Merge pull request #8567 from BastiaanOlij/ar_vr_server

AR/VR base classes and position tracker support

25 files changed, 1746 insertions, 36 deletions

diff --git a/core/math/camera_matrix.cpp b/core/math/camera_matrix.cpp
index 33ad522315..a1666ccd8b 100644
--- a/core/math/camera_matrix.cpp
+++ b/core/math/camera_matrix.cpp
@@ -91,6 +91,72 @@ void CameraMatrix::set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_
 	matrix[3][3] = 0;
 }
 
+void CameraMatrix::set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_t p_z_near, real_t p_z_far, bool p_flip_fov, int p_eye, real_t p_intraocular_dist, real_t p_convergence_dist) {
+	if (p_flip_fov) {
+		p_fovy_degrees = get_fovy(p_fovy_degrees, 1.0 / p_aspect);
+	}
+
+	real_t left, right, modeltranslation, ymax, xmax, frustumshift;
+
+	ymax = p_z_near * tan(p_fovy_degrees * Math_PI / 360.0f);
+	xmax = ymax * p_aspect;
+	frustumshift = (p_intraocular_dist / 2.0) * p_z_near / p_convergence_dist;
+
+	switch (p_eye) {
+		case 1: { // left eye
+			left = -xmax + frustumshift;
+			right = xmax + frustumshift;
+			modeltranslation = p_intraocular_dist / 2.0;
+		}; break;
+		case 2: { // right eye
+			left = -xmax - frustumshift;
+			right = xmax - frustumshift;
+			modeltranslation = -p_intraocular_dist / 2.0;
+		}; break;
+		default: { // mono, should give the same result as set_perspective(p_fovy_degrees,p_aspect,p_z_near,p_z_far,p_flip_fov)
+			left = -xmax;
+			right = xmax;
+			modeltranslation = 0.0;
+		}; break;
+	};
+
+	set_frustum(left, right, -ymax, ymax, p_z_near, p_z_far);
+
+	// translate matrix by (modeltranslation, 0.0, 0.0)
+	CameraMatrix cm;
+	cm.set_identity();
+	cm.matrix[3][0] = modeltranslation;
+	*this = *this * cm;
+}
+
+void CameraMatrix::set_for_hmd(int p_eye, real_t p_aspect, real_t p_intraocular_dist, real_t p_display_width, real_t p_display_to_lens, real_t p_oversample, real_t p_z_near, real_t p_z_far) {
+	// we first calculate our base frustum on our values without taking our lens magnification into account.
+	real_t display_to_eye = 2.0 * p_display_to_lens;
+	real_t f1 = (p_intraocular_dist * 0.5) / p_display_to_lens;
+	real_t f2 = ((p_display_width - p_intraocular_dist) * 0.5) / p_display_to_lens;
+	real_t f3 = (p_display_width / 4.0) / p_display_to_lens;
+
+	// now we apply our oversample factor to increase our FOV. how much we oversample is always a balance we strike between performance and how much
+	// we're willing to sacrifice in FOV.
+	real_t add = ((f1 + f2) * (p_oversample - 1.0)) / 2.0;
+	f1 += add;
+	f2 += add;
+
+	// always apply KEEP_WIDTH aspect ratio
+	f3 *= p_aspect;
+
+	switch (p_eye) {
+		case 1: { // left eye
+			set_frustum(-f2 * p_z_near, f1 * p_z_near, -f3 * p_z_near, f3 * p_z_near, p_z_near, p_z_far);
+		}; break;
+		case 2: { // right eye
+			set_frustum(-f1 * p_z_near, f2 * p_z_near, -f3 * p_z_near, f3 * p_z_near, p_z_near, p_z_far);
+		}; break;
+		default: { // mono, does not apply here!
+		}; break;
+	};
+};
+
 void CameraMatrix::set_orthogonal(real_t p_left, real_t p_right, real_t p_bottom, real_t p_top, real_t p_znear, real_t p_zfar) {
 
 	set_identity();
@@ -243,23 +309,44 @@ bool CameraMatrix::get_endpoints(const Transform &p_transform, Vector3 *p_8point
 			-matrix[15] + matrix[13]);
 	top_plane.normalize();
 
-	Vector3 near_endpoint;
-	Vector3 far_endpoint;
+	Vector3 near_endpoint_left, near_endpoint_right;
+	Vector3 far_endpoint_left, far_endpoint_right;
 
-	bool res = near_plane.intersect_3(right_plane, top_plane, &near_endpoint);
+	bool res = near_plane.intersect_3(right_plane, top_plane, &near_endpoint_right);
 	ERR_FAIL_COND_V(!res, false);
 
-	res = far_plane.intersect_3(right_plane, top_plane, &far_endpoint);
+	res = far_plane.intersect_3(right_plane, top_plane, &far_endpoint_right);
 	ERR_FAIL_COND_V(!res, false);
 
