Adding OpenXR hand tracking support

2 files changed, 400 insertions, 0 deletions

diff --git a/modules/openxr/scene/openxr_hand.cpp b/modules/openxr/scene/openxr_hand.cpp
new file mode 100644
index 0000000000..2ae13a1026
--- /dev/null
+++ b/modules/openxr/scene/openxr_hand.cpp
@@ -0,0 +1,307 @@
+/*************************************************************************/
+/*  openxr_hand.cpp                                                      */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* 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 "../extensions/openxr_hand_tracking_extension.h"
+#include "../openxr_api.h"
+
+#include "openxr_hand.h"
+#include "scene/3d/skeleton_3d.h"
+#include "servers/xr_server.h"
+
+void OpenXRHand::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_hand", "hand"), &OpenXRHand::set_hand);
+	ClassDB::bind_method(D_METHOD("get_hand"), &OpenXRHand::get_hand);
+
+	ClassDB::bind_method(D_METHOD("set_hand_skeleton", "hand_skeleton"), &OpenXRHand::set_hand_skeleton);
+	ClassDB::bind_method(D_METHOD("get_hand_skeleton"), &OpenXRHand::get_hand_skeleton);
+
+	ClassDB::bind_method(D_METHOD("set_motion_range", "motion_range"), &OpenXRHand::set_motion_range);
+	ClassDB::bind_method(D_METHOD("get_motion_range"), &OpenXRHand::get_motion_range);
+
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "hand", PROPERTY_HINT_ENUM, "Left,Right"), "set_hand", "get_hand");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "motion_range", PROPERTY_HINT_ENUM, "Unobstructed,Conform to controller"), "set_motion_range", "get_motion_range");
+	ADD_PROPERTY(PropertyInfo(Variant::NODE_PATH, "hand_skeleton", PROPERTY_HINT_NODE_PATH_VALID_TYPES, "Skeleton3D"), "set_hand_skeleton", "get_hand_skeleton");
+
+	BIND_ENUM_CONSTANT(HAND_LEFT);
+	BIND_ENUM_CONSTANT(HAND_RIGHT);
+	BIND_ENUM_CONSTANT(HAND_MAX);
+
+	BIND_ENUM_CONSTANT(MOTION_RANGE_UNOBSTRUCTED);
+	BIND_ENUM_CONSTANT(MOTION_RANGE_CONFORM_TO_CONTROLLER);
+	BIND_ENUM_CONSTANT(MOTION_RANGE_MAX);
+}
+
+OpenXRHand::OpenXRHand() {
+	openxr_api = OpenXRAPI::get_singleton();
+	hand_tracking_ext = OpenXRHandTrackingExtension::get_singleton();
+}
+
+void OpenXRHand::set_hand(const Hands p_hand) {
+	ERR_FAIL_INDEX(p_hand, HAND_MAX);
+
+	hand = p_hand;
+}
+
+OpenXRHand::Hands OpenXRHand::get_hand() const {
+	return hand;
+}
+
+void OpenXRHand::set_hand_skeleton(const NodePath &p_hand_skeleton) {
+	hand_skeleton = p_hand_skeleton;
+
+	// TODO if inside tree call _get_bones()
+}
+
+void OpenXRHand::set_motion_range(const MotionRange p_motion_range) {
+	ERR_FAIL_INDEX(p_motion_range, MOTION_RANGE_MAX);
+	motion_range = p_motion_range;
+
+	_set_motion_range();
+}
+
+OpenXRHand::MotionRange OpenXRHand::get_motion_range() const {
+	return motion_range;
+}
+
+NodePath OpenXRHand::get_hand_skeleton() const {
+	return hand_skeleton;
+}
+
+void OpenXRHand::_set_motion_range() {
+	if (!hand_tracking_ext) {
+		return;
+	}
+
+	XrHandJointsMotionRangeEXT xr_motion_range;
+	switch (motion_range) {
+		case MOTION_RANGE_UNOBSTRUCTED:
+			xr_motion_range = XR_HAND_JOINTS_MOTION_RANGE_UNOBSTRUCTED_EXT;
+			break;
+		case MOTION_RANGE_CONFORM_TO_CONTROLLER:
+			xr_motion_range = XR_HAND_JOINTS_MOTION_RANGE_CONFORMING_TO_CONTROLLER_EXT;
+			break;
+		default:
+			xr_motion_range = XR_HAND_JOINTS_MOTION_RANGE_CONFORMING_TO_CONTROLLER_EXT;
+			break;
+	}
+
+	hand_tracking_ext->set_motion_range(hand, xr_motion_range);
+}
+
+Skeleton3D *OpenXRHand::get_skeleton() {
