Add drag-and-drop support for materials in 3D

Add mesh surface picking for material drag & drop, show drag info label

editor/plugins/node_3d_editor_plugin.cpp

@@ -514,7 +514,7 @@ void Node3DEditorViewport::_select_clicked(bool p_allow_locked) {
 	}
 }
 
-ObjectID Node3DEditorViewport::_select_ray(const Point2 &p_pos) {
+ObjectID Node3DEditorViewport::_select_ray(const Point2 &p_pos) const {
 	Vector3 ray = _get_ray(p_pos);
 	Vector3 pos = _get_ray_pos(p_pos);
 	Vector2 shrinked_pos = p_pos / subviewport_container->get_stretch_shrink();
@@ -1259,7 +1259,9 @@ void Node3DEditorViewport::_surface_mouse_enter() {
 }
 
 void Node3DEditorViewport::_surface_mouse_exit() {
-	_remove_preview();
+	_remove_preview_node();
+	_reset_preview_material();
+	_remove_preview_material();
 }
 
 void Node3DEditorViewport::_surface_focus_enter() {
@@ -2702,6 +2704,13 @@ void Node3DEditorViewport::_notification(int p_what) {
 			cinema_label->add_theme_style_override("normal", gui_base->get_theme_stylebox(SNAME("Information3dViewport"), SNAME("EditorStyles")));
 			locked_label->add_theme_style_override("normal", gui_base->get_theme_stylebox(SNAME("Information3dViewport"), SNAME("EditorStyles")));
 		} break;
+
+		case NOTIFICATION_DRAG_END: {
+			// Clear preview material when dropped outside applicable object.
+			if (spatial_editor->get_preview_material().is_valid() && !is_drag_successful()) {
+				_remove_preview_material();
+			}
+		} break;
 	}
 }
 
@@ -3793,7 +3802,7 @@ Node *Node3DEditorViewport::_sanitize_preview_node(Node *p_node) const {
 	return p_node;
 }
 
-void Node3DEditorViewport::_create_preview(const Vector<String> &files) const {
+void Node3DEditorViewport::_create_preview_node(const Vector<String> &files) const {
 	for (int i = 0; i < files.size(); i++) {
 		String path = files[i];
 		Ref<Resource> res = ResourceLoader::load(path);
@@ -3820,7 +3829,7 @@ void Node3DEditorViewport::_create_preview(const Vector<String> &files) const {
 	*preview_bounds = _calculate_spatial_bounds(preview_node);
 }
 
-void Node3DEditorViewport::_remove_preview() {
+void Node3DEditorViewport::_remove_preview_node() {
 	if (preview_node->get_parent()) {
 		for (int i = preview_node->get_child_count() - 1; i >= 0; i--) {
 			Node *node = preview_node->get_child(i);
@@ -3831,6 +3840,106 @@ void Node3DEditorViewport::_remove_preview() {
 	}
 }
 
