Merge pull request #88798 from Malcolmnixon/xr-body-tracker

XR: Add body tracking support.

doc/classes/XRBodyModifier3D.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="XRBodyModifier3D" inherits="Node3D" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
+	<brief_description>
+		A node for driving body meshes from [XRBodyTracker] data.
+	</brief_description>
+	<description>
+		This node uses body tracking data from a [XRBodyTracker] to animate the skeleton of a body mesh.
+	</description>
+	<tutorials>
+		<link title="XR documentation index">$DOCS_URL/tutorials/xr/index.html</link>
+	</tutorials>
+	<members>
+		<member name="body_tracker" type="StringName" setter="set_body_tracker" getter="get_body_tracker" default="&amp;&quot;/user/body&quot;">
+			The name of the [XRBodyTracker] registered with [XRServer] to obtain the body tracking data from.
+		</member>
+		<member name="body_update" type="int" setter="set_body_update" getter="get_body_update" enum="XRBodyModifier3D.BodyUpdate" is_bitfield="true" default="7">
+			Specifies the body parts to update.
+		</member>
+		<member name="bone_update" type="int" setter="set_bone_update" getter="get_bone_update" enum="XRBodyModifier3D.BoneUpdate" default="0">
+			Specifies the type of updates to perform on the bones.
+		</member>
+		<member name="show_when_tracked" type="bool" setter="set_show_when_tracked" getter="get_show_when_tracked" default="true">
+			If true then the nodes visibility is determined by whether tracking data is available.
+		</member>
+		<member name="target" type="NodePath" setter="set_target" getter="get_target" default="NodePath(&quot;&quot;)">
+			A [NodePath] to a [Skeleton3D] to animate.
+		</member>
+	</members>
+	<constants>
+		<constant name="BODY_UPDATE_UPPER_BODY" value="1" enum="BodyUpdate" is_bitfield="true">
+			The skeleton's upper body joints are updated.
+		</constant>
+		<constant name="BODY_UPDATE_LOWER_BODY" value="2" enum="BodyUpdate" is_bitfield="true">
+			The skeleton's lower body joints are updated.
+		</constant>
+		<constant name="BODY_UPDATE_HANDS" value="4" enum="BodyUpdate" is_bitfield="true">
+			The skeleton's hand joints are updated.
+		</constant>
+		<constant name="BONE_UPDATE_FULL" value="0" enum="BoneUpdate">
+			The skeleton's bones are fully updated (both position and rotation) to match the tracked bones.
+		</constant>
+		<constant name="BONE_UPDATE_ROTATION_ONLY" value="1" enum="BoneUpdate">
+			The skeleton's bones are only rotated to align with the tracked bones, preserving bone length.
+		</constant>
+		<constant name="BONE_UPDATE_MAX" value="2" enum="BoneUpdate">
+			Represents the size of the [enum BoneUpdate] enum.
+		</constant>
+	</constants>
+</class>

