6 files changed, 64 insertions, 0 deletions
diff --git a/modules/gltf/doc_classes/GLTFNode.xml b/modules/gltf/doc_classes/GLTFNode.xml
index 4d1aa89ac9..8e48066623 100644
--- a/modules/gltf/doc_classes/GLTFNode.xml
+++ b/modules/gltf/doc_classes/GLTFNode.xml
@@ -9,6 +9,25 @@
 	<tutorials>
 		<link title="GLTF scene and node spec">https://github.com/KhronosGroup/glTF-Tutorials/blob/master/gltfTutorial/gltfTutorial_004_ScenesNodes.md"</link>
 	</tutorials>
+	<methods>
+		<method name="get_additional_data">
+			<return type="Variant" />
+			<param index="0" name="extension_name" type="StringName" />
+			<description>
+				Gets additional arbitrary data in this [GLTFNode] instance. This can be used to keep per-node state data in [GLTFDocumentExtension] classes, which is important because they are stateless.
+				The argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the return value can be anything you set. If nothing was set, the return value is null.
+			</description>
+		</method>
+		<method name="set_additional_data">
+			<return type="void" />
+			<param index="0" name="extension_name" type="StringName" />
+			<param index="1" name="additional_data" type="Variant" />
+			<description>
+				Sets additional arbitrary data in this [GLTFNode] instance. This can be used to keep per-node state data in [GLTFDocumentExtension] classes, which is important because they are stateless.
+				The first argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the second argument can be anything you want.
+			</description>
+		</method>
+	</methods>
 	<members>
 		<member name="camera" type="int" setter="set_camera" getter="get_camera" default="-1">
 		</member>
diff --git a/modules/gltf/doc_classes/GLTFState.xml b/modules/gltf/doc_classes/GLTFState.xml
index 56f3a70631..d0740cf7ca 100644
--- a/modules/gltf/doc_classes/GLTFState.xml
+++ b/modules/gltf/doc_classes/GLTFState.xml
@@ -20,6 +20,14 @@
 			<description>
 			</description>
 		</method>
+		<method name="get_additional_data">
+			<return type="Variant" />
+			<param index="0" name="extension_name" type="StringName" />
+			<description>
+				Gets additional arbitrary data in this [GLTFState] instance. This can be used to keep per-file state data in [GLTFDocumentExtension] classes, which is important because they are stateless.
+				The argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the return value can be anything you set. If nothing was set, the return value is null.
+			</description>
+		</method>
 		<method name="get_animation_player">
 			<return type="AnimationPlayer" />
 			<param index="0" name="idx" type="int" />
@@ -120,6 +128,15 @@
 			<description>
 			</description>
 		</method>
+		<method name="set_additional_data">
+			<return type="void" />
+			<param index="0" name="extension_name" type="StringName" />
+			<param index="1" name="additional_data" type="Variant" />
+			<description>
+				Sets additional arbitrary data in this [GLTFState] instance. This can be used to keep per-file state data in [GLTFDocumentExtension] classes, which is important because they are stateless.
+				The first argument should be the [GLTFDocumentExtension] name (does not have to match the extension name in the GLTF file), and the second argument can be anything you want.
+			</description>
+		</method>
 		<method name="set_animations">
 			<return type="void" />
 			<param index="0" name="animations" type="GLTFAnimation[]" />
diff --git a/modules/gltf/gltf_state.cpp b/modules/gltf/gltf_state.cpp
index 60192c67e6..ac5665e396 100644
--- a/modules/gltf/gltf_state.cpp
+++ b/modules/gltf/gltf_state.cpp
@@ -87,6 +87,8 @@ void GLTFState::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_animations"), &GLTFState::get_animations);
 	ClassDB::bind_method(D_METHOD("set_animations", "animations"), &GLTFState::set_animations);
 	ClassDB::bind_method(D_METHOD("get_scene_node", "idx"), &GLTFState::get_scene_node);
+	ClassDB::bind_method(D_METHOD("get_additional_data", "extension_name"), &GLTFState::get_additional_data);
+	ClassDB::bind_method(D_METHOD("set_additional_data", "extension_name", "additional_data"), &GLTFState::set_additional_data);
 