+	if (!has_node(hand_skeleton)) {
+		return nullptr;
+	}
+
+	Node *node = get_node(hand_skeleton);
+	if (!node) {
+		return nullptr;
+	}
+
+	Skeleton3D *skeleton = Object::cast_to<Skeleton3D>(node);
+	return skeleton;
+}
+
+void OpenXRHand::_get_bones() {
+	const char *bone_names[XR_HAND_JOINT_COUNT_EXT] = {
+		"Palm",
+		"Wrist",
+		"Thumb_Metacarpal",
+		"Thumb_Proximal",
+		"Thumb_Distal",
+		"Thumb_Tip",
+		"Index_Metacarpal",
+		"Index_Proximal",
+		"Index_Intermediate",
+		"Index_Distal",
+		"Index_Tip",
+		"Middle_Metacarpal",
+		"Middle_Proximal",
+		"Middle_Intermediate",
+		"Middle_Distal",
+		"Middle_Tip",
+		"Ring_Metacarpal",
+		"Ring_Proximal",
+		"Ring_Intermediate",
+		"Ring_Distal",
+		"Ring_Tip",
+		"Little_Metacarpal",
+		"Little_Proximal",
+		"Little_Intermediate",
+		"Little_Distal",
+		"Little_Tip",
+	};
+
+	// reset JIC
+	for (int i = 0; i < XR_HAND_JOINT_COUNT_EXT; i++) {
+		bones[i] = -1;
+	}
+
+	Skeleton3D *skeleton = get_skeleton();
+	if (!skeleton) {
+		return;
+	}
+
+	// We cast to spatials which should allow us to use any subclass of that.
+	for (int i = 0; i < XR_HAND_JOINT_COUNT_EXT; i++) {
+		String bone_name = bone_names[i];
+		if (hand == 0) {
+			bone_name += String("_L");
+		} else {
+			bone_name += String("_R");
+		}
+
+		bones[i] = skeleton->find_bone(bone_name);
+		if (bones[i] == -1) {
+			print_line("Couldn't obtain bone for", bone_name);
+		}
+	}
+}
+
+void OpenXRHand::_update_skeleton() {
+	if (openxr_api == nullptr || !openxr_api->is_initialized()) {
+		return;
+	} else if (hand_tracking_ext == nullptr || !hand_tracking_ext->get_active()) {
+		return;
+	}
+
+	Skeleton3D *skeleton = get_skeleton();
+	if (!skeleton) {
+		return;
+	}
+
+	// we cache our transforms so we can quickly calculate local transforms
+	XRPose::TrackingConfidence confidences[XR_HAND_JOINT_COUNT_EXT];
+	Quaternion quaternions[XR_HAND_JOINT_COUNT_EXT];
+	Quaternion inv_quaternions[XR_HAND_JOINT_COUNT_EXT];
+	Vector3 positions[XR_HAND_JOINT_COUNT_EXT];
+
+	const OpenXRHandTrackingExtension::HandTracker *hand_tracker = hand_tracking_ext->get_hand_tracker(hand);
+	const float ws = XRServer::get_singleton()->get_world_scale();
+
+	if (hand_tracker->is_initialised && hand_tracker->locations.isActive) {
+		for (int i = 0; i < XR_HAND_JOINT_COUNT_EXT; i++) {
+			confidences[i] = XRPose::XR_TRACKING_CONFIDENCE_NONE;
+			quaternions[i] = Quaternion();
+			positions[i] = Vector3();
+
+			const auto &location = hand_tracker->joint_locations[i];
+			const auto &pose = location.pose;
+
+			if (location.locationFlags & XR_SPACE_LOCATION_ORIENTATION_VALID_BIT) {
+				if (pose.orientation.x != 0 || pose.orientation.y != 0 || pose.orientation.y != 0 || pose.orientation.w != 0) {
+					quaternions[i] = Quaternion(pose.orientation.x, pose.orientation.y, pose.orientation.z, pose.orientation.w);
+					inv_quaternions[i] = quaternions[i].inverse();
+
+					if (location.locationFlags & XR_SPACE_LOCATION_POSITION_VALID_BIT) {
+						confidences[i] = XRPose::XR_TRACKING_CONFIDENCE_HIGH;
+						positions[i] = Vector3(pose.position.x * ws, pose.position.y * ws, pose.position.z * ws);
+
+						// TODO get inverse of position, we'll do this later. For now we're ignoring bone positions which generally works better anyway
+					} else {
+						confidences[i] = XRPose::XR_TRACKING_CONFIDENCE_LOW;
+					}
+				}
+			}
+		}
+
+		if (confidences[XR_HAND_JOINT_PALM_EXT] != XRPose::XR_TRACKING_CONFIDENCE_NONE) {
