Merge pull request #48915 from lyuma/gltf_mesh_nodes_bones

gltf: Fix mesh nodes which are also bones.

5 files changed, 121 insertions, 138 deletions

diff --git a/modules/gltf/doc_classes/GLTFNode.xml b/modules/gltf/doc_classes/GLTFNode.xml
index 5b7d4fadec..af7be55e4b 100644
--- a/modules/gltf/doc_classes/GLTFNode.xml
+++ b/modules/gltf/doc_classes/GLTFNode.xml
@@ -13,8 +13,6 @@
 		</member>
 		<member name="children" type="PackedInt32Array" setter="set_children" getter="get_children" default="PackedInt32Array(  )">
 		</member>
-		<member name="fake_joint_parent" type="int" setter="set_fake_joint_parent" getter="get_fake_joint_parent" default="-1">
-		</member>
 		<member name="height" type="int" setter="set_height" getter="get_height" default="-1">
 		</member>
 		<member name="joint" type="bool" setter="set_joint" getter="get_joint" default="false">
diff --git a/modules/gltf/gltf_document.cpp b/modules/gltf/gltf_document.cpp
index ac76506b87..abac0a2e17 100644
--- a/modules/gltf/gltf_document.cpp
+++ b/modules/gltf/gltf_document.cpp
@@ -2821,8 +2821,8 @@ Error GLTFDocument::_parse_meshes(Ref<GLTFState> state) {
 				}
 				blend_weights.write[j] = weights[j];
 			}
-			mesh->set_blend_weights(blend_weights);
 		}
+		mesh->set_blend_weights(blend_weights);
 		mesh->set_mesh(import_mesh);
 
 		state->meshes.push_back(mesh);
@@ -4108,81 +4108,10 @@ Error GLTFDocument::_reparent_non_joint_skeleton_subtrees(Ref<GLTFState> state,
 		subtree_set.get_members(subtree_nodes, subtree_root);
 
 		for (int subtree_i = 0; subtree_i < subtree_nodes.size(); ++subtree_i) {
-			ERR_FAIL_COND_V(_reparent_to_fake_joint(state, skeleton, subtree_nodes[subtree_i]), FAILED);
-
-			// We modified the tree, recompute all the heights
-			_compute_node_heights(state);
-		}
-	}
-
-	return OK;
-}
-
-Error GLTFDocument::_reparent_to_fake_joint(Ref<GLTFState> state, Ref<GLTFSkeleton> skeleton, const GLTFNodeIndex node_index) {
-	Ref<GLTFNode> node = state->nodes[node_index];
-
-	// Can we just "steal" this joint if it is just a spatial node?
-	if (node->skin < 0 && node->mesh < 0 && node->camera < 0) {
-		node->joint = true;
-		// Add the joint to the skeletons joints
-		skeleton->joints.push_back(node_index);
-		return OK;
-	}
-
-	GLTFNode *fake_joint = memnew(GLTFNode);
-	const GLTFNodeIndex fake_joint_index = state->nodes.size();
-	state->nodes.push_back(fake_joint);
-
-	// We better not be a joint, or we messed up in our logic
-	if (node->joint) {
-		return FAILED;
-	}
-
-	fake_joint->translation = node->translation;
-	fake_joint->rotation = node->rotation;
-	fake_joint->scale = node->scale;
-	fake_joint->xform = node->xform;
-	fake_joint->joint = true;
-
-	// We can use the exact same name here, because the joint will be inside a skeleton and not the scene
-	fake_joint->set_name(node->get_name());
-
-	// Clear the nodes transforms, since it will be parented to the fake joint
-	node->translation = Vector3(0, 0, 0);
-	node->rotation = Quat();
-	node->scale = Vector3(1, 1, 1);
-	node->xform = Transform();
-
-	// Transfer the node children to the fake joint
-	for (int child_i = 0; child_i < node->children.size(); ++child_i) {
-		Ref<GLTFNode> child = state->nodes[node->children[child_i]];
-		child->parent = fake_joint_index;
-	}
-
-	fake_joint->children = node->children;
-	node->children.clear();
-
-	// add the fake joint to the parent and remove the original joint
-	if (node->parent >= 0) {
-		Ref<GLTFNode> parent = state->nodes[node->parent];
-		parent->children.erase(node_index);
-		parent->children.push_back(fake_joint_index);
-		fake_joint->parent = node->parent;
-	}
-
-	// Add the node to the fake joint
-	fake_joint->children.push_back(node_index);
-	node->parent = fake_joint_index;
-	node->fake_joint_parent = fake_joint_index;
-
-	// Add the fake joint to the skeletons joints
-	skeleton->joints.push_back(fake_joint_index);
-
-	// Replace skin_skeletons with fake joints if we must.
-	for (GLTFSkinIndex skin_i = 0; skin_i < state->skins.size(); ++skin_i) {
-		Ref<GLTFSkin> skin = state->skins.write[skin_i];
-		if (skin->skin_root == node_index) {
-			skin->skin_root = fake_joint_index;
+			Ref<GLTFNode> node = state->nodes[subtree_nodes[subtree_i]];
+			node->joint = true;
+			// Add the joint to the skeletons joints
+			skeleton->joints.push_back(subtree_nodes[subtree_i]);
 		}
 	}
 
