		auto srcMeshPtr = MergeOnDistanceShape::ApplyMergeOnDistance(
-			rawSrcMesh, std::numeric_limits<float>::min(), true
-		);
-		auto& srcMesh = *srcMeshPtr;
+		auto srcMeshPtr = merge_before ?
+			MergeOnDistanceShape::ApplyMergeOnDistance(
+				rawSrcMesh, std::numeric_limits<float>::min(), true
+			) : nullptr;
+		auto& srcMesh = merge_before ? *srcMeshPtr : rawSrcMesh;
 
 		if (camera && (maxEdgeScreenSize > 0.f)) {
 			SDL_LOG("Subdividing shape " << srcMesh.GetName()
@@ -1594,6 +1596,7 @@ SubdivShape::SubdivShape(
 					*mesh,
 					optimizedLevel,
 					enhanced,
+					merge_before,
 					sharpnessThresholdRadians,
 					creaseWeight
 				);
@@ -1610,7 +1613,7 @@ SubdivShape::SubdivShape(
 		} else {
 			SDL_LOG("Subdividing shape " << srcMesh.GetName() << " at level: " << maxLevel);
 
-			mesh = ApplySubdiv(srcMesh, maxLevel, enhanced, sharpnessThresholdRadians, creaseWeight);
+			mesh = ApplySubdiv(srcMesh, maxLevel, enhanced, merge_before, sharpnessThresholdRadians, creaseWeight);
 		}
 	} else {
 		// Nothing to do, just make a copy
@@ -1687,6 +1690,7 @@ ExtTriangleMeshUPtr SubdivShape::ApplySubdiv(
 	ExtTriangleMeshRef srcMesh,
 	const u_int maxLevel,
 	const bool enhanced,
+	const bool merge_before,
 	const float sharpnessThresholdRadians,
 	const float creaseWeight
 ) {