Improved 3D Asset Import Dialog material editing

Implements [7238](godotengine/godot-proposals#7238) (for the most part).

* Ability to select nodes, meshes or materials by clicking.
* Moved mesh/material previews to the inspector area.
* Ability to override materials and edit them directly in the inspector.
* By default, shows overridden materials in the imported scene, with a button to disable them and show original materials.
* Keeps compatibility with the old override format.

Co-authored-by: Juan Linietsky <[email protected]>

Author: lyuma

core/math/triangle_mesh.cpp

@@ -107,13 +107,13 @@ void TriangleMesh::get_indices(Vector<int> *r_triangles_indices) const {
 void TriangleMesh::create(const Vector<Vector3> &p_faces, const Vector<int32_t> &p_surface_indices) {
 	valid = false;
 
-	ERR_FAIL_COND(p_surface_indices.size() && p_surface_indices.size() != p_faces.size());
-
 	int fc = p_faces.size();
 	ERR_FAIL_COND(!fc || ((fc % 3) != 0));
 	fc /= 3;
 	triangles.resize(fc);
 
+	ERR_FAIL_COND(p_surface_indices.size() && p_surface_indices.size() != triangles.size());
+
 	bvh.resize(fc * 3); //will never be larger than this (todo make better)
 	BVH *bw = bvh.ptrw();
 

editor/editor_node.cpp

@@ -1575,7 +1575,7 @@ void EditorNode::save_resource(const Ref<Resource> &p_resource) {
 	if (path.is_resource_file() && !FileAccess::exists(path + ".import")) {
 		save_resource_in_path(p_resource, p_resource->get_path());
 	} else {
-		save_resource_as(p_resource);
+		save_resource_as(p_resource, "");
 	}
 }
 

editor/icons/MaterialSelect.svg

@@ -1617,6 +1617,7 @@ Node *ResourceImporterScene::_post_fix_node(Node *p_node, Node *p_root, HashMap<
 						}
 						if (!mat_id.is_empty() && p_material_data.has(mat_id)) {
 							Dictionary matdata = p_material_data[mat_id];
+							// Old style material, keep for compatibility.
 							if (matdata.has("use_external/enabled") && bool(matdata["use_external/enabled"]) && matdata.has("use_external/path")) {
 								String path = matdata["use_external/path"];
 								Ref<Material> external_mat = ResourceLoader::load(path);
@@ -1642,6 +1643,13 @@ Node *ResourceImporterScene::_post_fix_node(Node *p_node, Node *p_root, HashMap<
 									matdata["use_external/fallback_path"] = external_mat->get_path();
 								}
 							}
+							// New style custom material
+							if (matdata.has("custom")) {
+								Ref<Material> external_mat = matdata["custom"];
+								if (external_mat.is_valid()) {
+									m->set_surface_material(i, external_mat);
+								}
+							}
 						}
 					}
 				}
@@ -2168,9 +2176,11 @@ void ResourceImporterScene::get_internal_import_options(InternalImportCategory p
 			r_options->push_back(ImportOption(PropertyInfo(Variant::FLOAT, "lods/normal_merge_angle", PROPERTY_HINT_RANGE, "0,180,1,degrees"), 20.0f));
 		} break;
 		case INTERNAL_IMPORT_CATEGORY_MATERIAL: {
-			r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL, "use_external/enabled", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_UPDATE_ALL_IF_MODIFIED), false));
-			r_options->push_back(ImportOption(PropertyInfo(Variant::STRING, "use_external/path", PROPERTY_HINT_FILE, "*.material,*.res,*.tres"), ""));
-			r_options->push_back(ImportOption(PropertyInfo(Variant::STRING, "use_external/fallback_path", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NO_EDITOR), ""));
+			// Compatibility (hidden) settings.
+			r_options->push_back(ImportOption(PropertyInfo(Variant::BOOL, "use_external/enabled", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), false));
+			r_options->push_back(ImportOption(PropertyInfo(Variant::STRING, "use_external/path", PROPERTY_HINT_FILE, "*.material,*.res,*.tres", PROPERTY_USAGE_NONE), ""));
+			r_options->push_back(ImportOption(PropertyInfo(Variant::STRING, "use_external/fallback_path", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), ""));
+			r_options->push_back(ImportOption(PropertyInfo(Variant::OBJECT, "custom", PROPERTY_HINT_RESOURCE_TYPE, "BaseMaterial3D,ShaderMaterial"), Ref<Material>()));
 		} break;
 		case INTERNAL_IMPORT_CATEGORY_ANIMATION: {
 			r_options->push_back(ImportOption(PropertyInfo(Variant::INT, "settings/loop_mode", PROPERTY_HINT_ENUM, "None,Linear,Pingpong"), 0));