@@ -4920,10 +4849,9 @@ void GLTFDocument::_assign_scene_names(Ref<GLTFState> state) {
 	}
 }
 
-BoneAttachment3D *GLTFDocument::_generate_bone_attachment(Ref<GLTFState> state, Skeleton3D *skeleton, const GLTFNodeIndex node_index) {
+BoneAttachment3D *GLTFDocument::_generate_bone_attachment(Ref<GLTFState> state, Skeleton3D *skeleton, const GLTFNodeIndex node_index, const GLTFNodeIndex bone_index) {
 	Ref<GLTFNode> gltf_node = state->nodes[node_index];
-	Ref<GLTFNode> bone_node = state->nodes[gltf_node->parent];
-
+	Ref<GLTFNode> bone_node = state->nodes[bone_index];
 	BoneAttachment3D *bone_attachment = memnew(BoneAttachment3D);
 	print_verbose("glTF: Creating bone attachment for: " + gltf_node->get_name());
 
@@ -5008,7 +4936,7 @@ EditorSceneImporterMeshNode3D *GLTFDocument::_generate_mesh_instance(Ref<GLTFSta
 	return mi;
 }
 
-Light3D *GLTFDocument::_generate_light(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index) {
+Node3D *GLTFDocument::_generate_light(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index) {
 	Ref<GLTFNode> gltf_node = state->nodes[node_index];
 
 	ERR_FAIL_INDEX_V(gltf_node->light, state->lights.size(), nullptr);
@@ -5057,7 +4985,7 @@ Light3D *GLTFDocument::_generate_light(Ref<GLTFState> state, Node *scene_parent,
 		light->set_param(SpotLight3D::PARAM_SPOT_ATTENUATION, angle_attenuation);
 		return light;
 	}
-	return nullptr;
+	return memnew(Node3D);
 }
 
 Camera3D *GLTFDocument::_generate_camera(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index) {
@@ -5429,31 +5357,22 @@ void GLTFDocument::_convert_mesh_to_gltf(Node *p_scene_parent, Ref<GLTFState> st
 void GLTFDocument::_generate_scene_node(Ref<GLTFState> state, Node *scene_parent, Node3D *scene_root, const GLTFNodeIndex node_index) {
 	Ref<GLTFNode> gltf_node = state->nodes[node_index];
 
+	if (gltf_node->skeleton >= 0) {
+		_generate_skeleton_bone_node(state, scene_parent, scene_root, node_index);
+		return;
+	}
+
 	Node3D *current_node = nullptr;
 
 	// Is our parent a skeleton
 	Skeleton3D *active_skeleton = Object::cast_to<Skeleton3D>(scene_parent);
 
-	if (gltf_node->skeleton >= 0) {
-		Skeleton3D *skeleton = state->skeletons[gltf_node->skeleton]->godot_skeleton;
-
-		if (active_skeleton != skeleton) {
-			ERR_FAIL_COND_MSG(active_skeleton != nullptr, "glTF: Generating scene detected direct parented Skeletons");
-
-			// Add it to the scene if it has not already been added
-			if (skeleton->get_parent() == nullptr) {
-				scene_parent->add_child(skeleton);
-				skeleton->set_owner(scene_root);
-			}
-		}
-
-		active_skeleton = skeleton;
-		current_node = skeleton;
-	}
+	const bool non_bone_parented_to_skeleton = active_skeleton;
 