doc/classes/XRBodyTracker.xml

@@ -0,0 +1,307 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="XRBodyTracker" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
+	<brief_description>
+		A tracked body in XR.
+	</brief_description>
+	<description>
+		A body tracking system will create an instance of this object and add it to the [XRServer]. This tracking system will then obtain skeleton data, convert it to the Godot Humanoid skeleton and store this data on the [XRBodyTracker] object.
+		Use [XRBodyModifier3D] to animate a body mesh using body tracking data.
+	</description>
+	<tutorials>
+		<link title="XR documentation index">$DOCS_URL/tutorials/xr/index.html</link>
+	</tutorials>
+	<methods>
+		<method name="get_joint_flags" qualifiers="const">
+			<return type="int" enum="XRBodyTracker.JointFlags" is_bitfield="true" />
+			<param index="0" name="joint" type="int" enum="XRBodyTracker.Joint" />
+			<description>
+				Returns flags about the validity of the tracking data for the given body joint (see [enum XRBodyTracker.JointFlags]).
+			</description>
+		</method>
+		<method name="get_joint_transform" qualifiers="const">
+			<return type="Transform3D" />
+			<param index="0" name="joint" type="int" enum="XRBodyTracker.Joint" />
+			<description>
+				Returns the transform for the given body joint.
+			</description>
+		</method>
+		<method name="set_joint_flags">
+			<return type="void" />
+			<param index="0" name="joint" type="int" enum="XRBodyTracker.Joint" />
+			<param index="1" name="flags" type="int" enum="XRBodyTracker.JointFlags" is_bitfield="true" />
+			<description>
+				Sets flags about the validity of the tracking data for the given body joint.
+			</description>
+		</method>
+		<method name="set_joint_transform">
+			<return type="void" />
+			<param index="0" name="joint" type="int" enum="XRBodyTracker.Joint" />
+			<param index="1" name="transform" type="Transform3D" />
+			<description>
+				Sets the transform for the given body joint.
+			</description>
+		</method>
+	</methods>
+	<members>
+		<member name="body_flags" type="int" setter="set_body_flags" getter="get_body_flags" enum="XRBodyTracker.BodyFlags" is_bitfield="true" default="0">
+			The type of body tracking data captured.
+		</member>
+		<member name="has_tracking_data" type="bool" setter="set_has_tracking_data" getter="get_has_tracking_data" default="false">
+			If [code]true[/code], the body tracking data is valid.
+		</member>
+	</members>
+	<constants>
+		<constant name="BODY_FLAG_UPPER_BODY_SUPPORTED" value="1" enum="BodyFlags" is_bitfield="true">
+			Upper body tracking supported.
+		</constant>
+		<constant name="BODY_FLAG_LOWER_BODY_SUPPORTED" value="2" enum="BodyFlags" is_bitfield="true">
+			Lower body tracking supported.
+		</constant>
+		<constant name="BODY_FLAG_HANDS_SUPPORTED" value="4" enum="BodyFlags" is_bitfield="true">
+			Hand tracking supported.
+		</constant>
+		<constant name="JOINT_ROOT" value="0" enum="Joint">
+			Root joint.
+		</constant>
+		<constant name="JOINT_HIPS" value="1" enum="Joint">
+			Hips joint.
+		</constant>
+		<constant name="JOINT_SPINE" value="2" enum="Joint">
+			Spine joint.
+		</constant>
+		<constant name="JOINT_CHEST" value="3" enum="Joint">
+			Chest joint.
+		</constant>
+		<constant name="JOINT_UPPER_CHEST" value="4" enum="Joint">
+			Upper chest joint.
+		</constant>
+		<constant name="JOINT_NECK" value="5" enum="Joint">
+			Neck joint.
+		</constant>
+		<constant name="JOINT_HEAD" value="6" enum="Joint">
+			Head joint.
+		</constant>
+		<constant name="JOINT_HEAD_TIP" value="7" enum="Joint">
+			Head tip joint.
+		</constant>
+		<constant name="JOINT_LEFT_SHOULDER" value="8" enum="Joint">
+			Left shoulder joint.
+		</constant>
+		<constant name="JOINT_LEFT_UPPER_ARM" value="9" enum="Joint">
+			Left upper arm joint.
+		</constant>
+		<constant name="JOINT_LEFT_LOWER_ARM" value="10" enum="Joint">
+			Left lower arm joint.
+		</constant>
+		<constant name="JOINT_RIGHT_SHOULDER" value="11" enum="Joint">
+			Right shoulder joint.
+		</constant>
+		<constant name="JOINT_RIGHT_UPPER_ARM" value="12" enum="Joint">
+			Right upper arm joint.
+		</constant>
+		<constant name="JOINT_RIGHT_LOWER_ARM" value="13" enum="Joint">
+			Right lower arm joint.
+		</constant>
+		<constant name="JOINT_LEFT_UPPER_LEG" value="14" enum="Joint">
+			Left upper leg joint.
+		</constant>
+		<constant name="JOINT_LEFT_LOWER_LEG" value="15" enum="Joint">
+			Left lower leg joint.
+		</constant>
+		<constant name="JOINT_LEFT_FOOT" value="16" enum="Joint">
+			Left foot joint.
+		</constant>
+		<constant name="JOINT_LEFT_TOES" value="17" enum="Joint">
+			Left toes joint.
+		</constant>
+		<constant name="JOINT_RIGHT_UPPER_LEG" value="18" enum="Joint">
+			Right upper leg joint.
+		</constant>
+		<constant name="JOINT_RIGHT_LOWER_LEG" value="19" enum="Joint">
+			Right lower leg joint.
+		</constant>
+		<constant name="JOINT_RIGHT_FOOT" value="20" enum="Joint">
+			Right foot joint.
+		</constant>
+		<constant name="JOINT_RIGHT_TOES" value="21" enum="Joint">
+			Right toes joint.
+		</constant>
+		<constant name="JOINT_LEFT_HAND" value="22" enum="Joint">
+			Left hand joint.
+		</constant>
+		<constant name="JOINT_LEFT_PALM" value="23" enum="Joint">
+			Left palm joint.
+		</constant>
+		<constant name="JOINT_LEFT_WRIST" value="24" enum="Joint">
+			Left wrist joint.
+		</constant>
+		<constant name="JOINT_LEFT_THUMB_METACARPAL" value="25" enum="Joint">
+			Left thumb metacarpal joint.
+		</constant>
+		<constant name="JOINT_LEFT_THUMB_PHALANX_PROXIMAL" value="26" enum="Joint">
+			Left thumb phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_LEFT_THUMB_PHALANX_DISTAL" value="27" enum="Joint">
+			Left thumb phalanx distal joint.
+		</constant>
+		<constant name="JOINT_LEFT_THUMB_TIP" value="28" enum="Joint">
+			Left thumb tip joint.
+		</constant>
+		<constant name="JOINT_LEFT_INDEX_FINGER_METACARPAL" value="29" enum="Joint">
+			Left index finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_LEFT_INDEX_FINGER_PHALANX_PROXIMAL" value="30" enum="Joint">
+			Left index finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_LEFT_INDEX_FINGER_PHALANX_INTERMEDIATE" value="31" enum="Joint">
+			Left index finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_LEFT_INDEX_FINGER_PHALANX_DISTAL" value="32" enum="Joint">
+			Left index finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_LEFT_INDEX_FINGER_TIP" value="33" enum="Joint">
+			Left index finger tip joint.
+		</constant>
+		<constant name="JOINT_LEFT_MIDDLE_FINGER_METACARPAL" value="34" enum="Joint">
+			Left middle finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_LEFT_MIDDLE_FINGER_PHALANX_PROXIMAL" value="35" enum="Joint">
+			Left middle finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_LEFT_MIDDLE_FINGER_PHALANX_INTERMEDIATE" value="36" enum="Joint">
+			Left middle finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_LEFT_MIDDLE_FINGER_PHALANX_DISTAL" value="37" enum="Joint">
+			Left middle finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_LEFT_MIDDLE_FINGER_TIP" value="38" enum="Joint">
+			Left middle finger tip joint.
+		</constant>
+		<constant name="JOINT_LEFT_RING_FINGER_METACARPAL" value="39" enum="Joint">
+			Left ring finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_LEFT_RING_FINGER_PHALANX_PROXIMAL" value="40" enum="Joint">
+			Left ring finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_LEFT_RING_FINGER_PHALANX_INTERMEDIATE" value="41" enum="Joint">
+			Left ring finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_LEFT_RING_FINGER_PHALANX_DISTAL" value="42" enum="Joint">
+			Left ring finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_LEFT_RING_FINGER_TIP" value="43" enum="Joint">
+			Left ring finger tip joint.
+		</constant>
+		<constant name="JOINT_LEFT_PINKY_FINGER_METACARPAL" value="44" enum="Joint">
+			Left pinky finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_LEFT_PINKY_FINGER_PHALANX_PROXIMAL" value="45" enum="Joint">
+			Left pinky finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_LEFT_PINKY_FINGER_PHALANX_INTERMEDIATE" value="46" enum="Joint">
+			Left pinky finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_LEFT_PINKY_FINGER_PHALANX_DISTAL" value="47" enum="Joint">
+			Left pinky finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_LEFT_PINKY_FINGER_TIP" value="48" enum="Joint">
+			Left pinky finger tip joint.
+		</constant>
+		<constant name="JOINT_RIGHT_HAND" value="49" enum="Joint">
+			Right hand joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PALM" value="50" enum="Joint">
+			Right palm joint.
+		</constant>
+		<constant name="JOINT_RIGHT_WRIST" value="51" enum="Joint">
+			Right wrist joint.
+		</constant>
+		<constant name="JOINT_RIGHT_THUMB_METACARPAL" value="52" enum="Joint">
+			Right thumb metacarpal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_THUMB_PHALANX_PROXIMAL" value="53" enum="Joint">
+			Right thumb phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_THUMB_PHALANX_DISTAL" value="54" enum="Joint">
+			Right thumb phalanx distal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_THUMB_TIP" value="55" enum="Joint">
+			Right thumb tip joint.
+		</constant>
+		<constant name="JOINT_RIGHT_INDEX_FINGER_METACARPAL" value="56" enum="Joint">
+			Right index finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_INDEX_FINGER_PHALANX_PROXIMAL" value="57" enum="Joint">
+			Right index finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_INDEX_FINGER_PHALANX_INTERMEDIATE" value="58" enum="Joint">
+			Right index finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_RIGHT_INDEX_FINGER_PHALANX_DISTAL" value="59" enum="Joint">
+			Right index finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_INDEX_FINGER_TIP" value="60" enum="Joint">
+			Right index finger tip joint.
+		</constant>
+		<constant name="JOINT_RIGHT_MIDDLE_FINGER_METACARPAL" value="61" enum="Joint">
+			Right middle finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_MIDDLE_FINGER_PHALANX_PROXIMAL" value="62" enum="Joint">
+			Right middle finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_MIDDLE_FINGER_PHALANX_INTERMEDIATE" value="63" enum="Joint">
+			Right middle finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_RIGHT_MIDDLE_FINGER_PHALANX_DISTAL" value="64" enum="Joint">
+			Right middle finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_MIDDLE_FINGER_TIP" value="65" enum="Joint">
+			Right middle finger tip joint.
+		</constant>
+		<constant name="JOINT_RIGHT_RING_FINGER_METACARPAL" value="66" enum="Joint">
+			Right ring finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_RING_FINGER_PHALANX_PROXIMAL" value="67" enum="Joint">
+			Right ring finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_RING_FINGER_PHALANX_INTERMEDIATE" value="68" enum="Joint">
+			Right ring finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_RIGHT_RING_FINGER_PHALANX_DISTAL" value="69" enum="Joint">
+			Right ring finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_RING_FINGER_TIP" value="70" enum="Joint">
+			Right ring finger tip joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PINKY_FINGER_METACARPAL" value="71" enum="Joint">
+			Right pinky finger metacarpal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PINKY_FINGER_PHALANX_PROXIMAL" value="72" enum="Joint">
+			Right pinky finger phalanx proximal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PINKY_FINGER_PHALANX_INTERMEDIATE" value="73" enum="Joint">
+			Right pinky finger phalanx intermediate joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PINKY_FINGER_PHALANX_DISTAL" value="74" enum="Joint">
+			Right pinky finger phalanx distal joint.
+		</constant>
+		<constant name="JOINT_RIGHT_PINKY_FINGER_TIP" value="75" enum="Joint">
+			Right pinky finger tip joint.
+		</constant>
+		<constant name="JOINT_MAX" value="76" enum="Joint">
+			Represents the size of the [enum Joint] enum.
+		</constant>
+		<constant name="JOINT_FLAG_ORIENTATION_VALID" value="1" enum="JointFlags" is_bitfield="true">
+			The joint's orientation data is valid.
+		</constant>
+		<constant name="JOINT_FLAG_ORIENTATION_TRACKED" value="2" enum="JointFlags" is_bitfield="true">
+			The joint's orientation is actively tracked. May not be set if tracking has been temporarily lost.
+		</constant>
+		<constant name="JOINT_FLAG_POSITION_VALID" value="4" enum="JointFlags" is_bitfield="true">
+			The joint's position data is valid.
+		</constant>
+		<constant name="JOINT_FLAG_POSITION_TRACKED" value="8" enum="JointFlags" is_bitfield="true">
+			The joint's position is actively tracked. May not be set if tracking has been temporarily lost.
+		</constant>
+	</constants>
+</class>

