Updated meshoptimizer.

3rdparty/meshoptimizer/src/clusterizer.cpp

@@ -283,6 +283,79 @@ static bool appendMeshlet(meshopt_Meshlet& meshlet, unsigned int a, unsigned int
 	return result;
 }
 
+static unsigned int getNeighborTriangle(const meshopt_Meshlet& meshlet, const Cone* meshlet_cone, unsigned int* meshlet_vertices, const unsigned int* indices, const TriangleAdjacency2& adjacency, const Cone* triangles, const unsigned int* live_triangles, const unsigned char* used, float meshlet_expected_radius, float cone_weight, unsigned int* out_extra)
+{
+	unsigned int best_triangle = ~0u;
+	unsigned int best_extra = 5;
+	float best_score = FLT_MAX;
+
+	for (size_t i = 0; i < meshlet.vertex_count; ++i)
+	{
+		unsigned int index = meshlet_vertices[meshlet.vertex_offset + i];
+
+		unsigned int* neighbors = &adjacency.data[0] + adjacency.offsets[index];
+		size_t neighbors_size = adjacency.counts[index];
+
+		for (size_t j = 0; j < neighbors_size; ++j)
+		{
+			unsigned int triangle = neighbors[j];
+			unsigned int a = indices[triangle * 3 + 0], b = indices[triangle * 3 + 1], c = indices[triangle * 3 + 2];
+
+			unsigned int extra = (used[a] == 0xff) + (used[b] == 0xff) + (used[c] == 0xff);
+
+			// triangles that don't add new vertices to meshlets are max. priority
+			if (extra != 0)
+			{
+				// artificially increase the priority of dangling triangles as they're expensive to add to new meshlets
+				if (live_triangles[a] == 1 || live_triangles[b] == 1 || live_triangles[c] == 1)
+					extra = 0;
+
+				extra++;
+			}
+
+			// since topology-based priority is always more important than the score, we can skip scoring in some cases
+			if (extra > best_extra)
+				continue;
+
+			float score = 0;
+
+			// caller selects one of two scoring functions: geometrical (based on meshlet cone) or topological (based on remaining triangles)
+			if (meshlet_cone)
+			{
+				const Cone& tri_cone = triangles[triangle];
+
+				float distance2 =
+				    (tri_cone.px - meshlet_cone->px) * (tri_cone.px - meshlet_cone->px) +
+				    (tri_cone.py - meshlet_cone->py) * (tri_cone.py - meshlet_cone->py) +
+				    (tri_cone.pz - meshlet_cone->pz) * (tri_cone.pz - meshlet_cone->pz);
+
+				float spread = tri_cone.nx * meshlet_cone->nx + tri_cone.ny * meshlet_cone->ny + tri_cone.nz * meshlet_cone->nz;
+
+				score = getMeshletScore(distance2, spread, cone_weight, meshlet_expected_radius);
+			}
+			else
+			{
+				// each live_triangles entry is >= 1 since it includes the current triangle we're processing
+				score = float(live_triangles[a] + live_triangles[b] + live_triangles[c] - 3);
+			}
+
+			// note that topology-based priority is always more important than the score
+			// this helps maintain reasonable effectiveness of meshlet data and reduces scoring cost
+			if (extra < best_extra || score < best_score)
+			{
+				best_triangle = triangle;
+				best_extra = extra;
+				best_score = score;
+			}
+		}
+	}
+
+	if (out_extra)
+		*out_extra = best_extra;
+
+	return best_triangle;
+}
+
 struct KDNode
 {
 	union
@@ -471,6 +544,8 @@ size_t meshopt_buildMeshlets(meshopt_Meshlet* meshlets, unsigned int* meshlet_ve
 	assert(max_triangles >= 1 && max_triangles <= kMeshletMaxTriangles);
 	assert(max_triangles % 4 == 0); // ensures the caller will compute output space properly as index data is 4b aligned
 
+	assert(cone_weight >= 0 && cone_weight <= 1);
+
 	meshopt_Allocator allocator;
 
 	TriangleAdjacency2 adjacency = {};
@@ -511,65 +586,18 @@ size_t meshopt_buildMeshlets(meshopt_Meshlet* meshlets, unsigned int* meshlet_ve
 
 	for (;;)
 	{
-		unsigned int best_triangle = ~0u;
-		unsigned int best_extra = 5;
-		float best_score = FLT_MAX;
-
 		Cone meshlet_cone = getMeshletCone(meshlet_cone_acc, meshlet.triangle_count);
 