 	ADD_PROPERTY(PropertyInfo(Variant::DICTIONARY, "json"), "set_json", "get_json"); // Dictionary
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "major_version"), "set_major_version", "get_major_version"); // int
@@ -358,3 +360,11 @@ String GLTFState::get_base_path() {
 void GLTFState::set_base_path(String p_base_path) {
 	base_path = p_base_path;
 }
+
+Variant GLTFState::get_additional_data(const StringName &p_extension_name) {
+	return additional_data[p_extension_name];
+}
+
+void GLTFState::set_additional_data(const StringName &p_extension_name, Variant p_additional_data) {
+	additional_data[p_extension_name] = p_additional_data;
+}
diff --git a/modules/gltf/gltf_state.h b/modules/gltf/gltf_state.h
index afe7e82010..e24017b0fd 100644
--- a/modules/gltf/gltf_state.h
+++ b/modules/gltf/gltf_state.h
@@ -97,6 +97,7 @@ class GLTFState : public Resource {
 
 	HashMap<ObjectID, GLTFSkeletonIndex> skeleton3d_to_gltf_skeleton;
 	HashMap<ObjectID, HashMap<ObjectID, GLTFSkinIndex>> skin_and_skeleton3d_to_gltf_skin;
+	Dictionary additional_data;
 
 protected:
 	static void _bind_methods();
@@ -191,6 +192,9 @@ public:
 
 	AnimationPlayer *get_animation_player(int idx);
 
+	Variant get_additional_data(const StringName &p_extension_name);
+	void set_additional_data(const StringName &p_extension_name, Variant p_additional_data);
+
 	//void set_scene_nodes(RBMap<GLTFNodeIndex, Node *> p_scene_nodes) {
 	//	this->scene_nodes = p_scene_nodes;
 	//}
diff --git a/modules/gltf/structures/gltf_node.cpp b/modules/gltf/structures/gltf_node.cpp
index 86280603fa..6fd36f93b7 100644
--- a/modules/gltf/structures/gltf_node.cpp
+++ b/modules/gltf/structures/gltf_node.cpp
@@ -57,6 +57,8 @@ void GLTFNode::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_children", "children"), &GLTFNode::set_children);
 	ClassDB::bind_method(D_METHOD("get_light"), &GLTFNode::get_light);
 	ClassDB::bind_method(D_METHOD("set_light", "light"), &GLTFNode::set_light);
+	ClassDB::bind_method(D_METHOD("get_additional_data", "extension_name"), &GLTFNode::get_additional_data);
+	ClassDB::bind_method(D_METHOD("set_additional_data", "extension_name", "additional_data"), &GLTFNode::set_additional_data);
 
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "parent"), "set_parent", "get_parent"); // GLTFNodeIndex
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "height"), "set_height", "get_height"); // int
@@ -176,3 +178,11 @@ GLTFLightIndex GLTFNode::get_light() {
 void GLTFNode::set_light(GLTFLightIndex p_light) {
 	light = p_light;
 }
+
+Variant GLTFNode::get_additional_data(const StringName &p_extension_name) {
+	return additional_data[p_extension_name];
+}
+
+void GLTFNode::set_additional_data(const StringName &p_extension_name, Variant p_additional_data) {
+	additional_data[p_extension_name] = p_additional_data;
+}
diff --git a/modules/gltf/structures/gltf_node.h b/modules/gltf/structures/gltf_node.h
index 1a57ea32e2..90a4fa99ed 100644
--- a/modules/gltf/structures/gltf_node.h
+++ b/modules/gltf/structures/gltf_node.h
@@ -53,6 +53,7 @@ private:
 	Vector3 scale = Vector3(1, 1, 1);
 	Vector<int> children;
 	GLTFLightIndex light = -1;
+	Dictionary additional_data;
 
 protected:
 	static void _bind_methods();
@@ -96,6 +97,9 @@ public:
 
 	GLTFLightIndex get_light();
 	void set_light(GLTFLightIndex p_light);
+
+	Variant get_additional_data(const StringName &p_extension_name);
+	void set_additional_data(const StringName &p_extension_name, Variant p_additional_data);
 };
 
 #endif // GLTF_NODE_H