doc/classes/XRServer.xml

@@ -10,6 +10,14 @@
 		<link title="XR documentation index">$DOCS_URL/tutorials/xr/index.html</link>
 	</tutorials>
 	<methods>
+		<method name="add_body_tracker">
+			<return type="void" />
+			<param index="0" name="tracker_name" type="StringName" />
+			<param index="1" name="body_tracker" type="XRBodyTracker" />
+			<description>
+				Registers a new [XRBodyTracker] that tracks the joints of a body.
+			</description>
+		</method>
 		<method name="add_face_tracker">
 			<return type="void" />
 			<param index="0" name="tracker_name" type="StringName" />
@@ -66,6 +74,19 @@
 				Finds an interface by its [param name]. For example, if your project uses capabilities of an AR/VR platform, you can find the interface for that platform by name and initialize it.
 			</description>
 		</method>
+		<method name="get_body_tracker" qualifiers="const">
+			<return type="XRBodyTracker" />
+			<param index="0" name="tracker_name" type="StringName" />
+			<description>
+				Returns the [XRBodyTracker] with the given tracker name.
+			</description>
+		</method>
+		<method name="get_body_trackers" qualifiers="const">
+			<return type="Dictionary" />
+			<description>
+				Returns a dictionary of the registered body trackers. Each element of the dictionary is a tracker name mapping to the [XRBodyTracker] instance.
+			</description>
+		</method>
 		<method name="get_face_tracker" qualifiers="const">
 			<return type="XRFaceTracker" />
 			<param index="0" name="tracker_name" type="StringName" />
@@ -137,6 +158,13 @@
 				Returns a dictionary of trackers for [param tracker_types].
 			</description>
 		</method>
+		<method name="remove_body_tracker">
+			<return type="void" />
+			<param index="0" name="tracker_name" type="StringName" />
+			<description>
+				Removes a registered [XRBodyTracker].
+			</description>
+		</method>
 		<method name="remove_face_tracker">
 			<return type="void" />
 			<param index="0" name="tracker_name" type="StringName" />
@@ -179,6 +207,26 @@
 		</member>
 	</members>
 	<signals>
+		<signal name="body_tracker_added">
+			<param index="0" name="tracker_name" type="StringName" />
+			<param index="1" name="body_tracker" type="XRBodyTracker" />
+			<description>
+				Emitted when a new body tracker is added.
+			</description>
+		</signal>
+		<signal name="body_tracker_removed">
+			<param index="0" name="tracker_name" type="StringName" />
+			<description>
+				Emitted when a body tracker is removed.
+			</description>
+		</signal>
+		<signal name="body_tracker_updated">
+			<param index="0" name="tracker_name" type="StringName" />
+			<param index="1" name="body_tracker" type="XRBodyTracker" />
+			<description>
+				Emitted when an existing body tracker is updated.
+			</description>
+		</signal>
 		<signal name="face_tracker_added">
 			<param index="0" name="tracker_name" type="StringName" />
 			<param index="1" name="face_tracker" type="XRFaceTracker" />