-	p_8points[0] = p_transform.xform(Vector3(near_endpoint.x, near_endpoint.y, near_endpoint.z));
-	p_8points[1] = p_transform.xform(Vector3(near_endpoint.x, -near_endpoint.y, near_endpoint.z));
-	p_8points[2] = p_transform.xform(Vector3(-near_endpoint.x, near_endpoint.y, near_endpoint.z));
-	p_8points[3] = p_transform.xform(Vector3(-near_endpoint.x, -near_endpoint.y, near_endpoint.z));
-	p_8points[4] = p_transform.xform(Vector3(far_endpoint.x, far_endpoint.y, far_endpoint.z));
-	p_8points[5] = p_transform.xform(Vector3(far_endpoint.x, -far_endpoint.y, far_endpoint.z));
-	p_8points[6] = p_transform.xform(Vector3(-far_endpoint.x, far_endpoint.y, far_endpoint.z));
-	p_8points[7] = p_transform.xform(Vector3(-far_endpoint.x, -far_endpoint.y, far_endpoint.z));
+	if ((matrix[8] == 0) && (matrix[9] == 0)) {
+		near_endpoint_left = near_endpoint_right;
+		near_endpoint_left.x = -near_endpoint_left.x;
+
+		far_endpoint_left = far_endpoint_right;
+		far_endpoint_left.x = -far_endpoint_left.x;
+	} else {
+		///////--- Left Plane ---///////
+		Plane left_plane = Plane(matrix[0] + matrix[3],
+				matrix[4] + matrix[7],
+				matrix[8] + matrix[11],
+				-matrix[15] - matrix[12]);
+		left_plane.normalize();
+
+		res = near_plane.intersect_3(left_plane, top_plane, &near_endpoint_left);
+		ERR_FAIL_COND_V(!res, false);
+
+		res = far_plane.intersect_3(left_plane, top_plane, &far_endpoint_left);
+		ERR_FAIL_COND_V(!res, false);
+	}
+
+	p_8points[0] = p_transform.xform(Vector3(near_endpoint_right.x, near_endpoint_right.y, near_endpoint_right.z));
+	p_8points[1] = p_transform.xform(Vector3(near_endpoint_right.x, -near_endpoint_right.y, near_endpoint_right.z));
+	p_8points[2] = p_transform.xform(Vector3(near_endpoint_left.x, near_endpoint_left.y, near_endpoint_left.z));
+	p_8points[3] = p_transform.xform(Vector3(near_endpoint_left.x, -near_endpoint_left.y, near_endpoint_left.z));
+	p_8points[4] = p_transform.xform(Vector3(far_endpoint_right.x, far_endpoint_right.y, far_endpoint_right.z));
+	p_8points[5] = p_transform.xform(Vector3(far_endpoint_right.x, -far_endpoint_right.y, far_endpoint_right.z));
+	p_8points[6] = p_transform.xform(Vector3(far_endpoint_left.x, far_endpoint_left.y, far_endpoint_left.z));
+	p_8points[7] = p_transform.xform(Vector3(far_endpoint_left.x, -far_endpoint_left.y, far_endpoint_left.z));
 
 	return true;
 }
@@ -546,7 +633,18 @@ real_t CameraMatrix::get_fov() const {
 			-matrix[15] + matrix[12]);
 	right_plane.normalize();
 
-	return Math::rad2deg(Math::acos(Math::abs(right_plane.normal.x))) * 2.0;
+	if ((matrix[8] == 0) && (matrix[9] == 0)) {
+		return Math::rad2deg(Math::acos(Math::abs(right_plane.normal.x))) * 2.0;
+	} else {
+		// our frustum is asymetrical need to calculate the left planes angle seperately..
+		Plane left_plane = Plane(matrix[3] + matrix[0],
+				matrix[7] + matrix[4],
+				matrix[11] + matrix[8],
+				matrix[15] + matrix[12]);
+		left_plane.normalize();
+
+		return Math::rad2deg(Math::acos(Math::abs(left_plane.normal.x))) + Math::rad2deg(Math::acos(Math::abs(right_plane.normal.x)));
+	}
 }
 