+bool Node3DEditorViewport::_apply_preview_material(ObjectID p_target, const Point2 &p_point) const {
+	_reset_preview_material();
+
+	if (p_target.is_null()) {
+		return false;
+	}
+
+	spatial_editor->set_preview_material_target(p_target);
+
+	Object *target_inst = ObjectDB::get_instance(p_target);
+
+	bool is_ctrl = Input::get_singleton()->is_key_pressed(Key::CTRL);
+
+	MeshInstance3D *mesh_instance = Object::cast_to<MeshInstance3D>(target_inst);
+	if (is_ctrl && mesh_instance) {
+		Ref<Mesh> mesh = mesh_instance->get_mesh();
+		int surface_count = mesh->get_surface_count();
+
+		Vector3 world_ray = _get_ray(p_point);
+		Vector3 world_pos = _get_ray_pos(p_point);
+
+		int closest_surface = -1;
+		float closest_dist = 1e20;
+
+		Transform3D gt = mesh_instance->get_global_transform();
+
+		Transform3D ai = gt.affine_inverse();
+		Vector3 xform_ray = ai.basis.xform(world_ray).normalized();
+		Vector3 xform_pos = ai.xform(world_pos);
+
+		for (int surface = 0; surface < surface_count; surface++) {
+			Ref<TriangleMesh> surface_mesh = mesh->generate_surface_triangle_mesh(surface);
+
+			Vector3 rpos, rnorm;
+			if (surface_mesh->intersect_ray(xform_pos, xform_ray, rpos, rnorm)) {
+				Vector3 hitpos = gt.xform(rpos);
+
+				const real_t dist = world_pos.distance_to(hitpos);
+
+				if (dist < 0) {
+					continue;
+				}
+
+				if (dist < closest_dist) {
+					closest_surface = surface;
+					closest_dist = dist;
+				}
+			}
+		}
+
+		if (closest_surface == -1) {
+			return false;
+		}
+
+		if (spatial_editor->get_preview_material() != mesh_instance->get_surface_override_material(closest_surface)) {
+			spatial_editor->set_preview_material_surface(closest_surface);
+			spatial_editor->set_preview_reset_material(mesh_instance->get_surface_override_material(closest_surface));
+			mesh_instance->set_surface_override_material(closest_surface, spatial_editor->get_preview_material());
+		}
+
+		return true;
+	}
+
+	GeometryInstance3D *geometry_instance = Object::cast_to<GeometryInstance3D>(target_inst);
+	if (geometry_instance && spatial_editor->get_preview_material() != geometry_instance->get_material_override()) {
+		spatial_editor->set_preview_reset_material(geometry_instance->get_material_override());
+		geometry_instance->set_material_override(spatial_editor->get_preview_material());
+		return true;
+	}
+
+	return false;
+}
+
+void Node3DEditorViewport::_reset_preview_material() const {
+	ObjectID last_target = spatial_editor->get_preview_material_target();
+	if (last_target.is_null()) {
+		return;
+	}
+	Object *last_target_inst = ObjectDB::get_instance(last_target);
+
+	MeshInstance3D *mesh_instance = Object::cast_to<MeshInstance3D>(last_target_inst);
+	GeometryInstance3D *geometry_instance = Object::cast_to<GeometryInstance3D>(last_target_inst);
+	if (mesh_instance && spatial_editor->get_preview_material_surface() != -1) {
+		mesh_instance->set_surface_override_material(spatial_editor->get_preview_material_surface(), spatial_editor->get_preview_reset_material());
+		spatial_editor->set_preview_material_surface(-1);
+	} else if (geometry_instance) {
+		geometry_instance->set_material_override(spatial_editor->get_preview_reset_material());
+	}
+}
+
+void Node3DEditorViewport::_remove_preview_material() {
+	preview_material_label->hide();
+	preview_material_label_desc->hide();
+
+	spatial_editor->set_preview_material(Ref<Material>());
+	spatial_editor->set_preview_reset_material(Ref<Material>());
+	spatial_editor->set_preview_material_target(ObjectID());
+	spatial_editor->set_preview_material_surface(-1);
+}
+
 bool Node3DEditorViewport::_cyclical_dependency_exists(const String &p_target_scene_path, Node *p_desired_node) {
 	if (p_desired_node->get_scene_file_path() == p_target_scene_path) {
 		return true;
@@ -3929,7 +4038,26 @@ bool Node3DEditorViewport::_create_instance(Node *parent, String &path, const Po
 }
 
 void Node3DEditorViewport::_perform_drop_data() {
-	_remove_preview();
+	if (spatial_editor->get_preview_material_target().is_valid()) {
+		GeometryInstance3D *geometry_instance = Object::cast_to<GeometryInstance3D>(ObjectDB::get_instance(spatial_editor->get_preview_material_target()));
+		MeshInstance3D *mesh_instance = Object::cast_to<MeshInstance3D>(ObjectDB::get_instance(spatial_editor->get_preview_material_target()));
+		if (mesh_instance && spatial_editor->get_preview_material_surface() != -1) {
+			editor_data->get_undo_redo().create_action(vformat(TTR("Set Surface %d Override Material"), spatial_editor->get_preview_material_surface()));
+			editor_data->get_undo_redo().add_do_method(geometry_instance, "set_surface_override_material", spatial_editor->get_preview_material_surface(), spatial_editor->get_preview_material());
+			editor_data->get_undo_redo().add_undo_method(geometry_instance, "set_surface_override_material", spatial_editor->get_preview_material_surface(), spatial_editor->get_preview_reset_material());
+			editor_data->get_undo_redo().commit_action();
+		} else if (geometry_instance) {
+			editor_data->get_undo_redo().create_action(TTR("Set Material Override"));
+			editor_data->get_undo_redo().add_do_method(geometry_instance, "set_material_override", spatial_editor->get_preview_material());
+			editor_data->get_undo_redo().add_undo_method(geometry_instance, "set_material_override", spatial_editor->get_preview_reset_material());
+			editor_data->get_undo_redo().commit_action();
+		}
+
+		_remove_preview_material();
+		return;
+	}
+
+	_remove_preview_node();
 