scene/3d/xr_body_modifier_3d.cpp

@@ -0,0 +1,415 @@
+/**************************************************************************/
+/*  xr_body_modifier_3d.cpp                                               */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "xr_body_modifier_3d.h"
+
+#include "scene/3d/skeleton_3d.h"
+#include "servers/xr/xr_pose.h"
+#include "servers/xr_server.h"
+
+void XRBodyModifier3D::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_body_tracker", "tracker_name"), &XRBodyModifier3D::set_body_tracker);
+	ClassDB::bind_method(D_METHOD("get_body_tracker"), &XRBodyModifier3D::get_body_tracker);
+
+	ClassDB::bind_method(D_METHOD("set_target", "target"), &XRBodyModifier3D::set_target);
+	ClassDB::bind_method(D_METHOD("get_target"), &XRBodyModifier3D::get_target);
+
+	ClassDB::bind_method(D_METHOD("set_body_update", "body_update"), &XRBodyModifier3D::set_body_update);
+	ClassDB::bind_method(D_METHOD("get_body_update"), &XRBodyModifier3D::get_body_update);
+
+	ClassDB::bind_method(D_METHOD("set_bone_update", "bone_update"), &XRBodyModifier3D::set_bone_update);
+	ClassDB::bind_method(D_METHOD("get_bone_update"), &XRBodyModifier3D::get_bone_update);
+
+	ClassDB::bind_method(D_METHOD("set_show_when_tracked", "show"), &XRBodyModifier3D::set_show_when_tracked);
+	ClassDB::bind_method(D_METHOD("get_show_when_tracked"), &XRBodyModifier3D::get_show_when_tracked);
+
+	ADD_PROPERTY(PropertyInfo(Variant::STRING, "body_tracker", PROPERTY_HINT_ENUM_SUGGESTION, "/user/body"), "set_body_tracker", "get_body_tracker");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "target", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Skeleton3D"), "set_target", "get_target");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "body_update", PROPERTY_HINT_FLAGS, "Upper Body,Lower Body,Hands"), "set_body_update", "get_body_update");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "bone_update", PROPERTY_HINT_ENUM, "Full,Rotation Only"), "set_bone_update", "get_bone_update");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "show_when_tracked"), "set_show_when_tracked", "get_show_when_tracked");
+
+	BIND_BITFIELD_FLAG(BODY_UPDATE_UPPER_BODY);
+	BIND_BITFIELD_FLAG(BODY_UPDATE_LOWER_BODY);
+	BIND_BITFIELD_FLAG(BODY_UPDATE_HANDS);
+
+	BIND_ENUM_CONSTANT(BONE_UPDATE_FULL);
+	BIND_ENUM_CONSTANT(BONE_UPDATE_ROTATION_ONLY);
+	BIND_ENUM_CONSTANT(BONE_UPDATE_MAX);
+}
+
+void XRBodyModifier3D::set_body_tracker(const StringName &p_tracker_name) {
+	tracker_name = p_tracker_name;
+}
+
+StringName XRBodyModifier3D::get_body_tracker() const {
+	return tracker_name;
+}
+
+void XRBodyModifier3D::set_target(const NodePath &p_target) {
+	target = p_target;
+
+	if (is_inside_tree()) {
+		_get_joint_data();
+	}
+}
+
+NodePath XRBodyModifier3D::get_target() const {
+	return target;
+}
+
+void XRBodyModifier3D::set_body_update(BitField<BodyUpdate> p_body_update) {
+	body_update = p_body_update;
+}
+
+BitField<XRBodyModifier3D::BodyUpdate> XRBodyModifier3D::get_body_update() const {
+	return body_update;
+}
+
+void XRBodyModifier3D::set_bone_update(BoneUpdate p_bone_update) {
+	ERR_FAIL_INDEX(p_bone_update, BONE_UPDATE_MAX);
+	bone_update = p_bone_update;
+}
+
+XRBodyModifier3D::BoneUpdate XRBodyModifier3D::get_bone_update() const {
+	return bone_update;
+}
+
+void XRBodyModifier3D::set_show_when_tracked(bool p_show_when_tracked) {
+	show_when_tracked = p_show_when_tracked;
+}
+
+bool XRBodyModifier3D::get_show_when_tracked() const {
+	return show_when_tracked;
+}
+
+Skeleton3D *XRBodyModifier3D::get_skeleton() {
+	if (!has_node(target)) {
+		return nullptr;
+	}
+
+	Node *node = get_node(target);
+	if (!node) {
+		return nullptr;
+	}
+
+	Skeleton3D *skeleton = Object::cast_to<Skeleton3D>(node);
+	return skeleton;
+}
+
+void XRBodyModifier3D::_get_joint_data() {
+	// Table of Godot Humanoid bone names.
+	static const String bone_names[XRBodyTracker::JOINT_MAX] = {
+		"Root", // XRBodyTracker::JOINT_ROOT
+
+		// Upper Body Joints.
+		"Hips", // XRBodyTracker::JOINT_HIPS
+		"Spine", // XRBodyTracker::JOINT_SPINE
+		"Chest", // XRBodyTracker::JOINT_CHEST
+		"UpperChest", // XRBodyTracker::JOINT_UPPER_CHEST
+		"Neck", // XRBodyTracker::JOINT_NECK"
+		"Head", // XRBodyTracker::JOINT_HEAD"
+		"HeadTip", // XRBodyTracker::JOINT_HEAD_TIP"
+		"LeftShoulder", // XRBodyTracker::JOINT_LEFT_SHOULDER"
+		"LeftUpperArm", // XRBodyTracker::JOINT_LEFT_UPPER_ARM"
+		"LeftLowerArm", // XRBodyTracker::JOINT_LEFT_LOWER_ARM"
+		"RightShoulder", // XRBodyTracker::JOINT_RIGHT_SHOULDER"
+		"RightUpperArm", // XRBodyTracker::JOINT_RIGHT_UPPER_ARM"
+		"RightLowerArm", // XRBodyTracker::JOINT_RIGHT_LOWER_ARM"
+
+		// Lower Body Joints.
+		"LeftUpperLeg", // XRBodyTracker::JOINT_LEFT_UPPER_LEG
+		"LeftLowerLeg", // XRBodyTracker::JOINT_LEFT_LOWER_LEG
+		"LeftFoot", // XRBodyTracker::JOINT_LEFT_FOOT
+		"LeftToes", // XRBodyTracker::JOINT_LEFT_TOES
+		"RightUpperLeg", // XRBodyTracker::JOINT_RIGHT_UPPER_LEG
+		"RightLowerLeg", // XRBodyTracker::JOINT_RIGHT_LOWER_LEG
+		"RightFoot", // XRBodyTracker::JOINT_RIGHT_FOOT
+		"RightToes", // XRBodyTracker::JOINT_RIGHT_TOES
+
+		// Left Hand Joints.
+		"LeftHand", // XRBodyTracker::JOINT_LEFT_HAND
+		"LeftPalm", // XRBodyTracker::JOINT_LEFT_PALM
+		"LeftWrist", // XRBodyTracker::JOINT_LEFT_WRIST
+		"LeftThumbMetacarpal", // XRBodyTracker::JOINT_LEFT_THUMB_METACARPAL
+		"LeftThumbProximal", // XRBodyTracker::JOINT_LEFT_THUMB_PHALANX_PROXIMAL
+		"LeftThumbDistal", // XRBodyTracker::JOINT_LEFT_THUMB_PHALANX_DISTAL
+		"LeftThumbTip", // XRBodyTracker::JOINT_LEFT_THUMB_TIP
+		"LeftIndexMetacarpal", // XRBodyTracker::JOINT_LEFT_INDEX_FINGER_METACARPAL
+		"LeftIndexProximal", // XRBodyTracker::JOINT_LEFT_INDEX_FINGER_PHALANX_PROXIMAL
+		"LeftIndexIntermediate", // XRBodyTracker::JOINT_LEFT_INDEX_FINGER_PHALANX_INTERMEDIATE
+		"LeftIndexDistal", // XRBodyTracker::JOINT_LEFT_INDEX_FINGER_PHALANX_DISTAL
+		"LeftIndexTip", // XRBodyTracker::JOINT_LEFT_INDEX_FINGER_TIP
+		"LeftMiddleMetacarpal", // XRBodyTracker::JOINT_LEFT_MIDDLE_FINGER_METACARPAL
+		"LeftMiddleProximal", // XRBodyTracker::JOINT_LEFT_MIDDLE_FINGER_PHALANX_PROXIMAL
+		"LeftMiddleIntermediate", // XRBodyTracker::JOINT_LEFT_MIDDLE_FINGER_PHALANX_INTERMEDIATE
+		"LeftMiddleDistal", // XRBodyTracker::JOINT_LEFT_MIDDLE_FINGER_PHALANX_DISTAL
+		"LeftMiddleTip", // XRBodyTracker::JOINT_LEFT_MIDDLE_FINGER_TIP
+		"LeftRingMetacarpal", // XRBodyTracker::JOINT_LEFT_RING_FINGER_METACARPAL
+		"LeftRingProximal", // XRBodyTracker::JOINT_LEFT_RING_FINGER_PHALANX_PROXIMAL
+		"LeftRingIntermediate", // XRBodyTracker::JOINT_LEFT_RING_FINGER_PHALANX_INTERMEDIATE
+		"LeftRingDistal", // XRBodyTracker::JOINT_LEFT_RING_FINGER_PHALANX_DISTAL
+		"LeftRingTip", // XRBodyTracker::JOINT_LEFT_RING_FINGER_TIP
+		"LeftLittleMetacarpal", // XRBodyTracker::JOINT_LEFT_PINKY_FINGER_METACARPAL
+		"LeftLittleProximal", // XRBodyTracker::JOINT_LEFT_PINKY_FINGER_PHALANX_PROXIMAL
+		"LeftLittleIntermediate", // XRBodyTracker::JOINT_LEFT_PINKY_FINGER_PHALANX_INTERMEDIATE
+		"LeftLittleDistal", // XRBodyTracker::JOINT_LEFT_PINKY_FINGER_PHALANX_DISTAL
+		"LeftLittleTip", // XRBodyTracker::JOINT_LEFT_PINKY_FINGER_TIP
+
+		// Right Hand Joints.
+		"RightHand", // XRBodyTracker::JOINT_RIGHT_HAND
+		"RightPalm", // XRBodyTracker::JOINT_RIGHT_PALM
+		"RightWrist", // XRBodyTracker::JOINT_RIGHT_WRIST
+		"RightThumbMetacarpal", // XRBodyTracker::JOINT_RIGHT_THUMB_METACARPAL
+		"RightThumbProximal", // XRBodyTracker::JOINT_RIGHT_THUMB_PHALANX_PROXIMAL
+		"RightThumbDistal", // XRBodyTracker::JOINT_RIGHT_THUMB_PHALANX_DISTAL
+		"RightThumbTip", // XRBodyTracker::JOINT_RIGHT_THUMB_TIP
+		"RightIndexMetacarpal", // XRBodyTracker::JOINT_RIGHT_INDEX_FINGER_METACARPAL
+		"RightIndexProximal", // XRBodyTracker::JOINT_RIGHT_INDEX_FINGER_PHALANX_PROXIMAL
+		"RightIndexIntermediate", // XRBodyTracker::JOINT_RIGHT_INDEX_FINGER_PHALANX_INTERMEDIATE