-		for (size_t i = 0; i < meshlet.vertex_count; ++i)
-		{
-			unsigned int index = meshlet_vertices[meshlet.vertex_offset + i];
-
-			unsigned int* neighbours = &adjacency.data[0] + adjacency.offsets[index];
-			size_t neighbours_size = adjacency.counts[index];
-
-			for (size_t j = 0; j < neighbours_size; ++j)
-			{
-				unsigned int triangle = neighbours[j];
-				assert(!emitted_flags[triangle]);
-
-				unsigned int a = indices[triangle * 3 + 0], b = indices[triangle * 3 + 1], c = indices[triangle * 3 + 2];
-				assert(a < vertex_count && b < vertex_count && c < vertex_count);
-
-				unsigned int extra = (used[a] == 0xff) + (used[b] == 0xff) + (used[c] == 0xff);
-
-				// triangles that don't add new vertices to meshlets are max. priority
-				if (extra != 0)
-				{
-					// artificially increase the priority of dangling triangles as they're expensive to add to new meshlets
-					if (live_triangles[a] == 1 || live_triangles[b] == 1 || live_triangles[c] == 1)
-						extra = 0;
-
-					extra++;
-				}
-
-				// since topology-based priority is always more important than the score, we can skip scoring in some cases
-				if (extra > best_extra)
-					continue;
-
-				const Cone& tri_cone = triangles[triangle];
-
-				float distance2 =
-				    (tri_cone.px - meshlet_cone.px) * (tri_cone.px - meshlet_cone.px) +
-				    (tri_cone.py - meshlet_cone.py) * (tri_cone.py - meshlet_cone.py) +
-				    (tri_cone.pz - meshlet_cone.pz) * (tri_cone.pz - meshlet_cone.pz);
-
-				float spread = tri_cone.nx * meshlet_cone.nx + tri_cone.ny * meshlet_cone.ny + tri_cone.nz * meshlet_cone.nz;
+		unsigned int best_extra = 0;
+		unsigned int best_triangle = getNeighborTriangle(meshlet, &meshlet_cone, meshlet_vertices, indices, adjacency, triangles, live_triangles, used, meshlet_expected_radius, cone_weight, &best_extra);
 
-				float score = getMeshletScore(distance2, spread, cone_weight, meshlet_expected_radius);
-
-				// note that topology-based priority is always more important than the score
-				// this helps maintain reasonable effectiveness of meshlet data and reduces scoring cost
-				if (extra < best_extra || score < best_score)
-				{
-					best_triangle = triangle;
-					best_extra = extra;
-					best_score = score;
-				}
-			}
+		// if the best triangle doesn't fit into current meshlet, the spatial scoring we've used is not very meaningful, so we re-select using topological scoring
+		if (best_triangle != ~0u && (meshlet.vertex_count + best_extra > max_vertices || meshlet.triangle_count >= max_triangles))
+		{
+			best_triangle = getNeighborTriangle(meshlet, NULL, meshlet_vertices, indices, adjacency, triangles, live_triangles, used, meshlet_expected_radius, 0.f, NULL);
 		}
 
+		// when we run out of neighboring triangles we need to switch to spatial search; we currently just pick the closest triangle irrespective of connectivity
 		if (best_triangle == ~0u)
 		{
 			float position[3] = {meshlet_cone.px, meshlet_cone.py, meshlet_cone.pz};
@@ -604,16 +632,16 @@ size_t meshopt_buildMeshlets(meshopt_Meshlet* meshlets, unsigned int* meshlet_ve
 		{
 			unsigned int index = indices[best_triangle * 3 + k];
 
-			unsigned int* neighbours = &adjacency.data[0] + adjacency.offsets[index];
-			size_t neighbours_size = adjacency.counts[index];
+			unsigned int* neighbors = &adjacency.data[0] + adjacency.offsets[index];
+			size_t neighbors_size = adjacency.counts[index];
 
-			for (size_t i = 0; i < neighbours_size; ++i)
+			for (size_t i = 0; i < neighbors_size; ++i)
 			{
-				unsigned int tri = neighbours[i];
+				unsigned int tri = neighbors[i];
 
 				if (tri == best_triangle)
 				{
-					neighbours[i] = neighbours[neighbours_size - 1];
+					neighbors[i] = neighbors[neighbors_size - 1];
 					adjacency.counts[index]--;
 					break;
 				}

3rdparty/meshoptimizer/src/meshoptimizer.h

@@ -332,7 +332,7 @@ enum
  *
  * destination must contain enough space for the target index buffer, worst case is index_count elements (*not* target_index_count)!
  * vertex_positions should have float3 position in the first 12 bytes of each vertex
- * target_error represents the error relative to mesh extents that can be tolerated, e.g. 0.01 = 1% deformation
+ * target_error represents the error relative to mesh extents that can be tolerated, e.g. 0.01 = 1% deformation; value range [0..1]
  * options must be a bitmask composed of meshopt_SimplifyX options; 0 is a safe default
  * result_error can be NULL; when it's not NULL, it will contain the resulting (relative) error after simplification
  */
@@ -348,7 +348,7 @@ MESHOPTIMIZER_API size_t meshopt_simplify(unsigned int* destination, const unsig
  *
  * destination must contain enough space for the target index buffer, worst case is index_count elements (*not* target_index_count)!
  * vertex_positions should have float3 position in the first 12 bytes of each vertex
- * target_error represents the error relative to mesh extents that can be tolerated, e.g. 0.01 = 1% deformation
+ * target_error represents the error relative to mesh extents that can be tolerated, e.g. 0.01 = 1% deformation; value range [0..1]
  * result_error can be NULL; when it's not NULL, it will contain the resulting (relative) error after simplification
  */
 MESHOPTIMIZER_EXPERIMENTAL size_t meshopt_simplifySloppy(unsigned int* destination, const unsigned int* indices, size_t index_count, const float* vertex_positions, size_t vertex_count, size_t vertex_positions_stride, size_t target_index_count, float target_error, float* result_error);