 void CameraMatrix::make_scale(const Vector3 &p_scale) {
diff --git a/core/math/camera_matrix.h b/core/math/camera_matrix.h
index af61e35993..4be8ffab8c 100644
--- a/core/math/camera_matrix.h
+++ b/core/math/camera_matrix.h
@@ -54,6 +54,8 @@ struct CameraMatrix {
 	void set_light_bias();
 	void set_light_atlas_rect(const Rect2 &p_rect);
 	void set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_t p_z_near, real_t p_z_far, bool p_flip_fov = false);
+	void set_perspective(real_t p_fovy_degrees, real_t p_aspect, real_t p_z_near, real_t p_z_far, bool p_flip_fov, int p_eye, real_t p_intraocular_dist, real_t p_convergence_dist);
+	void set_for_hmd(int p_eye, real_t p_aspect, real_t p_intraocular_dist, real_t p_display_width, real_t p_display_to_lens, real_t p_oversample, real_t p_z_near, real_t p_z_far);
 	void set_orthogonal(real_t p_left, real_t p_right, real_t p_bottom, real_t p_top, real_t p_znear, real_t p_zfar);
 	void set_orthogonal(real_t p_size, real_t p_aspect, real_t p_znear, real_t p_zfar, bool p_flip_fov = false);
 	void set_frustum(real_t p_left, real_t p_right, real_t p_bottom, real_t p_top, real_t p_near, real_t p_far);
diff --git a/scene/3d/arvr_nodes.cpp b/scene/3d/arvr_nodes.cpp
new file mode 100644
index 0000000000..5f2a720748
--- /dev/null
+++ b/scene/3d/arvr_nodes.cpp
@@ -0,0 +1,313 @@
+/*************************************************************************/
+/*  arvr_nodes.cpp                                                       */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 "arvr_nodes.h"
+#include "core/os/input.h"
+#include "servers/arvr/arvr_interface.h"
+#include "servers/arvr/arvr_positional_tracker.h"
+#include "servers/arvr_server.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void ARVRCamera::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			// need to find our ARVROrigin parent and let it know we're it's camera!
+			ARVROrigin *origin = get_parent()->cast_to<ARVROrigin>();
+			if (origin != NULL) {
+				origin->set_tracked_camera(this);
+			}
+		}; break;
+		case NOTIFICATION_EXIT_TREE: {
+			// need to find our ARVROrigin parent and let it know we're no longer it's camera!
+			ARVROrigin *origin = get_parent()->cast_to<ARVROrigin>();
+			if (origin != NULL) {
+				origin->clear_tracked_camera_if(this);
+			}
+		}; break;
+	};
+};
+
+String ARVRCamera::get_configuration_warning() const {
+	if (!is_visible() || !is_inside_tree())
+		return String();
+
+	// must be child node of ARVROrigin!
+	ARVROrigin *origin = get_parent()->cast_to<ARVROrigin>();
+	if (origin == NULL) {
+		return TTR("ARVRCamera must have an ARVROrigin node as its parent");
+	};
+
+	return String();
+};
+
+ARVRCamera::ARVRCamera(){
+	// nothing to do here yet for now..
+};
+
+ARVRCamera::~ARVRCamera(){
+	// nothing to do here yet for now..
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+void ARVRController::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			set_process_internal(true);
+		}; break;
+		case NOTIFICATION_EXIT_TREE: {
+			set_process_internal(false);
+		}; break;
+		case NOTIFICATION_INTERNAL_PROCESS: {
+			// get our ARVRServer
+			ARVRServer *arvr_server = ARVRServer::get_singleton();
+			ERR_FAIL_NULL(arvr_server);
+
+			// find the tracker for our controller
+			ARVRPositionalTracker *tracker = arvr_server->find_by_type_and_id(ARVRServer::TRACKER_CONTROLLER, controller_id);
+			if (tracker == NULL) {
+				// this controller is currently turned off
+				is_active = false;
+				button_states = 0;
+			} else {
+				set_transform(tracker->get_transform(true));
+
+				int joy_id = tracker->get_joy_id();
+				if (joy_id >= 0) {
+					int mask = 1;
+					// check button states
+					for (int i = 0; i < 16; i++) {
+						bool was_pressed = (button_states && mask) == mask;
+						bool is_pressed = Input::get_singleton()->is_joy_button_pressed(joy_id, i);
+
+						if (!was_pressed && is_pressed) {
+							emit_signal("button_pressed", i);
+							button_states += mask;
+						} else if (was_pressed && !is_pressed) {
+							emit_signal("button_release", i);
+							button_states -= mask;
+						};
+
+						mask = mask << 1;
+					};
+
+				} else {
+					button_states = 0;
+				};
+			};
+		}; break;
+		default:
+			break;
+	};
+};
+
+void ARVRController::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_controller_id", "controller_id"), &ARVRController::set_controller_id);
+	ClassDB::bind_method(D_METHOD("get_controller_id"), &ARVRController::get_controller_id);
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "controller_id"), "set_controller_id", "get_controller_id");
+	ClassDB::bind_method(D_METHOD("get_controller_name"), &ARVRController::get_controller_name);
+
+	// passthroughs to information about our related joystick
+	ClassDB::bind_method(D_METHOD("get_joystick_id"), &ARVRController::get_joystick_id);
+	ClassDB::bind_method(D_METHOD("is_button_pressed", "button"), &ARVRController::is_button_pressed);
+	ClassDB::bind_method(D_METHOD("get_joystick_axis", "axis"), &ARVRController::get_joystick_axis);
+
+	ClassDB::bind_method(D_METHOD("get_is_active"), &ARVRController::get_is_active);
+
+	ADD_SIGNAL(MethodInfo("button_pressed", PropertyInfo(Variant::INT, "button")));
+	ADD_SIGNAL(MethodInfo("button_release", PropertyInfo(Variant::INT, "button")));
+};
+
+void ARVRController::set_controller_id(int p_controller_id) {
+	// we don't check any bounds here, this controller may not yet be active and just be a place holder until it is.
+	controller_id = p_controller_id;
+};
+
+int ARVRController::get_controller_id(void) const {
+	return controller_id;
+};
+
+String ARVRController::get_controller_name(void) const {
+	// get our ARVRServer
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL_V(arvr_server, String());
+
+	ARVRPositionalTracker *tracker = arvr_server->find_by_type_and_id(ARVRServer::TRACKER_CONTROLLER, controller_id);
+	if (tracker == NULL) {
+		return String("Not connected");
+	};
+
+	return tracker->get_name();
+};
+
+int ARVRController::get_joystick_id() const {
+	// get our ARVRServer
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL_V(arvr_server, 0);
+
+	ARVRPositionalTracker *tracker = arvr_server->find_by_type_and_id(ARVRServer::TRACKER_CONTROLLER, controller_id);
+	if (tracker == NULL) {
+		return 0;
+	};
+
+	return tracker->get_joy_id();
+};
+
+int ARVRController::is_button_pressed(int p_button) const {
+	int joy_id = get_joystick_id();
+	if (joy_id == 0) {
+		return false;
+	};
+
+	return Input::get_singleton()->is_joy_button_pressed(joy_id, p_button);
+};
+
+float ARVRController::get_joystick_axis(int p_axis) const {
+	int joy_id = get_joystick_id();
+	if (joy_id == 0) {
+		return 0.0;
+	};
+
+	return Input::get_singleton()->get_joy_axis(joy_id, p_axis);
+};
+
+bool ARVRController::get_is_active() const {
+	return is_active;
+};
+
+String ARVRController::get_configuration_warning() const {
+	if (!is_visible() || !is_inside_tree())
+		return String();
+
+	// must be child node of ARVROrigin!
+	ARVROrigin *origin = get_parent()->cast_to<ARVROrigin>();
+	if (origin == NULL) {
+		return TTR("ARVRController must have an ARVROrigin node as its parent");
+	};
+
+	if (controller_id == 0) {
+		return TTR("The controller id must not be 0 or this controller will not be bound to an actual controller");
+	};
+
+	return String();
+};
+
+ARVRController::ARVRController() {
+	controller_id = 0;
+	is_active = true;
+};
+
+ARVRController::~ARVRController(){
+	// nothing to do here yet for now..
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+String ARVROrigin::get_configuration_warning() const {
+	if (!is_visible() || !is_inside_tree())
+		return String();
+
+	if (tracked_camera == NULL)
+		return TTR("ARVROrigin requires an ARVRCamera child node");
+
+	return String();
+};
+
+void ARVROrigin::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_world_scale", "world_scale"), &ARVROrigin::set_world_scale);
+	ClassDB::bind_method(D_METHOD("get_world_scale"), &ARVROrigin::get_world_scale);
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "world_scale"), "set_world_scale", "get_world_scale");
+};
+
+void ARVROrigin::set_tracked_camera(ARVRCamera *p_tracked_camera) {
+	tracked_camera = p_tracked_camera;
+};
+
+void ARVROrigin::clear_tracked_camera_if(ARVRCamera *p_tracked_camera) {
+	if (tracked_camera == p_tracked_camera) {
+		tracked_camera = NULL;
+	};
+};
+
+float ARVROrigin::get_world_scale() const {
+	// get our ARVRServer
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL_V(arvr_server, 1.0);
+
+	return arvr_server->get_world_scale();
+};
+
+void ARVROrigin::set_world_scale(float p_world_scale) {
+	// get our ARVRServer
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL(arvr_server);
+
+	arvr_server->set_world_scale(p_world_scale);
+};
+
+void ARVROrigin::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_ENTER_TREE: {
+			set_process_internal(true);
+		}; break;
+		case NOTIFICATION_EXIT_TREE: {
+			set_process_internal(false);
+		}; break;
+		case NOTIFICATION_INTERNAL_PROCESS: {
+			// get our ARVRServer
+			ARVRServer *arvr_server = ARVRServer::get_singleton();
+			ERR_FAIL_NULL(arvr_server);
+
+			// set our world origin to our node transform
+			arvr_server->set_world_origin(get_global_transform());
+
+			// check if we have a primary interface
+			Ref<ARVRInterface> arvr_interface = arvr_server->get_primary_interface();
+			if (arvr_interface.is_valid() && tracked_camera != NULL) {
+				// get our positioning transform for our headset
+				Transform t = arvr_interface->get_transform_for_eye(ARVRInterface::EYE_MONO, Transform());
+
+				// now apply this to our camera
+				tracked_camera->set_transform(t);
+			};
+		}; break;
+		default:
+			break;
+	};
+};
+
+ARVROrigin::ARVROrigin() {
+	tracked_camera = NULL;
+};
+
+ARVROrigin::~ARVROrigin(){
+	// nothing to do here yet for now..
+};
diff --git a/scene/3d/arvr_nodes.h b/scene/3d/arvr_nodes.h
new file mode 100644
index 0000000000..3dab263317
--- /dev/null
+++ b/scene/3d/arvr_nodes.h
@@ -0,0 +1,126 @@
+/*************************************************************************/
+/*  arvr_nodes.h                                                         */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 ARVR_NODES_H
+#define ARVR_NODES_H
+
+#include "scene/3d/camera.h"
+#include "scene/3d/spatial.h"
+
+/**
+	@author Bastiaan Olij <mux213@gmail.com>
+**/
+
+/*
+  ARVRCamera is a subclass of camera which will register itself with its parent ARVROrigin and as a result is automatically positioned
+*/
+class ARVRCamera : public Camera {
+
+	GDCLASS(ARVRCamera, Camera);
+
+protected:
+	void _notification(int p_what);
+
+public:
+	String get_configuration_warning() const;
+
+	ARVRCamera();
+	~ARVRCamera();
+};
+
+/*
+  ARVRController is a helper node that automatically updates it's position based on tracker data.
+
+  It must be a child node of our ARVROrigin node
+*/
+
+class ARVRController : public Spatial {
+
+	GDCLASS(ARVRController, Spatial);
+
+private:
+	int controller_id;
+	bool is_active;
+	int button_states;
+
+protected:
+	void _notification(int p_what);
+	static void _bind_methods();
+
+public:
+	void set_controller_id(int p_controller_id);
+	int get_controller_id(void) const;
+	String get_controller_name(void) const;
+
+	int get_joystick_id() const;
+	int is_button_pressed(int p_button) const;
+	float get_joystick_axis(int p_axis) const;
+
+	bool get_is_active() const;
+
+	String get_configuration_warning() const;
+
+	ARVRController();
+	~ARVRController();
+};
+
+/*
+	ARVROrigin is special spatial node that acts as our origin point mapping our real world center of our tracking volume into our virtual world.
+
+	It is this point that you will move around the world as the player 'moves while standing still', i.e. the player moves through teleporting or controller inputs as opposed to physically moving.
+
+	Our camera and controllers will always be child nodes and thus place relative to this origin point.
+	This node will automatically locate any camera child nodes and update its position while our ARVRController node will handle tracked controllers.
+*/
+class ARVROrigin : public Spatial {
+
+	GDCLASS(ARVROrigin, Spatial);
+
+private:
+	ARVRCamera *tracked_camera;
+
+protected:
+	void _notification(int p_what);
+	static void _bind_methods();
+
+public:
+	String get_configuration_warning() const;
+
+	void set_tracked_camera(ARVRCamera *p_tracked_camera);
+	void clear_tracked_camera_if(ARVRCamera *p_tracked_camera);
+
+	float get_world_scale() const;
+	void set_world_scale(float p_world_scale);
+
+	ARVROrigin();
+	~ARVROrigin();
+};
+
+#endif /* ARVR_NODES_H */
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 5ce347d79b..76b281ebac 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -701,6 +701,16 @@ RID Viewport::get_viewport_rid() const {
 	return viewport;
 }
 