-	// If we have an active skeleton, and the node is node skinned, we need to create a bone attachment
-	if (current_node == nullptr && active_skeleton != nullptr && gltf_node->skin < 0) {
-		BoneAttachment3D *bone_attachment = _generate_bone_attachment(state, active_skeleton, node_index);
+	// skinned meshes must not be placed in a bone attachment.
+	if (non_bone_parented_to_skeleton && gltf_node->skin < 0) {
+		// Bone Attachment - Parent Case
+		BoneAttachment3D *bone_attachment = _generate_bone_attachment(state, active_skeleton, node_index, gltf_node->parent);
 
 		scene_parent->add_child(bone_attachment);
 		bone_attachment->set_owner(scene_root);
@@ -5467,7 +5386,86 @@ void GLTFDocument::_generate_scene_node(Ref<GLTFState> state, Node *scene_parent
 	}
 
 	// We still have not managed to make a node
-	if (current_node == nullptr) {
+	if (gltf_node->mesh >= 0) {
+		current_node = _generate_mesh_instance(state, scene_parent, node_index);
+	} else if (gltf_node->camera >= 0) {
+		current_node = _generate_camera(state, scene_parent, node_index);
+	} else if (gltf_node->light >= 0) {
+		current_node = _generate_light(state, scene_parent, node_index);
+	} else {
+		current_node = _generate_spatial(state, scene_parent, node_index);
+	}
+
+	scene_parent->add_child(current_node);
+	if (current_node != scene_root) {
+		current_node->set_owner(scene_root);
+	}
+	current_node->set_transform(gltf_node->xform);
+	current_node->set_name(gltf_node->get_name());
+
+	state->scene_nodes.insert(node_index, current_node);
+
+	for (int i = 0; i < gltf_node->children.size(); ++i) {
+		_generate_scene_node(state, current_node, scene_root, gltf_node->children[i]);
+	}
+}
+
+void GLTFDocument::_generate_skeleton_bone_node(Ref<GLTFState> state, Node *scene_parent, Node3D *scene_root, const GLTFNodeIndex node_index) {
+	Ref<GLTFNode> gltf_node = state->nodes[node_index];
+
+	Node3D *current_node = nullptr;
+
+	Skeleton3D *skeleton = state->skeletons[gltf_node->skeleton]->godot_skeleton;
+	// In this case, this node is already a bone in skeleton.
+	const bool is_skinned_mesh = (gltf_node->skin >= 0 && gltf_node->mesh >= 0);
+	const bool requires_extra_node = (gltf_node->mesh >= 0 || gltf_node->camera >= 0 || gltf_node->light >= 0);
+
+	Skeleton3D *active_skeleton = Object::cast_to<Skeleton3D>(scene_parent);
+	if (active_skeleton != skeleton) {
+		if (active_skeleton) {
+			// Bone Attachment - Direct Parented Skeleton Case
+			BoneAttachment3D *bone_attachment = _generate_bone_attachment(state, active_skeleton, node_index, gltf_node->parent);
+
+			scene_parent->add_child(bone_attachment);
+			bone_attachment->set_owner(scene_root);
+
+			// There is no gltf_node that represent this, so just directly create a unique name
+			bone_attachment->set_name(_gen_unique_name(state, "BoneAttachment3D"));
+
+			// We change the scene_parent to our bone attachment now. We do not set current_node because we want to make the node
+			// and attach it to the bone_attachment
+			scene_parent = bone_attachment;
+			WARN_PRINT(vformat("glTF: Generating scene detected direct parented Skeletons at node %d", node_index));
+		}
+
+		// Add it to the scene if it has not already been added
+		if (skeleton->get_parent() == nullptr) {
+			scene_parent->add_child(skeleton);
+			skeleton->set_owner(scene_root);
+		}
+	}
+
+	active_skeleton = skeleton;
+	current_node = skeleton;
+
+	if (requires_extra_node) {
+		// skinned meshes must not be placed in a bone attachment.
+		if (!is_skinned_mesh) {
+			// Bone Attachment - Same Node Case
+			BoneAttachment3D *bone_attachment = _generate_bone_attachment(state, active_skeleton, node_index, node_index);
+
+			scene_parent->add_child(bone_attachment);
+			bone_attachment->set_owner(scene_root);
+
+			// There is no gltf_node that represent this, so just directly create a unique name
+			bone_attachment->set_name(_gen_unique_name(state, "BoneAttachment3D"));
+
+			// We change the scene_parent to our bone attachment now. We do not set current_node because we want to make the node
+			// and attach it to the bone_attachment
+			scene_parent = bone_attachment;
+		}
+
+		// We still have not managed to make a node
 		if (gltf_node->mesh >= 0) {
 			current_node = _generate_mesh_instance(state, scene_parent, node_index);
 		} else if (gltf_node->camera >= 0) {
@@ -5476,22 +5474,18 @@ void GLTFDocument::_generate_scene_node(Ref<GLTFState> state, Node *scene_parent
 			current_node = _generate_light(state, scene_parent, node_index);
 		}
 