+			// now update our skeleton
+			for (int i = 0; i < XR_HAND_JOINT_COUNT_EXT; i++) {
+				if (bones[i] != -1) {
+					int bone = bones[i];
+					int parent = skeleton->get_bone_parent(bone);
+
+					// Get our target quaternion
+					Quaternion q = quaternions[i];
+
+					// get local translation, parent should already be processed
+					if (parent == -1) {
+						// use our palm location here, that is what we are tracking
+						q = inv_quaternions[XR_HAND_JOINT_PALM_EXT] * q;
+					} else {
+						int found = false;
+						for (int b = 0; b < XR_HAND_JOINT_COUNT_EXT && !found; b++) {
+							if (bones[b] == parent) {
+								q = inv_quaternions[b] * q;
+								found = true;
+							}
+						}
+					}
+
+					// And get the movement from our rest position
+					// Transform3D rest = skeleton->get_bone_rest(bones[i]);
+					// q = rest.basis.get_quaternion().inverse() * q;
+
+					// and set our pose
+					// skeleton->set_bone_pose_position(bones[i], v);
+					skeleton->set_bone_pose_rotation(bones[i], q);
+				}
+			}
+
+			Transform3D t;
+			t.basis = Basis(quaternions[XR_HAND_JOINT_PALM_EXT]);
+			t.origin = positions[XR_HAND_JOINT_PALM_EXT];
+			set_transform(t);
+
+			// show it
+			set_visible(true);
+		} else {
+			// hide it
+			set_visible(false);
+		}
+	} else {
+		// hide it
+		set_visible(false);
+	}
+}
+
+void OpenXRHand::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			_get_bones();
+
+			set_process_internal(true);
+		} break;
+		case NOTIFICATION_EXIT_TREE: {
+			set_process_internal(false);
+
+			// reset
+			for (int i = 0; i < XR_HAND_JOINT_COUNT_EXT; i++) {
+				bones[i] = -1;
+			}
+		} break;
+		case NOTIFICATION_INTERNAL_PROCESS: {
+			_update_skeleton();
+		} break;
+		default: {
+		} break;
+	}
+}
diff --git a/modules/openxr/scene/openxr_hand.h b/modules/openxr/scene/openxr_hand.h
new file mode 100644
index 0000000000..f8499cc172
--- /dev/null
+++ b/modules/openxr/scene/openxr_hand.h
@@ -0,0 +1,93 @@
+/*************************************************************************/
+/*  openxr_hand.h                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* 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 OPENXR_HAND_H
+#define OPENXR_HAND_H
+
+#include "scene/3d/node_3d.h"
+#include "scene/3d/skeleton_3d.h"
+
+class OpenXRAPI;
+class OpenXRHandTrackingExtension;
+
+class OpenXRHand : public Node3D {
+	GDCLASS(OpenXRHand, Node3D);
+
+public:
+	enum Hands {
+		HAND_LEFT,
+		HAND_RIGHT,
+		HAND_MAX
+	};
+
+	enum MotionRange {
+		MOTION_RANGE_UNOBSTRUCTED,
+		MOTION_RANGE_CONFORM_TO_CONTROLLER,
+		MOTION_RANGE_MAX
+	};
+
+private:
+	OpenXRAPI *openxr_api = nullptr;
+	OpenXRHandTrackingExtension *hand_tracking_ext = nullptr;
+
+	Hands hand = HAND_LEFT;
+	MotionRange motion_range = MOTION_RANGE_UNOBSTRUCTED;
+	NodePath hand_skeleton;
+
+	int64_t bones[XR_HAND_JOINT_COUNT_EXT];
+
+	void _set_motion_range();
+
+	Skeleton3D *get_skeleton();
+	void _get_bones();
+	void _update_skeleton();
+
+protected:
+	static void _bind_methods();
+
+public:
+	OpenXRHand();
+
+	void set_hand(const Hands p_hand);
+	Hands get_hand() const;
+
+	void set_motion_range(const MotionRange p_motion_range);
+	MotionRange get_motion_range() const;
+
+	void set_hand_skeleton(const NodePath &p_hand_skeleton);
+	NodePath get_hand_skeleton() const;
+
+	void _notification(int p_what);
+};
+
+VARIANT_ENUM_CAST(OpenXRHand::Hands)
+VARIANT_ENUM_CAST(OpenXRHand::MotionRange)
+
+#endif // OPENXR_HAND_H