+		"RightIndexDistal", // XRBodyTracker::JOINT_RIGHT_INDEX_FINGER_PHALANX_DISTAL
+		"RightIndexTip", // XRBodyTracker::JOINT_RIGHT_INDEX_FINGER_TIP
+		"RightMiddleMetacarpal", // XRBodyTracker::JOINT_RIGHT_MIDDLE_FINGER_METACARPAL
+		"RightMiddleProximal", // XRBodyTracker::JOINT_RIGHT_MIDDLE_FINGER_PHALANX_PROXIMAL
+		"RightMiddleIntermediate", // XRBodyTracker::JOINT_RIGHT_MIDDLE_FINGER_PHALANX_INTERMEDIATE
+		"RightMiddleDistal", // XRBodyTracker::JOINT_RIGHT_MIDDLE_FINGER_PHALANX_DISTAL
+		"RightMiddleTip", // XRBodyTracker::JOINT_RIGHT_MIDDLE_FINGER_TIP
+		"RightRingMetacarpal", // XRBodyTracker::JOINT_RIGHT_RING_FINGER_METACARPAL
+		"RightRingProximal", // XRBodyTracker::JOINT_RIGHT_RING_FINGER_PHALANX_PROXIMAL
+		"RightRingIntermediate", // XRBodyTracker::JOINT_RIGHT_RING_FINGER_PHALANX_INTERMEDIATE
+		"RightRingDistal", // XRBodyTracker::JOINT_RIGHT_RING_FINGER_PHALANX_DISTAL
+		"RightRingTip", // XRBodyTracker::JOINT_RIGHT_RING_FINGER_TIP
+		"RightLittleMetacarpal", // XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_METACARPAL
+		"RightLittleProximal", // XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_PHALANX_PROXIMAL
+		"RightLittleIntermediate", // XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_PHALANX_INTERMEDIATE
+		"RightLittleDistal", // XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_PHALANX_DISTAL
+		"RightLittleTip", // XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_TIP
+	};
+
+	// reset JIC.
+	for (int i = 0; i < XRBodyTracker::JOINT_MAX; i++) {
+		joints[i].bone = -1;
+		joints[i].parent_joint = -1;
+	}
+
+	Skeleton3D *skeleton = get_skeleton();
+	if (!skeleton) {
+		return;
+	}
+
+	// Find the skeleton-bones associated with each joint.
+	int bones[XRBodyTracker::JOINT_MAX];
+	for (int i = 0; i < XRBodyTracker::JOINT_MAX; i++) {
+		// Skip upper body joints if not enabled.
+		if (!body_update.has_flag(BODY_UPDATE_UPPER_BODY) && i >= XRBodyTracker::JOINT_HIPS && i <= XRBodyTracker::JOINT_RIGHT_LOWER_ARM) {
+			bones[i] = -1;
+			continue;
+		}
+
+		// Skip lower body joints if not enabled.
+		if (!body_update.has_flag(BODY_UPDATE_LOWER_BODY) && i >= XRBodyTracker::JOINT_LEFT_UPPER_LEG && i <= XRBodyTracker::JOINT_RIGHT_TOES) {
+			bones[i] = -1;
+			continue;
+		}
+
+		// Skip hand joints if not enabled.
+		if (!body_update.has_flag(BODY_UPDATE_HANDS) && i >= XRBodyTracker::JOINT_LEFT_HAND && i <= XRBodyTracker::JOINT_RIGHT_PINKY_FINGER_TIP) {
+			bones[i] = -1;
+			continue;
+		}
+
+		// Find the skeleton bone.
+		bones[i] = skeleton->find_bone(bone_names[i]);
+		if (bones[i] == -1) {
+			WARN_PRINT(vformat("Couldn't obtain bone for %s", bone_names[i]));
+		}
+	}
+
+	// If the root bone is not found then use the skeleton root bone.
+	if (bones[XRBodyTracker::JOINT_ROOT] == -1) {
+		bones[XRBodyTracker::JOINT_ROOT] = 0;
+	}
+
+	// Assemble the joint relationship to the available skeleton bones.
+	for (int i = 0; i < XRBodyTracker::JOINT_MAX; i++) {
+		// Get the skeleton bone (skip if not found).
+		const int bone = bones[i];
+		if (bone == -1) {
+			continue;
+		}
+
+		// Find the parent skeleton-bone.
+		const int parent_bone = skeleton->get_bone_parent(bone);
+		if (parent_bone == -1) {
+			// If no parent skeleton-bone exists then drive this relative to the root joint.
+			joints[i].bone = bone;
+			joints[i].parent_joint = XRBodyTracker::JOINT_ROOT;
+			continue;
+		}
+
+		// Find the joint associated with the parent skeleton-bone.
+		for (int j = 0; j < XRBodyTracker::JOINT_MAX; ++j) {
+			if (bones[j] == parent_bone) {
+				// If a parent joint is found then drive this bone relative to it.
+				joints[i].bone = bone;
+				joints[i].parent_joint = j;
+				break;
+			}
+		}
+	}
+}
+
+void XRBodyModifier3D::_update_skeleton() {
+	Skeleton3D *skeleton = get_skeleton();
+	if (!skeleton) {
+		return;
+	}
+
+	XRServer *xr_server = XRServer::get_singleton();
+	if (!xr_server) {
+		return;
+	}
+
+	Ref<XRBodyTracker> tracker = xr_server->get_body_tracker(tracker_name);
+	if (tracker.is_null()) {
+		return;
+	}
+
+	// Handle no tracking data.
+	if (!tracker->get_has_tracking_data()) {
+		// If tracking-state determines visibility then hide the node.
+		if (show_when_tracked) {
+			set_visible(false);
+		}
+		return;
+	}
+
+	// Read the relevant tracking data.
+	bool has_valid_data[XRBodyTracker::JOINT_MAX];
+	Transform3D transforms[XRBodyTracker::JOINT_MAX];
+	Transform3D inv_transforms[XRBodyTracker::JOINT_MAX];
+	const float ws = xr_server->get_world_scale();
+	for (int joint = 0; joint < XRBodyTracker::JOINT_MAX; joint++) {
+		BitField<XRBodyTracker::JointFlags> flags = tracker->get_joint_flags(static_cast<XRBodyTracker::Joint>(joint));
+		has_valid_data[joint] = flags.has_flag(XRBodyTracker::JOINT_FLAG_ORIENTATION_VALID) && flags.has_flag(XRBodyTracker::JOINT_FLAG_POSITION_VALID);
+
+		if (has_valid_data[joint]) {
+			transforms[joint] = tracker->get_joint_transform(static_cast<XRBodyTracker::Joint>(joint));
+			transforms[joint].origin *= ws;
+			inv_transforms[joint] = transforms[joint].inverse();
+		}
+	}
+
+	// Handle root joint not tracked.
+	if (!has_valid_data[XRBodyTracker::JOINT_ROOT]) {
+		// If tracking-state determines visibility then hide the node.
+		if (show_when_tracked) {
+			set_visible(false);
+		}
+		return;
+	}
+
+	// Apply the joint information to the skeleton.
+	for (int joint = 0; joint < XRBodyTracker::JOINT_MAX; joint++) {
+		// Skip if no valid joint data
+		if (!has_valid_data[joint]) {
+			continue;
+		}
+
+		// Get the skeleton bone (skip if none).
+		const int bone = joints[joint].bone;
+		if (bone == -1) {
+			continue;
+		}
+
+		// Calculate the relative relationship to the parent bone joint.
+		const int parent_joint = joints[joint].parent_joint;
+		const Transform3D relative_transform = inv_transforms[parent_joint] * transforms[joint];
+
+		// Update the bone position if enabled by update mode.
+		if (bone_update == BONE_UPDATE_FULL) {
+			skeleton->set_bone_pose_position(joints[joint].bone, relative_transform.origin);
+		}
+
+		// Always update the bone rotation.
+		skeleton->set_bone_pose_rotation(joints[joint].bone, Quaternion(relative_transform.basis));
+	}
+
+	// Transform to the skeleton pose.
+	set_transform(transforms[XRBodyTracker::JOINT_ROOT]);
+
+	// If tracking-state determines visibility then show the node.
+	if (show_when_tracked) {
+		set_visible(true);
+	}
+}
+
+void XRBodyModifier3D::_tracker_changed(const StringName &p_tracker_name, const Ref<XRBodyTracker> &p_tracker) {
+	if (tracker_name == p_tracker_name) {
+		_get_joint_data();
+	}
+}
+
+void XRBodyModifier3D::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			XRServer *xr_server = XRServer::get_singleton();
+			if (xr_server) {
+				xr_server->connect("body_tracker_added", callable_mp(this, &XRBodyModifier3D::_tracker_changed));
+				xr_server->connect("body_tracker_updated", callable_mp(this, &XRBodyModifier3D::_tracker_changed));
+				xr_server->connect("body_tracker_removed", callable_mp(this, &XRBodyModifier3D::_tracker_changed).bind(Ref<XRBodyTracker>()));
+			}
+
+			_get_joint_data();
+
+			set_process_internal(true);
+		} break;
+		case NOTIFICATION_EXIT_TREE: {
+			XRServer *xr_server = XRServer::get_singleton();
+			if (xr_server) {
+				xr_server->disconnect("body_tracker_added", callable_mp(this, &XRBodyModifier3D::_tracker_changed));
+				xr_server->disconnect("body_tracker_updated", callable_mp(this, &XRBodyModifier3D::_tracker_changed));
+				xr_server->disconnect("body_tracker_removed", callable_mp(this, &XRBodyModifier3D::_tracker_changed).bind(Ref<XRBodyTracker>()));
+			}
+
+			set_process_internal(false);
+
+			for (int i = 0; i < XRBodyTracker::JOINT_MAX; i++) {
+				joints[i].bone = -1;
+				joints[i].parent_joint = -1;
+			}
+		} break;
+		case NOTIFICATION_INTERNAL_PROCESS: {
+			_update_skeleton();
+		} break;
+		default: {
+		} break;
+	}
+}