 	Vector<String> error_files;
 
@@ -3967,7 +4095,7 @@ void Node3DEditorViewport::_perform_drop_data() {
 bool Node3DEditorViewport::can_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) const {
 	bool can_instantiate = false;
 
-	if (!preview_node->is_inside_tree()) {
+	if (!preview_node->is_inside_tree() && spatial_editor->get_preview_material().is_null()) {
 		Dictionary d = p_data;
 		if (d.has("type") && (String(d["type"]) == "files")) {
 			Vector<String> files = d["files"];
@@ -3976,40 +4104,78 @@ bool Node3DEditorViewport::can_drop_data_fw(const Point2 &p_point, const Variant
 			ResourceLoader::get_recognized_extensions_for_type("PackedScene", &scene_extensions);
 			List<String> mesh_extensions;
 			ResourceLoader::get_recognized_extensions_for_type("Mesh", &mesh_extensions);
+			List<String> material_extensions;
+			ResourceLoader::get_recognized_extensions_for_type("Material", &material_extensions);
+			List<String> texture_extensions;
+			ResourceLoader::get_recognized_extensions_for_type("Texture", &texture_extensions);
 
 			for (int i = 0; i < files.size(); i++) {
 				// Check if dragged files with mesh or scene extension can be created at least once.
-				if (mesh_extensions.find(files[i].get_extension()) || scene_extensions.find(files[i].get_extension())) {
+				if (mesh_extensions.find(files[i].get_extension()) ||
+						scene_extensions.find(files[i].get_extension()) ||
+						material_extensions.find(files[i].get_extension()) ||
+						texture_extensions.find(files[i].get_extension())) {
 					Ref<Resource> res = ResourceLoader::load(files[i]);
 					if (res.is_null()) {
 						continue;
 					}
 					Ref<PackedScene> scn = res;
+					Ref<Material> mat = res;
+					Ref<Texture2D> tex = res;
 					if (scn.is_valid()) {
 						Node *instantiated_scene = scn->instantiate(PackedScene::GEN_EDIT_STATE_INSTANCE);
 						if (!instantiated_scene) {
 							continue;
 						}
 						memdelete(instantiated_scene);
+					} else if (mat.is_valid()) {
+						Ref<BaseMaterial3D> base_mat = res;
+						Ref<ShaderMaterial> shader_mat = res;
+
+						if (base_mat.is_null() && !shader_mat.is_null()) {
+							break;
+						}
+
+						spatial_editor->set_preview_material(mat);
+						break;
+					} else if (tex.is_valid()) {
+						Ref<StandardMaterial3D> new_mat = memnew(StandardMaterial3D);
+						new_mat->set_texture(BaseMaterial3D::TEXTURE_ALBEDO, tex);
+
+						spatial_editor->set_preview_material(new_mat);
+						break;
+					} else {
+						continue;
 					}
 					can_instantiate = true;
 					break;
 				}
 			}
 			if (can_instantiate) {
-				_create_preview(files);
+				_create_preview_node(files);
 			}
 		}
 	} else {
-		can_instantiate = true;
+		if (preview_node->is_inside_tree()) {
+			can_instantiate = true;
+		}
 	}
 
 	if (can_instantiate) {
 		Transform3D global_transform = Transform3D(Basis(), _get_instance_position(p_point));
 		preview_node->set_global_transform(global_transform);
+		return true;
+	}
+
+	if (spatial_editor->get_preview_material().is_valid()) {
+		preview_material_label->show();
+		preview_material_label_desc->show();
+
+		ObjectID new_preview_material_target = _select_ray(p_point);
+		return _apply_preview_material(new_preview_material_target, p_point);
 	}
 
-	return can_instantiate;
+	return false;
 }
 
 void Node3DEditorViewport::drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) {
@@ -4047,7 +4213,7 @@ void Node3DEditorViewport::drop_data_fw(const Point2 &p_point, const Variant &p_
 	} else {
 		accept->set_text(TTR("Cannot drag and drop into multiple selected nodes."));
 		accept->popup_centered();
-		_remove_preview();
+		_remove_preview_node();
 		return;
 	}
 
@@ -4698,6 +4864,23 @@ Node3DEditorViewport::Node3DEditorViewport(Node3DEditor *p_spatial_editor, int p
 	zoom_limit_label->hide();
 	surface->add_child(zoom_limit_label);
 