-		if (!current_node) {
-			current_node = _generate_spatial(state, scene_parent, node_index);
-		}
-
 		scene_parent->add_child(current_node);
 		if (current_node != scene_root) {
 			current_node->set_owner(scene_root);
 		}
-		current_node->set_transform(gltf_node->xform);
+		// Do not set transform here. Transform is already applied to our bone.
 		current_node->set_name(gltf_node->get_name());
 	}
 
 	state->scene_nodes.insert(node_index, current_node);
 
 	for (int i = 0; i < gltf_node->children.size(); ++i) {
-		_generate_scene_node(state, current_node, scene_root, gltf_node->children[i]);
+		_generate_scene_node(state, active_skeleton, scene_root, gltf_node->children[i]);
 	}
 }
 
@@ -5632,28 +5626,30 @@ void GLTFDocument::_import_animation(Ref<GLTFState> state, AnimationPlayer *ap,
 
 	for (Map<int, GLTFAnimation::Track>::Element *track_i = anim->get_tracks().front(); track_i; track_i = track_i->next()) {
 		const GLTFAnimation::Track &track = track_i->get();
-		//need to find the path
+		//need to find the path: for skeletons, weight tracks will affect the mesh
 		NodePath node_path;
+		//for skeletons, transform tracks always affect bones
+		NodePath transform_node_path;
 
 		GLTFNodeIndex node_index = track_i->key();
-		if (state->nodes[node_index]->fake_joint_parent >= 0) {
-			// Should be same as parent
-			node_index = state->nodes[node_index]->fake_joint_parent;
-		}
 
 		const Ref<GLTFNode> gltf_node = state->nodes[track_i->key()];
 
+		Node *root = ap->get_parent();
+		ERR_FAIL_COND(root == nullptr);
+		Map<GLTFNodeIndex, Node *>::Element *node_element = state->scene_nodes.find(node_index);
+		ERR_CONTINUE_MSG(node_element == nullptr, vformat("Unable to find node %d for animation", node_index));
+		node_path = root->get_path_to(node_element->get());
+
 		if (gltf_node->skeleton >= 0) {
-			const Skeleton3D *sk = Object::cast_to<Skeleton3D>(state->scene_nodes.find(node_index)->get());
+			const Skeleton3D *sk = state->skeletons[gltf_node->skeleton]->godot_skeleton;
 			ERR_FAIL_COND(sk == nullptr);
 
 			const String path = ap->get_parent()->get_path_to(sk);
 			const String bone = gltf_node->get_name();
-			node_path = path + ":" + bone;
+			transform_node_path = path + ":" + bone;
 		} else {
-			Node *root = ap->get_parent();
-			Node *godot_node = state->scene_nodes.find(node_index)->get();
-			node_path = root->get_path_to(godot_node);
+			transform_node_path = node_path;
 		}
 
 		for (int i = 0; i < track.rotation_track.times.size(); i++) {
@@ -5672,11 +5668,13 @@ void GLTFDocument::_import_animation(Ref<GLTFState> state, AnimationPlayer *ap,
 			}
 		}
 
-		if (track.rotation_track.values.size() || track.translation_track.values.size() || track.scale_track.values.size()) {
+		// Animated TRS properties will not affect a skinned mesh.
+		const bool transform_affects_skinned_mesh_instance = gltf_node->skeleton < 0 && gltf_node->skin >= 0;
+		if ((track.rotation_track.values.size() || track.translation_track.values.size() || track.scale_track.values.size()) && !transform_affects_skinned_mesh_instance) {
 			//make transform track
 			int track_idx = animation->get_track_count();
 			animation->add_track(Animation::TYPE_TRANSFORM);
-			animation->track_set_path(track_idx, node_path);
+			animation->track_set_path(track_idx, transform_node_path);
 			//first determine animation length
 