+void Viewport::set_use_arvr(bool p_use_arvr) {
+	arvr = p_use_arvr;
+
+	VS::get_singleton()->viewport_set_use_arvr(viewport, arvr);
+}
+
+bool Viewport::use_arvr() {
+	return arvr;
+}
+
 void Viewport::set_size(const Size2 &p_size) {
 
 	if (size == p_size.floor())
@@ -2543,6 +2553,9 @@ int Viewport::get_render_info(RenderInfo p_info) {
 
 void Viewport::_bind_methods() {
 
+	ClassDB::bind_method(D_METHOD("set_use_arvr", "use"), &Viewport::set_use_arvr);
+	ClassDB::bind_method(D_METHOD("use_arvr"), &Viewport::use_arvr);
+
 	ClassDB::bind_method(D_METHOD("set_size", "size"), &Viewport::set_size);
 	ClassDB::bind_method(D_METHOD("get_size"), &Viewport::get_size);
 	ClassDB::bind_method(D_METHOD("set_world_2d", "world_2d:World2D"), &Viewport::set_world_2d);
@@ -2644,6 +2657,8 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_shadow_atlas_quadrant_subdiv", "quadrant", "subdiv"), &Viewport::set_shadow_atlas_quadrant_subdiv);
 	ClassDB::bind_method(D_METHOD("get_shadow_atlas_quadrant_subdiv", "quadrant"), &Viewport::get_shadow_atlas_quadrant_subdiv);
 
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "arvr"), "set_use_arvr", "use_arvr");
+
 	ADD_PROPERTY(PropertyInfo(Variant::RECT2, "size"), "set_size", "get_size");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "own_world"), "set_use_own_world", "is_using_own_world");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "world", PROPERTY_HINT_RESOURCE_TYPE, "World"), "set_world", "get_world");
@@ -2729,6 +2744,7 @@ Viewport::Viewport() {
 	parent = NULL;
 	listener = NULL;
 	camera = NULL;
+	arvr = false;
 	size_override = false;
 	size_override_stretch = false;
 	size_override_size = Size2(1, 1);
diff --git a/scene/main/viewport.h b/scene/main/viewport.h
index bd9747d878..83c989db54 100644
--- a/scene/main/viewport.h
+++ b/scene/main/viewport.h
@@ -148,6 +148,8 @@ private:
 	Listener *listener;
 	Set<Listener *> listeners;
 