+	preview_material_label = memnew(Label);
+	preview_material_label->set_anchors_and_offsets_preset(LayoutPreset::PRESET_BOTTOM_LEFT);
+	preview_material_label->set_offset(Side::SIDE_TOP, -70 * EDSCALE);
+	preview_material_label->set_text(TTR("Overriding material..."));
+	preview_material_label->add_theme_color_override("font_color", Color(1, 1, 1, 1));
+	preview_material_label->hide();
+	surface->add_child(preview_material_label);
+
+	preview_material_label_desc = memnew(Label);
+	preview_material_label_desc->set_anchors_and_offsets_preset(LayoutPreset::PRESET_BOTTOM_LEFT);
+	preview_material_label_desc->set_offset(Side::SIDE_TOP, -50 * EDSCALE);
+	preview_material_label_desc->set_text(TTR("Drag and drop to override the material of any geometry node.\nHold Ctrl when dropping to override a specific surface."));
+	preview_material_label_desc->add_theme_color_override("font_color", Color(0.8, 0.8, 0.8, 1));
+	preview_material_label_desc->add_theme_constant_override("line_spacing", 0);
+	preview_material_label_desc->hide();
+	surface->add_child(preview_material_label_desc);
+
 	frame_time_gradient = memnew(Gradient);
 	// The color is set when the theme changes.
 	frame_time_gradient->add_point(0.5, Color());
@@ -8131,7 +8314,6 @@ void fragment() {
 		_preview_settings_changed();
 	}
 }
-
 Node3DEditor::~Node3DEditor() {
 	memdelete(preview_node);
 }

editor/plugins/node_3d_editor_plugin.h

@@ -227,6 +227,9 @@ private:
 	Label *locked_label = nullptr;
 	Label *zoom_limit_label = nullptr;
 
+	Label *preview_material_label = nullptr;
+	Label *preview_material_label_desc = nullptr;
+
 	VBoxContainer *top_right_vbox = nullptr;
 	ViewportRotationControl *rotation_control = nullptr;
 	Gradient *frame_time_gradient = nullptr;
@@ -244,7 +247,7 @@ private:
 	void _compute_edit(const Point2 &p_point);
 	void _clear_selected();
 	void _select_clicked(bool p_allow_locked);
-	ObjectID _select_ray(const Point2 &p_pos);
+	ObjectID _select_ray(const Point2 &p_pos) const;
 	void _find_items_at_pos(const Point2 &p_pos, Vector<_RayResult> &r_results, bool p_include_locked);
 	Vector3 _get_ray_pos(const Vector2 &p_pos) const;
 	Vector3 _get_ray(const Vector2 &p_pos) const;
@@ -272,6 +275,7 @@ private:
 	float get_fov() const;
 
 	ObjectID clicked;
+	ObjectID material_target;
 	Vector<_RayResult> selection_results;
 	bool clicked_wants_append = false;
 	bool selection_in_progress = false;
@@ -399,8 +403,11 @@ private:
 
 	Node *_sanitize_preview_node(Node *p_node) const;
 
-	void _create_preview(const Vector<String> &files) const;
-	void _remove_preview();
+	void _create_preview_node(const Vector<String> &files) const;
+	void _remove_preview_node();
+	bool _apply_preview_material(ObjectID p_target, const Point2 &p_point) const;
+	void _reset_preview_material() const;
+	void _remove_preview_material();
 	bool _cyclical_dependency_exists(const String &p_target_scene_path, Node *p_desired_node);
 	bool _create_instance(Node *parent, String &path, const Point2 &p_point);
 	void _perform_drop_data();
@@ -593,6 +600,11 @@ private:
 	Node3D *preview_node = nullptr;
 	AABB preview_bounds;
 
+	Ref<Material> preview_material;
+	Ref<Material> preview_reset_material;
+	ObjectID preview_material_target;
+	int preview_material_surface = -1;
+
 	struct Gizmo {
 		bool visible = false;
 		real_t scale = 0;
@@ -851,6 +863,15 @@ public:
 
 	void set_can_preview(Camera3D *p_preview);
 
+	void set_preview_material(Ref<Material> p_material) { preview_material = p_material; }
+	Ref<Material> get_preview_material() { return preview_material; }
+	void set_preview_reset_material(Ref<Material> p_material) { preview_reset_material = p_material; }
+	Ref<Material> get_preview_reset_material() const { return preview_reset_material; }
+	void set_preview_material_target(ObjectID p_object_id) { preview_material_target = p_object_id; }
+	ObjectID get_preview_material_target() const { return preview_material_target; }
+	void set_preview_material_surface(int p_surface) { preview_material_surface = p_surface; }
+	int get_preview_material_surface() const { return preview_material_surface; }
+
 	Node3DEditorViewport *get_editor_viewport(int p_idx) {
 		ERR_FAIL_INDEX_V(p_idx, static_cast<int>(VIEWPORTS_COUNT), nullptr);
 		return viewports[p_idx];

scene/resources/mesh.cpp

@@ -260,6 +260,64 @@ Ref<TriangleMesh> Mesh::generate_triangle_mesh() const {
 	return triangle_mesh;
 }
 