scene/3d/xr_body_modifier_3d.h

@@ -0,0 +1,102 @@
+/**************************************************************************/
+/*  xr_body_modifier_3d.h                                                 */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef XR_BODY_MODIFIER_3D_H
+#define XR_BODY_MODIFIER_3D_H
+
+#include "scene/3d/node_3d.h"
+#include "servers/xr/xr_body_tracker.h"
+
+class Skeleton3D;
+
+/**
+	The XRBodyModifier3D node drives a body skeleton using body tracking
+	data from an XRBodyTracker instance.
+ */
+
+class XRBodyModifier3D : public Node3D {
+	GDCLASS(XRBodyModifier3D, Node3D);
+
+public:
+	enum BodyUpdate {
+		BODY_UPDATE_UPPER_BODY = 1,
+		BODY_UPDATE_LOWER_BODY = 2,
+		BODY_UPDATE_HANDS = 4,
+	};
+
+	enum BoneUpdate {
+		BONE_UPDATE_FULL,
+		BONE_UPDATE_ROTATION_ONLY,
+		BONE_UPDATE_MAX
+	};
+
+	void set_body_tracker(const StringName &p_tracker_name);
+	StringName get_body_tracker() const;
+
+	void set_target(const NodePath &p_target);
+	NodePath get_target() const;
+
+	void set_body_update(BitField<BodyUpdate> p_body_update);
+	BitField<BodyUpdate> get_body_update() const;
+
+	void set_bone_update(BoneUpdate p_bone_update);
+	BoneUpdate get_bone_update() const;
+
+	void set_show_when_tracked(bool p_show_when_tracked);
+	bool get_show_when_tracked() const;
+
+	void _notification(int p_what);
+
+protected:
+	static void _bind_methods();
+
+private:
+	struct JointData {
+		int bone = -1;
+		int parent_joint = -1;
+	};
+
+	StringName tracker_name = "/user/body";
+	NodePath target;
+	BitField<BodyUpdate> body_update = BODY_UPDATE_UPPER_BODY | BODY_UPDATE_LOWER_BODY | BODY_UPDATE_HANDS;
+	BoneUpdate bone_update = BONE_UPDATE_FULL;
+	bool show_when_tracked = true;
+	JointData joints[XRBodyTracker::JOINT_MAX];
+
+	Skeleton3D *get_skeleton();
+	void _get_joint_data();
+	void _update_skeleton();
+	void _tracker_changed(const StringName &p_tracker_name, const Ref<XRBodyTracker> &p_tracker);
+};
+
+VARIANT_BITFIELD_CAST(XRBodyModifier3D::BodyUpdate)
+VARIANT_ENUM_CAST(XRBodyModifier3D::BoneUpdate)
+
+#endif // XR_BODY_MODIFIER_3D_H

scene/register_scene_types.cpp

@@ -279,6 +279,7 @@
 #include "scene/3d/visible_on_screen_notifier_3d.h"
 #include "scene/3d/voxel_gi.h"
 #include "scene/3d/world_environment.h"
+#include "scene/3d/xr_body_modifier_3d.h"
 #include "scene/3d/xr_face_modifier_3d.h"
 #include "scene/3d/xr_hand_modifier_3d.h"
 #include "scene/3d/xr_nodes.h"
@@ -541,6 +542,7 @@ void register_scene_types() {
 	GDREGISTER_CLASS(XRController3D);
 	GDREGISTER_CLASS(XRAnchor3D);
 	GDREGISTER_CLASS(XROrigin3D);
+	GDREGISTER_CLASS(XRBodyModifier3D);
 	GDREGISTER_CLASS(XRHandModifier3D);
 	GDREGISTER_CLASS(XRFaceModifier3D);
 	GDREGISTER_CLASS(MeshInstance3D);

servers/register_server_types.cpp

@@ -76,6 +76,7 @@
 #include "text/text_server_dummy.h"
 #include "text/text_server_extension.h"
 #include "text_server.h"
+#include "xr/xr_body_tracker.h"
 #include "xr/xr_face_tracker.h"
 #include "xr/xr_hand_tracker.h"
 #include "xr/xr_interface.h"
@@ -173,6 +174,7 @@ void register_server_types() {
 
 	GDREGISTER_ABSTRACT_CLASS(RenderingDevice);
 
+	GDREGISTER_CLASS(XRBodyTracker);
 	GDREGISTER_ABSTRACT_CLASS(XRInterface);
 	GDREGISTER_CLASS(XRHandTracker);
 	GDREGISTER_CLASS(XRInterfaceExtension); // can't register this as virtual because we need a creation function for our extensions.

servers/xr/xr_body_tracker.cpp

@@ -0,0 +1,171 @@
+/**************************************************************************/
+/*  xr_body_tracker.cpp                                                   */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include "xr_body_tracker.h"
+
+void XRBodyTracker::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_has_tracking_data", "has_data"), &XRBodyTracker::set_has_tracking_data);
+	ClassDB::bind_method(D_METHOD("get_has_tracking_data"), &XRBodyTracker::get_has_tracking_data);
+
+	ClassDB::bind_method(D_METHOD("set_body_flags", "flags"), &XRBodyTracker::set_body_flags);
+	ClassDB::bind_method(D_METHOD("get_body_flags"), &XRBodyTracker::get_body_flags);
+
+	ClassDB::bind_method(D_METHOD("set_joint_flags", "joint", "flags"), &XRBodyTracker::set_joint_flags);
+	ClassDB::bind_method(D_METHOD("get_joint_flags", "joint"), &XRBodyTracker::get_joint_flags);
+
+	ClassDB::bind_method(D_METHOD("set_joint_transform", "joint", "transform"), &XRBodyTracker::set_joint_transform);
+	ClassDB::bind_method(D_METHOD("get_joint_transform", "joint"), &XRBodyTracker::get_joint_transform);
+
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "has_tracking_data", PROPERTY_HINT_NONE), "set_has_tracking_data", "get_has_tracking_data");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "body_flags", PROPERTY_HINT_FLAGS, "Upper Body,Lower Body,Hands"), "set_body_flags", "get_body_flags");
+
+	BIND_BITFIELD_FLAG(BODY_FLAG_UPPER_BODY_SUPPORTED);
+	BIND_BITFIELD_FLAG(BODY_FLAG_LOWER_BODY_SUPPORTED);
+	BIND_BITFIELD_FLAG(BODY_FLAG_HANDS_SUPPORTED);
+
+	BIND_ENUM_CONSTANT(JOINT_ROOT);
+	BIND_ENUM_CONSTANT(JOINT_HIPS);
+	BIND_ENUM_CONSTANT(JOINT_SPINE);
+	BIND_ENUM_CONSTANT(JOINT_CHEST);
+	BIND_ENUM_CONSTANT(JOINT_UPPER_CHEST);
+	BIND_ENUM_CONSTANT(JOINT_NECK);
+	BIND_ENUM_CONSTANT(JOINT_HEAD);
+	BIND_ENUM_CONSTANT(JOINT_HEAD_TIP);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_SHOULDER);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_UPPER_ARM);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_LOWER_ARM);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_SHOULDER);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_UPPER_ARM);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_LOWER_ARM);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_UPPER_LEG);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_LOWER_LEG);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_FOOT);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_TOES);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_UPPER_LEG);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_LOWER_LEG);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_FOOT);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_TOES);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_HAND);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PALM);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_WRIST);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_THUMB_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_THUMB_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_THUMB_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_THUMB_TIP);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_INDEX_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_INDEX_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_INDEX_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_INDEX_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_INDEX_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_MIDDLE_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_MIDDLE_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_MIDDLE_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_MIDDLE_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_MIDDLE_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_RING_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_RING_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_RING_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_RING_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_RING_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PINKY_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PINKY_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PINKY_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PINKY_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_LEFT_PINKY_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_HAND);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PALM);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_WRIST);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_THUMB_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_THUMB_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_THUMB_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_THUMB_TIP);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_INDEX_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_INDEX_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_INDEX_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_INDEX_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_INDEX_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_MIDDLE_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_MIDDLE_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_MIDDLE_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_MIDDLE_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_MIDDLE_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_RING_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_RING_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_RING_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_RING_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_RING_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PINKY_FINGER_METACARPAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PINKY_FINGER_PHALANX_PROXIMAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PINKY_FINGER_PHALANX_INTERMEDIATE);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PINKY_FINGER_PHALANX_DISTAL);
+	BIND_ENUM_CONSTANT(JOINT_RIGHT_PINKY_FINGER_TIP);
+	BIND_ENUM_CONSTANT(JOINT_MAX);
+
+	BIND_BITFIELD_FLAG(JOINT_FLAG_ORIENTATION_VALID);
+	BIND_BITFIELD_FLAG(JOINT_FLAG_ORIENTATION_TRACKED);
+	BIND_BITFIELD_FLAG(JOINT_FLAG_POSITION_VALID);
+	BIND_BITFIELD_FLAG(JOINT_FLAG_POSITION_TRACKED);
+}
+
+void XRBodyTracker::set_has_tracking_data(bool p_has_tracking_data) {
+	has_tracking_data = p_has_tracking_data;
+}
+
+bool XRBodyTracker::get_has_tracking_data() const {
+	return has_tracking_data;
+}
+
+void XRBodyTracker::set_body_flags(BitField<BodyFlags> p_body_flags) {
+	body_flags = p_body_flags;
+}
+
+BitField<XRBodyTracker::BodyFlags> XRBodyTracker::get_body_flags() const {
+	return body_flags;
+}
+
+void XRBodyTracker::set_joint_flags(Joint p_joint, BitField<JointFlags> p_flags) {
+	ERR_FAIL_INDEX(p_joint, JOINT_MAX);
+	joint_flags[p_joint] = p_flags;
+}
+
+BitField<XRBodyTracker::JointFlags> XRBodyTracker::get_joint_flags(Joint p_joint) const {
+	ERR_FAIL_INDEX_V(p_joint, JOINT_MAX, BitField<JointFlags>());
+	return joint_flags[p_joint];
+}
+
+void XRBodyTracker::set_joint_transform(Joint p_joint, const Transform3D &p_transform) {
+	ERR_FAIL_INDEX(p_joint, JOINT_MAX);
+	joint_transforms[p_joint] = p_transform;
+}
+
+Transform3D XRBodyTracker::get_joint_transform(Joint p_joint) const {
+	ERR_FAIL_INDEX_V(p_joint, JOINT_MAX, Transform3D());
+	return joint_transforms[p_joint];
+}