+	bool arvr;
+
 	Camera *camera;
 	Set<Camera *> cameras;
 
@@ -349,6 +351,9 @@ public:
 	Listener *get_listener() const;
 	Camera *get_camera() const;
 
+	void set_use_arvr(bool p_use_arvr);
+	bool use_arvr();
+
 	void set_as_audio_listener(bool p_enable);
 	bool is_audio_listener() const;
 
diff --git a/scene/register_scene_types.cpp b/scene/register_scene_types.cpp
index afd4d793b9..f286bfb81a 100644
--- a/scene/register_scene_types.cpp
+++ b/scene/register_scene_types.cpp
@@ -199,6 +199,8 @@
 #include "scene/3d/camera.h"
 #include "scene/3d/listener.h"
 
+#include "scene/3d/arvr_nodes.h"
+
 #include "scene/3d/gi_probe.h"
 #include "scene/3d/interpolated_camera.h"
 #include "scene/3d/light.h"
@@ -405,6 +407,9 @@ void register_scene_types() {
 	ClassDB::register_virtual_class<VisualInstance>();
 	ClassDB::register_class<Camera>();
 	ClassDB::register_class<Listener>();
+	ClassDB::register_class<ARVRCamera>();
+	ClassDB::register_class<ARVRController>();
+	ClassDB::register_class<ARVROrigin>();
 	ClassDB::register_class<InterpolatedCamera>();
 	ClassDB::register_class<MeshInstance>();
 	ClassDB::register_class<ImmediateGeometry>();
diff --git a/servers/SCsub b/servers/SCsub
index df2daf7223..df55010a36 100644
--- a/servers/SCsub
+++ b/servers/SCsub
@@ -7,6 +7,7 @@ env.add_source_files(env.servers_sources, "*.cpp")
 
 Export('env')
 