3rdparty/meshoptimizer/src/vcacheoptimizer.cpp

@@ -110,7 +110,7 @@ static unsigned int getNextVertexDeadEnd(const unsigned int* dead_end, unsigned
 	return ~0u;
 }
 
-static unsigned int getNextVertexNeighbour(const unsigned int* next_candidates_begin, const unsigned int* next_candidates_end, const unsigned int* live_triangles, const unsigned int* cache_timestamps, unsigned int timestamp, unsigned int cache_size)
+static unsigned int getNextVertexNeighbor(const unsigned int* next_candidates_begin, const unsigned int* next_candidates_end, const unsigned int* live_triangles, const unsigned int* cache_timestamps, unsigned int timestamp, unsigned int cache_size)
 {
 	unsigned int best_candidate = ~0u;
 	int best_priority = -1;
@@ -281,16 +281,16 @@ void meshopt_optimizeVertexCacheTable(unsigned int* destination, const unsigned
 		{
 			unsigned int index = indices[current_triangle * 3 + k];
 
-			unsigned int* neighbours = &adjacency.data[0] + adjacency.offsets[index];
-			size_t neighbours_size = adjacency.counts[index];
+			unsigned int* neighbors = &adjacency.data[0] + adjacency.offsets[index];
+			size_t neighbors_size = adjacency.counts[index];
 
-			for (size_t i = 0; i < neighbours_size; ++i)
+			for (size_t i = 0; i < neighbors_size; ++i)
 			{
-				unsigned int tri = neighbours[i];
+				unsigned int tri = neighbors[i];
 
 				if (tri == current_triangle)
 				{
-					neighbours[i] = neighbours[neighbours_size - 1];
+					neighbors[i] = neighbors[neighbors_size - 1];
 					adjacency.counts[index]--;
 					break;
 				}
@@ -314,10 +314,10 @@ void meshopt_optimizeVertexCacheTable(unsigned int* destination, const unsigned
 			vertex_scores[index] = score;
 
 			// update scores of vertex triangles
-			const unsigned int* neighbours_begin = &adjacency.data[0] + adjacency.offsets[index];
-			const unsigned int* neighbours_end = neighbours_begin + adjacency.counts[index];
+			const unsigned int* neighbors_begin = &adjacency.data[0] + adjacency.offsets[index];
+			const unsigned int* neighbors_end = neighbors_begin + adjacency.counts[index];
 
-			for (const unsigned int* it = neighbours_begin; it != neighbours_end; ++it)
+			for (const unsigned int* it = neighbors_begin; it != neighbors_end; ++it)
 			{
 				unsigned int tri = *it;
 				assert(!emitted_flags[tri]);
@@ -412,11 +412,11 @@ void meshopt_optimizeVertexCacheFifo(unsigned int* destination, const unsigned i
 	{
 		const unsigned int* next_candidates_begin = &dead_end[0] + dead_end_top;
 
-		// emit all vertex neighbours
-		const unsigned int* neighbours_begin = &adjacency.data[0] + adjacency.offsets[current_vertex];
-		const unsigned int* neighbours_end = neighbours_begin + adjacency.counts[current_vertex];
+		// emit all vertex neighbors
+		const unsigned int* neighbors_begin = &adjacency.data[0] + adjacency.offsets[current_vertex];
+		const unsigned int* neighbors_end = neighbors_begin + adjacency.counts[current_vertex];
 
-		for (const unsigned int* it = neighbours_begin; it != neighbours_end; ++it)
+		for (const unsigned int* it = neighbors_begin; it != neighbors_end; ++it)
 		{
 			unsigned int triangle = *it;
 
@@ -461,7 +461,7 @@ void meshopt_optimizeVertexCacheFifo(unsigned int* destination, const unsigned i
 		const unsigned int* next_candidates_end = &dead_end[0] + dead_end_top;
 
 		// get next vertex
-		current_vertex = getNextVertexNeighbour(next_candidates_begin, next_candidates_end, &live_triangles[0], &cache_timestamps[0], timestamp, cache_size);
+		current_vertex = getNextVertexNeighbor(next_candidates_begin, next_candidates_end, &live_triangles[0], &cache_timestamps[0], timestamp, cache_size);
 
 		if (current_vertex == ~0u)
 		{