servers/xr/xr_body_tracker.h

@@ -0,0 +1,170 @@
+/**************************************************************************/
+/*  xr_body_tracker.h                                                     */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef XR_BODY_TRACKER_H
+#define XR_BODY_TRACKER_H
+
+#include "core/object/ref_counted.h"
+
+class XRBodyTracker : public RefCounted {
+	GDCLASS(XRBodyTracker, RefCounted);
+	_THREAD_SAFE_CLASS_
+
+public:
+	enum BodyFlags {
+		BODY_FLAG_UPPER_BODY_SUPPORTED = 1,
+		BODY_FLAG_LOWER_BODY_SUPPORTED = 2,
+		BODY_FLAG_HANDS_SUPPORTED = 4,
+	};
+
+	enum Joint {
+		JOINT_ROOT,
+
+		// Upper Body Joints
+		JOINT_HIPS,
+		JOINT_SPINE,
+		JOINT_CHEST,
+		JOINT_UPPER_CHEST,
+		JOINT_NECK,
+		JOINT_HEAD,
+		JOINT_HEAD_TIP,
+		JOINT_LEFT_SHOULDER,
+		JOINT_LEFT_UPPER_ARM,
+		JOINT_LEFT_LOWER_ARM,
+		JOINT_RIGHT_SHOULDER,
+		JOINT_RIGHT_UPPER_ARM,
+		JOINT_RIGHT_LOWER_ARM,
+
+		// Lower Body Joints
+		JOINT_LEFT_UPPER_LEG,
+		JOINT_LEFT_LOWER_LEG,
+		JOINT_LEFT_FOOT,
+		JOINT_LEFT_TOES,
+		JOINT_RIGHT_UPPER_LEG,
+		JOINT_RIGHT_LOWER_LEG,
+		JOINT_RIGHT_FOOT,
+		JOINT_RIGHT_TOES,
+
+		// Left Hand Joints
+		JOINT_LEFT_HAND,
+		JOINT_LEFT_PALM,
+		JOINT_LEFT_WRIST,
+		JOINT_LEFT_THUMB_METACARPAL,
+		JOINT_LEFT_THUMB_PHALANX_PROXIMAL,
+		JOINT_LEFT_THUMB_PHALANX_DISTAL,
+		JOINT_LEFT_THUMB_TIP,
+		JOINT_LEFT_INDEX_FINGER_METACARPAL,
+		JOINT_LEFT_INDEX_FINGER_PHALANX_PROXIMAL,
+		JOINT_LEFT_INDEX_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_LEFT_INDEX_FINGER_PHALANX_DISTAL,
+		JOINT_LEFT_INDEX_FINGER_TIP,
+		JOINT_LEFT_MIDDLE_FINGER_METACARPAL,
+		JOINT_LEFT_MIDDLE_FINGER_PHALANX_PROXIMAL,
+		JOINT_LEFT_MIDDLE_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_LEFT_MIDDLE_FINGER_PHALANX_DISTAL,
+		JOINT_LEFT_MIDDLE_FINGER_TIP,
+		JOINT_LEFT_RING_FINGER_METACARPAL,
+		JOINT_LEFT_RING_FINGER_PHALANX_PROXIMAL,
+		JOINT_LEFT_RING_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_LEFT_RING_FINGER_PHALANX_DISTAL,
+		JOINT_LEFT_RING_FINGER_TIP,
+		JOINT_LEFT_PINKY_FINGER_METACARPAL,
+		JOINT_LEFT_PINKY_FINGER_PHALANX_PROXIMAL,
+		JOINT_LEFT_PINKY_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_LEFT_PINKY_FINGER_PHALANX_DISTAL,
+		JOINT_LEFT_PINKY_FINGER_TIP,
+
+		// Right Hand Joints
+		JOINT_RIGHT_HAND,
+		JOINT_RIGHT_PALM,
+		JOINT_RIGHT_WRIST,
+		JOINT_RIGHT_THUMB_METACARPAL,
+		JOINT_RIGHT_THUMB_PHALANX_PROXIMAL,
+		JOINT_RIGHT_THUMB_PHALANX_DISTAL,
+		JOINT_RIGHT_THUMB_TIP,
+		JOINT_RIGHT_INDEX_FINGER_METACARPAL,
+		JOINT_RIGHT_INDEX_FINGER_PHALANX_PROXIMAL,
+		JOINT_RIGHT_INDEX_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_RIGHT_INDEX_FINGER_PHALANX_DISTAL,
+		JOINT_RIGHT_INDEX_FINGER_TIP,
+		JOINT_RIGHT_MIDDLE_FINGER_METACARPAL,
+		JOINT_RIGHT_MIDDLE_FINGER_PHALANX_PROXIMAL,
+		JOINT_RIGHT_MIDDLE_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_RIGHT_MIDDLE_FINGER_PHALANX_DISTAL,
+		JOINT_RIGHT_MIDDLE_FINGER_TIP,
+		JOINT_RIGHT_RING_FINGER_METACARPAL,
+		JOINT_RIGHT_RING_FINGER_PHALANX_PROXIMAL,
+		JOINT_RIGHT_RING_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_RIGHT_RING_FINGER_PHALANX_DISTAL,
+		JOINT_RIGHT_RING_FINGER_TIP,
+		JOINT_RIGHT_PINKY_FINGER_METACARPAL,
+		JOINT_RIGHT_PINKY_FINGER_PHALANX_PROXIMAL,
+		JOINT_RIGHT_PINKY_FINGER_PHALANX_INTERMEDIATE,
+		JOINT_RIGHT_PINKY_FINGER_PHALANX_DISTAL,
+		JOINT_RIGHT_PINKY_FINGER_TIP,
+
+		JOINT_MAX,
+	};
+
+	enum JointFlags {
+		JOINT_FLAG_ORIENTATION_VALID = 1,
+		JOINT_FLAG_ORIENTATION_TRACKED = 2,
+		JOINT_FLAG_POSITION_VALID = 4,
+		JOINT_FLAG_POSITION_TRACKED = 8,
+	};
+
+	void set_has_tracking_data(bool p_has_tracking_data);
+	bool get_has_tracking_data() const;
+
+	void set_body_flags(BitField<BodyFlags> p_body_flags);
+	BitField<BodyFlags> get_body_flags() const;
+
+	void set_joint_flags(Joint p_joint, BitField<JointFlags> p_flags);
+	BitField<JointFlags> get_joint_flags(Joint p_joint) const;
+
+	void set_joint_transform(Joint p_joint, const Transform3D &p_transform);
+	Transform3D get_joint_transform(Joint p_joint) const;
+
+protected:
+	static void _bind_methods();
+
+private:
+	bool has_tracking_data = false;
+	BitField<BodyFlags> body_flags;
+
+	BitField<JointFlags> joint_flags[JOINT_MAX];
+	Transform3D joint_transforms[JOINT_MAX];
+};
+
+VARIANT_BITFIELD_CAST(XRBodyTracker::BodyFlags)
+VARIANT_ENUM_CAST(XRBodyTracker::Joint)
+VARIANT_BITFIELD_CAST(XRBodyTracker::JointFlags)
+
+#endif // XR_BODY_TRACKER_H