+SConscript('arvr/SCsub')
 SConscript('physics/SCsub')
 SConscript('physics_2d/SCsub')
 SConscript('visual/SCsub')
diff --git a/servers/arvr/SCsub b/servers/arvr/SCsub
new file mode 100644
index 0000000000..ccc76e823f
--- /dev/null
+++ b/servers/arvr/SCsub
@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+
+Import('env')
+
+env.add_source_files(env.servers_sources, "*.cpp")
+
+Export('env')
diff --git a/servers/arvr/arvr_interface.cpp b/servers/arvr/arvr_interface.cpp
new file mode 100644
index 0000000000..81eb011932
--- /dev/null
+++ b/servers/arvr/arvr_interface.cpp
@@ -0,0 +1,82 @@
+/*************************************************************************/
+/*  arvr_interface.cpp                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 "arvr_interface.h"
+
+void ARVRInterface::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("get_name"), &ARVRInterface::get_name);
+
+	ClassDB::bind_method(D_METHOD("is_primary"), &ARVRInterface::is_primary);
+	ClassDB::bind_method(D_METHOD("set_is_primary", "enable"), &ARVRInterface::set_is_primary);
+
+	ClassDB::bind_method(D_METHOD("is_installed"), &ARVRInterface::is_installed);
+	ClassDB::bind_method(D_METHOD("hmd_is_present"), &ARVRInterface::hmd_is_present);
+	ClassDB::bind_method(D_METHOD("supports_hmd"), &ARVRInterface::supports_hmd);
+	ClassDB::bind_method(D_METHOD("is_initialized"), &ARVRInterface::is_initialized);
+	ClassDB::bind_method(D_METHOD("initialize"), &ARVRInterface::initialize);
+	ClassDB::bind_method(D_METHOD("uninitialize"), &ARVRInterface::uninitialize);
+
+	ClassDB::bind_method(D_METHOD("get_recommended_render_targetsize"), &ARVRInterface::get_recommended_render_targetsize);
+
+	//	These are now purely used internally, we may expose them again if we expose CameraMatrix through Variant but reduz is not a fan for good reasons :)
+	//	ClassDB::bind_method(D_METHOD("get_transform_for_eye", "eye", "cam_transform"), &ARVRInterface::get_transform_for_eye);
+	//	ClassDB::bind_method(D_METHOD("get_projection_for_eye", "eye"), &ARVRInterface::get_projection_for_eye);
+	//	ClassDB::bind_method(D_METHOD("commit_for_eye", "node:viewport"), &ARVRInterface::commit_for_eye);
+
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "primary"), "set_is_primary", "is_primary");
+
+	BIND_CONSTANT(EYE_MONO);
+	BIND_CONSTANT(EYE_LEFT);
+	BIND_CONSTANT(EYE_RIGHT);
+};
+
+StringName ARVRInterface::get_name() const {
+	return "Unknown";
+};
+
+bool ARVRInterface::is_primary() {
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL_V(arvr_server, false);
+
+	return arvr_server->get_primary_interface() == this;
+};
+
+void ARVRInterface::set_is_primary(bool p_is_primary) {
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	ERR_FAIL_NULL(arvr_server);
+
+	if (p_is_primary) {
+		ERR_FAIL_COND(!is_initialized());
+		ERR_FAIL_COND(!supports_hmd());
+
+		arvr_server->set_primary_interface(this);
+	} else {
+		arvr_server->clear_primary_interface_if(this);
+	};
+};
diff --git a/servers/arvr/arvr_interface.h b/servers/arvr/arvr_interface.h
new file mode 100644
index 0000000000..e405499fbb
--- /dev/null
+++ b/servers/arvr/arvr_interface.h
@@ -0,0 +1,89 @@
+/*************************************************************************/
+/*  arvr_interface.h                                                     */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 ARVR_INTERFACE_H
+#define ARVR_INTERFACE_H
+
+#include "core/math/camera_matrix.h"
+#include "os/thread_safe.h"
+#include "scene/main/viewport.h"
+#include "servers/arvr_server.h"
+
+/**
+	@author Bastiaan Olij <mux213@gmail.com>
+
+	The ARVR interface is a template class ontop of which we build interface to differt AR, VR and tracking SDKs.
+	The idea is that we subclass this class, implement the logic, and then instantiate a singleton of each interface
+	when Godot starts. These instances do not initialize themselves but register themselves with the AR/VR server.
+
+	If the user wants to enable AR/VR the choose the interface they want to use and initialize it.
+
+	Note that we may make this into a fully instantiable class for GDNative support.
+*/
+
+class ARVRInterface : public Reference {
+	GDCLASS(ARVRInterface, Reference);
+
+protected:
+	_THREAD_SAFE_CLASS_
+
+	static void _bind_methods();
+
+public:
+	enum Eyes {
+		EYE_MONO, /* my son says we should call this EYE_CYCLOPS */
+		EYE_LEFT,
+		EYE_RIGHT
+	};
+
+	virtual StringName get_name() const;
+
+	bool is_primary();
+	void set_is_primary(bool p_is_primary);
+
+	virtual bool is_installed() = 0; /* returns true if the middle ware related to this interface has been installed */
+	virtual bool hmd_is_present() = 0; /* returns true if our HMD is connected */
+	virtual bool supports_hmd() = 0; /* returns true is this interface handles output to an HMD or only handles positioning */
+
+	virtual bool is_initialized() = 0; /* returns true if we've initialized this interface */
+	virtual bool initialize() = 0; /* initialize this interface, if this has an HMD it becomes the primary interface */
+	virtual void uninitialize() = 0; /* deinitialize this interface */
+
+	virtual Size2 get_recommended_render_targetsize() = 0; /* returns the recommended render target size per eye for this device */
+	virtual bool is_stereo() = 0; /* returns true if this interface requires stereo rendering (for VR HMDs) or mono rendering (for mobile AR) */
+	virtual Transform get_transform_for_eye(ARVRInterface::Eyes p_eye, const Transform &p_cam_transform) = 0; /* get each eyes camera transform, also implement EYE_MONO */
+	virtual CameraMatrix get_projection_for_eye(ARVRInterface::Eyes p_eye, real_t p_aspect, real_t p_z_near, real_t p_z_far) = 0; /* get each eyes projection matrix */
+	virtual void commit_for_eye(ARVRInterface::Eyes p_eye, RID p_render_target, const Rect2 &p_screen_rect) = 0; /* output the left or right eye */
+
+	virtual void process() = 0;
+};
+
+VARIANT_ENUM_CAST(ARVRInterface::Eyes);
+
+#endif
diff --git a/servers/arvr/arvr_positional_tracker.cpp b/servers/arvr/arvr_positional_tracker.cpp
new file mode 100644
index 0000000000..4215363d16
--- /dev/null
+++ b/servers/arvr/arvr_positional_tracker.cpp
@@ -0,0 +1,142 @@
+/*************************************************************************/
+/*  arvr_postional_tracker.cpp                                           */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 "arvr_positional_tracker.h"
+#include "core/os/input.h"
+
+void ARVRPositionalTracker::_bind_methods() {
+	// this class is read only from GDScript, so we only have access to getters..
+	ClassDB::bind_method(D_METHOD("get_type"), &ARVRPositionalTracker::get_type);
+	ClassDB::bind_method(D_METHOD("get_name"), &ARVRPositionalTracker::get_name);
+	ClassDB::bind_method(D_METHOD("get_joy_id"), &ARVRPositionalTracker::get_joy_id);
+	ClassDB::bind_method(D_METHOD("get_tracks_orientation"), &ARVRPositionalTracker::get_tracks_orientation);
+	ClassDB::bind_method(D_METHOD("get_orientation"), &ARVRPositionalTracker::get_orientation);