 			const double increment = 1.0 / bake_fps;
diff --git a/modules/gltf/gltf_document.h b/modules/gltf/gltf_document.h
index bda1ce87d6..900c367010 100644
--- a/modules/gltf/gltf_document.h
+++ b/modules/gltf/gltf_document.h
@@ -260,11 +260,12 @@ private:
 	Error _serialize_animations(Ref<GLTFState> state);
 	BoneAttachment3D *_generate_bone_attachment(Ref<GLTFState> state,
 			Skeleton3D *skeleton,
-			const GLTFNodeIndex node_index);
+			const GLTFNodeIndex node_index,
+			const GLTFNodeIndex bone_index);
 	EditorSceneImporterMeshNode3D *_generate_mesh_instance(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index);
 	Camera3D *_generate_camera(Ref<GLTFState> state, Node *scene_parent,
 			const GLTFNodeIndex node_index);
-	Light3D *_generate_light(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index);
+	Node3D *_generate_light(Ref<GLTFState> state, Node *scene_parent, const GLTFNodeIndex node_index);
 	Node3D *_generate_spatial(Ref<GLTFState> state, Node *scene_parent,
 			const GLTFNodeIndex node_index);
 	void _assign_scene_names(Ref<GLTFState> state);
@@ -365,6 +366,7 @@ public:
 	void _generate_scene_node(Ref<GLTFState> state, Node *scene_parent,
 			Node3D *scene_root,
 			const GLTFNodeIndex node_index);
+	void _generate_skeleton_bone_node(Ref<GLTFState> state, Node *scene_parent, Node3D *scene_root, const GLTFNodeIndex node_index);
 	void _import_animation(Ref<GLTFState> state, AnimationPlayer *ap,
 			const GLTFAnimationIndex index, const int bake_fps);
 	GLTFMeshIndex _convert_mesh_instance(Ref<GLTFState> state,
diff --git a/modules/gltf/gltf_node.cpp b/modules/gltf/gltf_node.cpp
index 777c6fbd9a..f6f33ef009 100644
--- a/modules/gltf/gltf_node.cpp
+++ b/modules/gltf/gltf_node.cpp
@@ -55,8 +55,6 @@ void GLTFNode::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_scale", "scale"), &GLTFNode::set_scale);
 	ClassDB::bind_method(D_METHOD("get_children"), &GLTFNode::get_children);
 	ClassDB::bind_method(D_METHOD("set_children", "children"), &GLTFNode::set_children);
-	ClassDB::bind_method(D_METHOD("get_fake_joint_parent"), &GLTFNode::get_fake_joint_parent);
-	ClassDB::bind_method(D_METHOD("set_fake_joint_parent", "fake_joint_parent"), &GLTFNode::set_fake_joint_parent);
 	ClassDB::bind_method(D_METHOD("get_light"), &GLTFNode::get_light);
 	ClassDB::bind_method(D_METHOD("set_light", "light"), &GLTFNode::set_light);
 
@@ -72,7 +70,6 @@ void GLTFNode::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::QUAT, "rotation"), "set_rotation", "get_rotation"); // Quat
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "scale"), "set_scale", "get_scale"); // Vector3
 	ADD_PROPERTY(PropertyInfo(Variant::PACKED_INT32_ARRAY, "children"), "set_children", "get_children"); // Vector<int>
-	ADD_PROPERTY(PropertyInfo(Variant::INT, "fake_joint_parent"), "set_fake_joint_parent", "get_fake_joint_parent"); // GLTFNodeIndex
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "light"), "set_light", "get_light"); // GLTFLightIndex
 }
 
@@ -172,14 +169,6 @@ void GLTFNode::set_children(Vector<int> p_children) {
 	children = p_children;
 }
 
-GLTFNodeIndex GLTFNode::get_fake_joint_parent() {
-	return fake_joint_parent;
-}
-
-void GLTFNode::set_fake_joint_parent(GLTFNodeIndex p_fake_joint_parent) {
-	fake_joint_parent = p_fake_joint_parent;
-}
-
 GLTFLightIndex GLTFNode::get_light() {
 	return light;
 }
diff --git a/modules/gltf/gltf_node.h b/modules/gltf/gltf_node.h
index ce8aff8944..3a5689d004 100644
--- a/modules/gltf/gltf_node.h
+++ b/modules/gltf/gltf_node.h
@@ -53,7 +53,6 @@ private:
 	Quat rotation;
 	Vector3 scale = Vector3(1, 1, 1);
 	Vector<int> children;
-	GLTFNodeIndex fake_joint_parent = -1;
 	GLTFLightIndex light = -1;
 
 protected:
@@ -96,9 +95,6 @@ public:
 	Vector<int> get_children();
 	void set_children(Vector<int> p_children);
 
-	GLTFNodeIndex get_fake_joint_parent();
-	void set_fake_joint_parent(GLTFNodeIndex p_fake_joint_parent);
-
 	GLTFLightIndex get_light();
 	void set_light(GLTFLightIndex p_light);
 };