+Ref<TriangleMesh> Mesh::generate_surface_triangle_mesh(int p_surface) const {
+	ERR_FAIL_INDEX_V(p_surface, get_surface_count(), Ref<TriangleMesh>());
+
+	if (surface_triangle_meshes.size() != get_surface_count()) {
+		surface_triangle_meshes.resize(get_surface_count());
+	}
+
+	if (surface_triangle_meshes[p_surface].is_valid()) {
+		return surface_triangle_meshes[p_surface];
+	}
+
+	int facecount = 0;
+
+	if (surface_get_primitive_type(p_surface) != PRIMITIVE_TRIANGLES) {
+		return Ref<TriangleMesh>();
+	}
+
+	if (surface_get_format(p_surface) & ARRAY_FORMAT_INDEX) {
+		facecount += surface_get_array_index_len(p_surface);
+	} else {
+		facecount += surface_get_array_len(p_surface);
+	}
+
+	Vector<Vector3> faces;
+	faces.resize(facecount);
+	Vector3 *facesw = faces.ptrw();
+
+	Array a = surface_get_arrays(p_surface);
+	ERR_FAIL_COND_V(a.is_empty(), Ref<TriangleMesh>());
+
+	int vc = surface_get_array_len(p_surface);
+	Vector<Vector3> vertices = a[ARRAY_VERTEX];
+	const Vector3 *vr = vertices.ptr();
+	int widx = 0;
+
+	if (surface_get_format(p_surface) & ARRAY_FORMAT_INDEX) {
+		int ic = surface_get_array_index_len(p_surface);
+		Vector<int> indices = a[ARRAY_INDEX];
+		const int *ir = indices.ptr();
+
+		for (int j = 0; j < ic; j++) {
+			int index = ir[j];
+			facesw[widx++] = vr[index];
+		}
+
+	} else {
+		for (int j = 0; j < vc; j++) {
+			facesw[widx++] = vr[j];
+		}
+	}
+
+	Ref<TriangleMesh> triangle_mesh = Ref<TriangleMesh>(memnew(TriangleMesh));
+	triangle_mesh->create(faces);
+	surface_triangle_meshes.set(p_surface, triangle_mesh);
+
+	return triangle_mesh;
+}
+
 void Mesh::generate_debug_mesh_lines(Vector<Vector3> &r_lines) {
 	if (debug_lines.size() > 0) {
 		r_lines = debug_lines;
@@ -320,6 +378,14 @@ Vector<Face3> Mesh::get_faces() const {
 	return Vector<Face3>();
 }
 
+Vector<Face3> Mesh::get_surface_faces(int p_surface) const {
+	Ref<TriangleMesh> tm = generate_surface_triangle_mesh(p_surface);
+	if (tm.is_valid()) {
+		return tm->get_faces();
+	}
+	return Vector<Face3>();
+}
+
 Ref<Shape3D> Mesh::create_convex_shape(bool p_clean, bool p_simplify) const {
 	if (p_simplify) {
 		ConvexDecompositionSettings settings;

scene/resources/mesh.h

@@ -42,6 +42,7 @@ class Mesh : public Resource {
 	GDCLASS(Mesh, Resource);
 
 	mutable Ref<TriangleMesh> triangle_mesh; //cached
+	mutable Vector<Ref<TriangleMesh>> surface_triangle_meshes; //cached
 	mutable Vector<Vector3> debug_lines;
 	Size2i lightmap_size_hint;
 
@@ -161,7 +162,9 @@ public:
 	virtual AABB get_aabb() const;
 
 	Vector<Face3> get_faces() const;
+	Vector<Face3> get_surface_faces(int p_surface) const;
 	Ref<TriangleMesh> generate_triangle_mesh() const;
+	Ref<TriangleMesh> generate_surface_triangle_mesh(int p_surface) const;
 	void generate_debug_mesh_lines(Vector<Vector3> &r_lines);
 	void generate_debug_mesh_indices(Vector<Vector3> &r_points);