+	ClassDB::bind_method(D_METHOD("get_tracks_position"), &ARVRPositionalTracker::get_tracks_position);
+	ClassDB::bind_method(D_METHOD("get_position"), &ARVRPositionalTracker::get_position);
+	ClassDB::bind_method(D_METHOD("get_transform", "adjust_by_reference_frame"), &ARVRPositionalTracker::get_transform);
+};
+
+void ARVRPositionalTracker::set_type(ARVRServer::TrackerType p_type) {
+	if (type != p_type) {
+		type = p_type;
+
+		ARVRServer *arvr_server = ARVRServer::get_singleton();
+		ERR_FAIL_NULL(arvr_server);
+
+		// get a tracker id for our type
+		tracker_id = arvr_server->get_free_tracker_id_for_type(p_type);
+	}
+};
+
+ARVRServer::TrackerType ARVRPositionalTracker::get_type() const {
+	return type;
+};
+
+void ARVRPositionalTracker::set_name(const String p_name) {
+	name = p_name;
+};
+
+StringName ARVRPositionalTracker::get_name() const {
+	return name;
+};
+
+int ARVRPositionalTracker::get_tracker_id() const {
+	return tracker_id;
+};
+
+void ARVRPositionalTracker::set_joy_id(int p_joy_id) {
+	joy_id = p_joy_id;
+};
+
+int ARVRPositionalTracker::get_joy_id() const {
+	return joy_id;
+};
+
+bool ARVRPositionalTracker::get_tracks_orientation() const {
+	return tracks_orientation;
+};
+
+void ARVRPositionalTracker::set_orientation(const Basis &p_orientation) {
+	_THREAD_SAFE_METHOD_
+
+	tracks_orientation = true; // obviously we have this
+	orientation = p_orientation;
+};
+
+Basis ARVRPositionalTracker::get_orientation() const {
+	_THREAD_SAFE_METHOD_
+
+	return orientation;
+};
+
+bool ARVRPositionalTracker::get_tracks_position() const {
+	return tracks_position;
+};
+
+void ARVRPositionalTracker::set_position(const Vector3 &p_position) {
+	_THREAD_SAFE_METHOD_
+
+	tracks_position = true; // obviously we have this
+	position = p_position;
+};
+
+Vector3 ARVRPositionalTracker::get_position() const {
+	_THREAD_SAFE_METHOD_
+
+	return position;
+};
+
+Transform ARVRPositionalTracker::get_transform(bool p_adjust_by_reference_frame) const {
+	Transform new_transform;
+
+	new_transform.basis = get_orientation();
+	new_transform.origin = get_position();
+
+	if (p_adjust_by_reference_frame) {
+		ARVRServer *arvr_server = ARVRServer::get_singleton();
+		ERR_FAIL_NULL_V(arvr_server, new_transform);
+
+		new_transform = arvr_server->get_reference_frame() * new_transform;
+	};
+
+	return new_transform;
+};
+
+ARVRPositionalTracker::ARVRPositionalTracker() {
+	type = ARVRServer::TRACKER_UNKNOWN;
+	name = "Unknown";
+	joy_id = -1;
+	tracker_id = 0;
+	tracks_orientation = false;
+	tracks_position = false;
+};
+
+ARVRPositionalTracker::~ARVRPositionalTracker(){
+
+};
diff --git a/servers/arvr/arvr_positional_tracker.h b/servers/arvr/arvr_positional_tracker.h
new file mode 100644
index 0000000000..e8c613b29d
--- /dev/null
+++ b/servers/arvr/arvr_positional_tracker.h
@@ -0,0 +1,85 @@
+/*************************************************************************/
+/*  arvr_positional_tracker.h                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 ARVR_POSITIONAL_TRACKER_H
+#define ARVR_POSITIONAL_TRACKER_H
+
+#include "os/thread_safe.h"
+#include "servers/arvr_server.h"
+
+/**
+	@author Bastiaan Olij <mux213@gmail.com>
+
+	The positional tracker object as an object that represents the position and orientation of a tracked object like a controller or headset.
+	An AR/VR Interface will registered the trackers it manages with our AR/VR server and update its position and orientation.
+	This is where potentially additional AR/VR interfaces may be active as there are AR/VR SDKs that solely deal with positional tracking.
+
+	@TODO:
+	- create subclass of spatial node that uses one of our positional trackers to automatically determine its position
+*/
+
+class ARVRPositionalTracker : public Object {
+	GDCLASS(ARVRPositionalTracker, Object);
+	_THREAD_SAFE_CLASS_
+
+private:
+	ARVRServer::TrackerType type; // type of tracker
+	StringName name; // (unique) name of the tracker
+	int tracker_id; // tracker index id that is unique per type
+	int joy_id; // if we also have a related joystick entity, the id of the joystick
+	bool tracks_orientation; // do we track orientation?
+	Basis orientation; // our orientation
+	bool tracks_position; // do we track position?
+	Vector3 position; // our position
+
+protected:
+	static void _bind_methods();
+
+public:
+	void set_type(ARVRServer::TrackerType p_type);
+	ARVRServer::TrackerType get_type() const;
+	void set_name(const String p_name);
+	StringName get_name() const;
+	int get_tracker_id() const;
+	void set_joy_id(int p_joy_id);
+	int get_joy_id() const;
+	bool get_tracks_orientation() const;
+	void set_orientation(const Basis &p_orientation);
+	Basis get_orientation() const;
+	bool get_tracks_position() const;
+	void set_position(const Vector3 &p_position);
+	Vector3 get_position() const;
+
+	Transform get_transform(bool p_adjust_by_reference_frame) const;
+
+	ARVRPositionalTracker();
+	~ARVRPositionalTracker();
+};
+
+#endif
diff --git a/servers/arvr/arvr_script_interface.cpp b/servers/arvr/arvr_script_interface.cpp
new file mode 100644
index 0000000000..16e607920e
--- /dev/null
+++ b/servers/arvr/arvr_script_interface.cpp
@@ -0,0 +1,127 @@
+#include "arvr_script_interface.h"
+
+ARVRScriptInterface::ARVRScriptInterface() {
+	// testing
+	printf("Construct script interface");
+}
+
+ARVRScriptInterface::~ARVRScriptInterface() {
+	if (is_initialized()) {
+		uninitialize();
+	};
+
+	// testing
+	printf("Destruct script interface");
+}
+
+StringName ARVRScriptInterface::get_name() const {
+	if (get_script_instance() && get_script_instance()->has_method("get_name")) {
+		return get_script_instance()->call("get_name");
+	} else {
+		// just return something for now
+		return "ARVR Script interface";
+	}
+}
+
+bool ARVRScriptInterface::is_installed() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("is_installed")), false);
+	return get_script_instance()->call("is_installed");
+}
+
+bool ARVRScriptInterface::hmd_is_present() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("hmd_is_present")), false);
+	return get_script_instance()->call("hmd_is_present");
+}
+
+bool ARVRScriptInterface::supports_hmd() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("supports_hmd")), false);
+	return get_script_instance()->call("supports_hmd");
+}
+
+bool ARVRScriptInterface::is_stereo() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("is_stereo")), false);
+	return get_script_instance()->call("is_stereo");
+}
+
+bool ARVRScriptInterface::is_initialized() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("is_initialized")), false);
+	return get_script_instance()->call("is_initialized");
+}
+
+bool ARVRScriptInterface::initialize() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("initialize")), false);
+	return get_script_instance()->call("initialize");
+}
+
+void ARVRScriptInterface::uninitialize() {
+	ARVRServer *arvr_server = ARVRServer::get_singleton();
+	if (arvr_server != NULL) {