servers/xr_server.cpp

@@ -30,6 +30,7 @@
 
 #include "xr_server.h"
 #include "core/config/project_settings.h"
+#include "xr/xr_body_tracker.h"
 #include "xr/xr_face_tracker.h"
 #include "xr/xr_hand_tracker.h"
 #include "xr/xr_interface.h"
@@ -86,6 +87,11 @@ void XRServer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_face_trackers"), &XRServer::get_face_trackers);
 	ClassDB::bind_method(D_METHOD("get_face_tracker", "tracker_name"), &XRServer::get_face_tracker);
 
+	ClassDB::bind_method(D_METHOD("add_body_tracker", "tracker_name", "body_tracker"), &XRServer::add_body_tracker);
+	ClassDB::bind_method(D_METHOD("remove_body_tracker", "tracker_name"), &XRServer::remove_body_tracker);
+	ClassDB::bind_method(D_METHOD("get_body_trackers"), &XRServer::get_body_trackers);
+	ClassDB::bind_method(D_METHOD("get_body_tracker", "tracker_name"), &XRServer::get_body_tracker);
+
 	ClassDB::bind_method(D_METHOD("get_primary_interface"), &XRServer::get_primary_interface);
 	ClassDB::bind_method(D_METHOD("set_primary_interface", "interface"), &XRServer::set_primary_interface);
 
@@ -117,6 +123,10 @@ void XRServer::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("face_tracker_added", PropertyInfo(Variant::STRING_NAME, "tracker_name"), PropertyInfo(Variant::OBJECT, "face_tracker", PROPERTY_HINT_RESOURCE_TYPE, "XRFaceTracker")));
 	ADD_SIGNAL(MethodInfo("face_tracker_updated", PropertyInfo(Variant::STRING_NAME, "tracker_name"), PropertyInfo(Variant::OBJECT, "face_tracker", PROPERTY_HINT_RESOURCE_TYPE, "XRFaceTracker")));
 	ADD_SIGNAL(MethodInfo("face_tracker_removed", PropertyInfo(Variant::STRING_NAME, "tracker_name")));
+
+	ADD_SIGNAL(MethodInfo("body_tracker_added", PropertyInfo(Variant::STRING_NAME, "tracker_name"), PropertyInfo(Variant::OBJECT, "body_tracker", PROPERTY_HINT_RESOURCE_TYPE, "XRBodyTracker")));
+	ADD_SIGNAL(MethodInfo("body_tracker_updated", PropertyInfo(Variant::STRING_NAME, "tracker_name"), PropertyInfo(Variant::OBJECT, "body_tracker", PROPERTY_HINT_RESOURCE_TYPE, "XRBodyTracker")));
+	ADD_SIGNAL(MethodInfo("body_tracker_removed", PropertyInfo(Variant::STRING_NAME, "tracker_name")));
 };
 
 double XRServer::get_world_scale() const {
@@ -448,6 +458,44 @@ Ref<XRFaceTracker> XRServer::get_face_tracker(const StringName &p_tracker_name)
 	return face_trackers[p_tracker_name];
 }
 
+void XRServer::add_body_tracker(const StringName &p_tracker_name, Ref<XRBodyTracker> p_body_tracker) {
+	ERR_FAIL_COND(p_body_tracker.is_null());
+
+	if (!body_trackers.has(p_tracker_name)) {
+		// We don't have a tracker with this name, we're going to add it.
+		body_trackers[p_tracker_name] = p_body_tracker;
+		emit_signal(SNAME("body_tracker_added"), p_tracker_name, p_body_tracker);
+	} else if (body_trackers[p_tracker_name] != p_body_tracker) {
+		// We already have a tracker with this name, we're going to replace it.
+		body_trackers[p_tracker_name] = p_body_tracker;
+		emit_signal(SNAME("body_tracker_updated"), p_tracker_name, p_body_tracker);
+	}
+}
+
+void XRServer::remove_body_tracker(const StringName &p_tracker_name) {
+	// Skip if no face tracker is found.
+	if (!body_trackers.has(p_tracker_name)) {
+		return;
+	}
+
+	// Send the removed signal, then remove the face tracker.
+	emit_signal(SNAME("body_tracker_removed"), p_tracker_name);
+	body_trackers.erase(p_tracker_name);
+}
+
+Dictionary XRServer::get_body_trackers() const {
+	return body_trackers;
+}
+
+Ref<XRBodyTracker> XRServer::get_body_tracker(const StringName &p_tracker_name) const {
+	// Skip if no tracker is found.
+	if (!body_trackers.has(p_tracker_name)) {
+		return Ref<XRBodyTracker>();
+	}
+
+	return body_trackers[p_tracker_name];
+}
+
 void XRServer::_process() {
 	// called from our main game loop before we handle physics and game logic
 	// note that we can have multiple interfaces active if we have interfaces that purely handle tracking

servers/xr_server.h

@@ -41,6 +41,7 @@ class XRInterface;
 class XRPositionalTracker;
 class XRHandTracker;
 class XRFaceTracker;
+class XRBodyTracker;
 
 /**
 	The XR server is a singleton object that gives access to the various
@@ -89,6 +90,7 @@ private:
 	Dictionary trackers;
 	Dictionary hand_trackers;
 	Dictionary face_trackers;
+	Dictionary body_trackers;
 
 	Ref<XRInterface> primary_interface; /* we'll identify one interface as primary, this will be used by our viewports */
 
@@ -203,6 +205,14 @@ public:
 	Dictionary get_face_trackers() const;
 	Ref<XRFaceTracker> get_face_tracker(const StringName &p_tracker_name) const;
 
+	/*
+		Body trackers are objects that expose the tracked joints of a body.
+	 */
+	void add_body_tracker(const StringName &p_tracker_name, Ref<XRBodyTracker> p_face_tracker);
+	void remove_body_tracker(const StringName &p_tracker_name);
+	Dictionary get_body_trackers() const;
+	Ref<XRBodyTracker> get_body_tracker(const StringName &p_tracker_name) const;
+
 	// Process is called before we handle our physics process and game process. This is where our interfaces will update controller data and such.
 	void _process();