Allow automatic lod when importing 3D scenes with Static Lightmaps

Avoid the normal merge procedure when uv2s are different and makes generating LODs happen after the lightmap generation

editor/import/resource_importer_scene.cpp

@@ -1649,14 +1649,6 @@ void ResourceImporterScene::_generate_meshes(Node *p_node, const Dictionary &p_m
 					}
 				}
 
-				if (generate_lods) {
-					src_mesh_node->get_mesh()->generate_lods(merge_angle, split_angle);
-				}
-
-				if (create_shadow_meshes) {
-					src_mesh_node->get_mesh()->create_shadow_mesh();
-				}
-
 				if (bake_lightmaps) {
 					Transform3D xf;
 					Node3D *n = src_mesh_node;
@@ -1689,6 +1681,14 @@ void ResourceImporterScene::_generate_meshes(Node *p_node, const Dictionary &p_m
 					}
 				}
 
+				if (generate_lods) {
+					src_mesh_node->get_mesh()->generate_lods(merge_angle, split_angle);
+				}
+
+				if (create_shadow_meshes) {
+					src_mesh_node->get_mesh()->create_shadow_mesh();
+				}
+
 				if (!save_to_file.is_empty()) {
 					Ref<Mesh> existing = Ref<Resource>(ResourceCache::get(save_to_file));
 					if (existing.is_valid()) {

scene/resources/importer_mesh.cpp

@@ -275,6 +275,7 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 		PackedInt32Array indices = surfaces[i].arrays[RS::ARRAY_INDEX];
 		Vector<Vector3> normals = surfaces[i].arrays[RS::ARRAY_NORMAL];
 		Vector<Vector2> uvs = surfaces[i].arrays[RS::ARRAY_TEX_UV];
+		Vector<Vector2> uv2s = surfaces[i].arrays[RS::ARRAY_TEX_UV2];
 
 		unsigned int index_count = indices.size();
 		unsigned int vertex_count = vertices.size();
@@ -313,6 +314,7 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 		LocalVector<Vector3> merged_normals;
 		LocalVector<int> merged_normals_counts;
 		const Vector2 *uvs_ptr = uvs.ptr();
+		const Vector2 *uv2s_ptr = uv2s.ptr();
 
 		for (unsigned int j = 0; j < vertex_count; j++) {
 			const Vector3 &v = vertices_ptr[j];
@@ -327,8 +329,10 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 				for (unsigned int k = 0; k < close_verts.size(); k++) {
 					const Pair<int, int> &idx = close_verts[k];
 
-					// TODO check more attributes?
-					if ((!uvs_ptr || uvs_ptr[j].distance_squared_to(uvs_ptr[idx.second]) < CMP_EPSILON2) && normals[idx.second].dot(n) > normal_merge_threshold) {
+					bool is_uvs_close = (!uvs_ptr || uvs_ptr[j].distance_squared_to(uvs_ptr[idx.second]) < CMP_EPSILON2);
+					bool is_uv2s_close = (!uv2s_ptr || uv2s_ptr[j].distance_squared_to(uv2s_ptr[idx.second]) < CMP_EPSILON2);
+					bool is_normals_close = normals[idx.second].dot(n) > normal_merge_threshold;
+					if (is_uvs_close && is_uv2s_close && is_normals_close) {
 						vertex_remap.push_back(idx.first);
 						merged_normals[idx.first] += normals[idx.second];
 						merged_normals_counts[idx.first]++;