Merge pull request #65493 from V-Sekai/lod_scaling

Fixes LOD scaling issues on skinned meshes.

2 files changed, 40 insertions, 3 deletions

diff --git a/scene/resources/importer_mesh.cpp b/scene/resources/importer_mesh.cpp
index 0afca95de0..de3d502102 100644
--- a/scene/resources/importer_mesh.cpp
+++ b/scene/resources/importer_mesh.cpp
@@ -254,7 +254,20 @@ void ImporterMesh::set_surface_material(int p_surface, const Ref<Material> &p_ma
 	mesh.unref();
 }
 
-void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_split_angle) {
+#define VERTEX_SKIN_FUNC(bone_count, vert_idx, read_array, write_array, transform_array, bone_array, weight_array) \
+	Vector3 transformed_vert = Vector3();                                                                          \
+	for (unsigned int weight_idx = 0; weight_idx < bone_count; weight_idx++) {                                     \
+		int bone_idx = bone_array[vert_idx * bone_count + weight_idx];                                             \
+		float w = weight_array[vert_idx * bone_count + weight_idx];                                                \
+		if (w < FLT_EPSILON) {                                                                                     \
+			continue;                                                                                              \
+		}                                                                                                          \
+		ERR_FAIL_INDEX(bone_idx, static_cast<int>(transform_array.size()));                                        \
+		transformed_vert += transform_array[bone_idx].xform(read_array[vert_idx]) * w;                             \
+	}                                                                                                              \
+	write_array[vert_idx] = transformed_vert;
+
+void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_split_angle, Array p_bone_transform_array) {
 	if (!SurfaceTool::simplify_scale_func) {
 		return;
 	}
@@ -265,6 +278,12 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 		return;
 	}
 
+	LocalVector<Transform3D> bone_transform_vector;
+	for (int i = 0; i < p_bone_transform_array.size(); i++) {
+		ERR_FAIL_COND(p_bone_transform_array[i].get_type() != Variant::TRANSFORM3D);
+		bone_transform_vector.push_back(p_bone_transform_array[i]);
+	}
+
 	for (int i = 0; i < surfaces.size(); i++) {
 		if (surfaces[i].primitive != Mesh::PRIMITIVE_TRIANGLES) {
 			continue;
@@ -276,6 +295,8 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 		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];
+		Vector<int> bones = surfaces[i].arrays[RS::ARRAY_BONES];
+		Vector<float> weights = surfaces[i].arrays[RS::ARRAY_WEIGHTS];
 
 		unsigned int index_count = indices.size();
 		unsigned int vertex_count = vertices.size();
@@ -301,6 +322,22 @@ void ImporterMesh::generate_lods(float p_normal_merge_angle, float p_normal_spli
 			}
 		}
 
+		if (bones.size() > 0 && weights.size() && bone_transform_vector.size() > 0) {
+			Vector3 *vertices_ptrw = vertices.ptrw();
+
+			// Apply bone transforms to regular surface.
+			unsigned int bone_weight_length = surfaces[i].flags & Mesh::ARRAY_FLAG_USE_8_BONE_WEIGHTS ? 8 : 4;
+
+			const int *bo = bones.ptr();
+			const float *we = weights.ptr();
+
+			for (unsigned int j = 0; j < vertex_count; j++) {
+				VERTEX_SKIN_FUNC(bone_weight_length, j, vertices_ptr, vertices_ptrw, bone_transform_vector, bo, we)
+			}
+
+			vertices_ptr = vertices.ptr();
+		}
+
 		float normal_merge_threshold = Math::cos(Math::deg_to_rad(p_normal_merge_angle));
 		float normal_pre_split_threshold = Math::cos(Math::deg_to_rad(MIN(180.0f, p_normal_split_angle * 2.0f)));
 		float normal_split_threshold = Math::cos(Math::deg_to_rad(p_normal_split_angle));
@@ -1246,7 +1283,7 @@ void ImporterMesh::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_surface_name", "surface_idx", "name"), &ImporterMesh::set_surface_name);
 	ClassDB::bind_method(D_METHOD("set_surface_material", "surface_idx", "material"), &ImporterMesh::set_surface_material);
 
-	ClassDB::bind_method(D_METHOD("generate_lods", "normal_merge_angle", "normal_split_angle"), &ImporterMesh::generate_lods);
+	ClassDB::bind_method(D_METHOD("generate_lods", "normal_merge_angle", "normal_split_angle", "bone_transform_array"), &ImporterMesh::generate_lods);
 	ClassDB::bind_method(D_METHOD("get_mesh", "base_mesh"), &ImporterMesh::get_mesh, DEFVAL(Ref<ArrayMesh>()));
 	ClassDB::bind_method(D_METHOD("clear"), &ImporterMesh::clear);
 
diff --git a/scene/resources/importer_mesh.h b/scene/resources/importer_mesh.h
index dce2638c19..088a77edd1 100644
--- a/scene/resources/importer_mesh.h
+++ b/scene/resources/importer_mesh.h
@@ -112,7 +112,7 @@ public:
 
 	void set_surface_material(int p_surface, const Ref<Material> &p_material);
 
-	void generate_lods(float p_normal_merge_angle, float p_normal_split_angle);
+	void generate_lods(float p_normal_merge_angle, float p_normal_split_angle, Array p_skin_pose_transform_array);
 
 	void create_shadow_mesh();
 	Ref<ImporterMesh> get_shadow_mesh() const;