+		// Whatever happens, make sure this is no longer our primary interface
+		arvr_server->clear_primary_interface_if(this);
+	}
+
+	ERR_FAIL_COND(!(get_script_instance() && get_script_instance()->has_method("uninitialize")));
+	get_script_instance()->call("uninitialize");
+}
+
+Size2 ARVRScriptInterface::get_recommended_render_targetsize() {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("get_recommended_render_targetsize")), Size2());
+	return get_script_instance()->call("get_recommended_render_targetsize");
+}
+
+Transform ARVRScriptInterface::get_transform_for_eye(Eyes p_eye, const Transform &p_cam_transform) {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("get_transform_for_eye")), Transform());
+	return get_script_instance()->call("get_transform_for_eye", p_eye, p_cam_transform);
+}
+
+// Suggestion from Reduz, as we can't return a CameraMatrix, return a PoolVector with our 16 floats
+PoolVector<float> ARVRScriptInterface::_get_projection_for_eye(Eyes p_eye, real_t p_aspect, real_t p_z_near, real_t p_z_far) {
+	ERR_FAIL_COND_V(!(get_script_instance() && get_script_instance()->has_method("_get_projection_for_eye")), PoolVector<float>());
+	return get_script_instance()->call("_get_projection_for_eye", p_eye, p_aspect, p_z_near, p_z_far);
+}
+
+CameraMatrix ARVRScriptInterface::get_projection_for_eye(Eyes p_eye, real_t p_aspect, real_t p_z_near, real_t p_z_far) {
+	CameraMatrix cm;
+	int i = 0;
+	int j = 0;
+
+	PoolVector<float> cm_as_floats = _get_projection_for_eye(p_eye, p_aspect, p_z_near, p_z_far);
+
+	for (int k = 0; k < cm_as_floats.size() && i < 4; k++) {
+		cm.matrix[i][j] = cm_as_floats[k];
+		j++;
+		if (j == 4) {
+			j = 0;
+			i++;
+		};
+	};
+
+	return cm;
+}
+
+void ARVRScriptInterface::commit_for_eye(ARVRInterface::Eyes p_eye, RID p_render_target, const Rect2 &p_screen_rect) {
+	ERR_FAIL_COND(!(get_script_instance() && get_script_instance()->has_method("commit_for_eye")));
+	get_script_instance()->call("commit_for_eye");
+}
+
+void ARVRScriptInterface::process() {
+	ERR_FAIL_COND(!(get_script_instance() && get_script_instance()->has_method("process")));
+	get_script_instance()->call("process");
+}
+
+void ARVRScriptInterface::_bind_methods() {
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "is_installed"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "hmd_is_present"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "supports_hmd"));
+
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "is_initialized"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "initialize"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("uninitialize"));
+
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::BOOL, "is_stereo"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::VECTOR2, "get_recommended_render_targetsize"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo(Variant::TRANSFORM, "get_transform_for_eye", PropertyInfo(Variant::INT, "eye"), PropertyInfo(Variant::TRANSFORM, "cam_transform")));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("_get_projection_for_eye"));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("commit_for_eye", PropertyInfo(Variant::INT, "eye"), PropertyInfo(Variant::_RID, "render_target")));
+	ClassDB::add_virtual_method(get_class_static(), MethodInfo("process"));
+}
diff --git a/servers/arvr/arvr_script_interface.h b/servers/arvr/arvr_script_interface.h
new file mode 100644
index 0000000000..04ca33901a
--- /dev/null
+++ b/servers/arvr/arvr_script_interface.h
@@ -0,0 +1,47 @@
+#ifndef SCRIPT_INTERFACE_H
+#define SCRIPT_INTERFACE_H
+
+#include "arvr_interface.h"
+
+/**
+	@authors Hinsbart & Karroffel
+
+	This subclass of our AR/VR interface forms a bridge to GDNative.
+*/
+
+class ARVRScriptInterface : public ARVRInterface {
+	GDCLASS(ARVRScriptInterface, ARVRInterface);
+
+protected:
+	static void _bind_methods();
+
+public:
+	ARVRScriptInterface();
+	~ARVRScriptInterface();
+
+	virtual StringName get_name() const;
+
+	virtual bool is_installed();
+	virtual bool hmd_is_present();
+	virtual bool supports_hmd();
+
+	virtual bool is_initialized();
+	virtual bool initialize();
+	virtual void uninitialize();
+
+	virtual Size2 get_recommended_render_targetsize();
+	virtual bool is_stereo();
+	virtual Transform get_transform_for_eye(ARVRInterface::Eyes p_eye, const Transform &p_cam_transform);
+
+	// we expose a PoolVector<float> version of this function to GDNative
+	PoolVector<float> _get_projection_for_eye(Eyes p_eye, real_t p_aspect, real_t p_z_near, real_t p_z_far);
+
+	// and a CameraMatrix version to ARVRServer
+	virtual CameraMatrix get_projection_for_eye(ARVRInterface::Eyes p_eye, real_t p_aspect, real_t p_z_near, real_t p_z_far);
+
+	virtual void commit_for_eye(ARVRInterface::Eyes p_eye, RID p_render_target, const Rect2 &p_screen_rect);
+
+	virtual void process();
+};
+
+#endif // SCRIPT_INTERFACE_H
diff --git a/servers/arvr_server.cpp b/servers/arvr_server.cpp
new file mode 100644
index 0000000000..78b3e514e6
--- /dev/null
+++ b/servers/arvr_server.cpp
@@ -0,0 +1,313 @@
+/*************************************************************************/
+/*  arvr_server.cpp                                                      */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 "arvr_server.h"
+#include "arvr/arvr_interface.h"
+#include "arvr/arvr_positional_tracker.h"
+#include "project_settings.h"
+
+ARVRServer *ARVRServer::singleton = NULL;
+
+ARVRServer *ARVRServer::get_singleton() {
+	return singleton;
+};
+
+void ARVRServer::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("get_world_scale"), &ARVRServer::get_world_scale);
+	ClassDB::bind_method(D_METHOD("set_world_scale"), &ARVRServer::set_world_scale);
+	ClassDB::bind_method(D_METHOD("get_reference_frame"), &ARVRServer::get_reference_frame);
+	ClassDB::bind_method(D_METHOD("request_reference_frame", "ignore_tilt", "keep_height"), &ARVRServer::request_reference_frame);
+
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "world_scale"), "set_world_scale", "get_world_scale");
+
+	ClassDB::bind_method(D_METHOD("get_interface_count"), &ARVRServer::get_interface_count);
+	ClassDB::bind_method(D_METHOD("get_interface:ARVRInterface", "idx"), &ARVRServer::get_interface);
+	ClassDB::bind_method(D_METHOD("find_interface:ARVRInterface", "name"), &ARVRServer::find_interface);
+	ClassDB::bind_method(D_METHOD("get_tracker_count"), &ARVRServer::get_tracker_count);
+	ClassDB::bind_method(D_METHOD("get_tracker:ARVRPositionalTracker", "idx"), &ARVRServer::get_tracker);
+
+	ClassDB::bind_method(D_METHOD("set_primary_interface"), &ARVRServer::set_primary_interface);
+
+	ClassDB::bind_method(D_METHOD("add_interface"), &ARVRServer::add_interface);
+	ClassDB::bind_method(D_METHOD("remove_interface"), &ARVRServer::remove_interface);
+
+	BIND_CONSTANT(TRACKER_CONTROLLER);
+	BIND_CONSTANT(TRACKER_BASESTATION);
+	BIND_CONSTANT(TRACKER_ANCHOR);
+	BIND_CONSTANT(TRACKER_UNKNOWN);
+	BIND_CONSTANT(TRACKER_ANY_KNOWN);
+	BIND_CONSTANT(TRACKER_ANY);
+
+	ADD_SIGNAL(MethodInfo("interface_added", PropertyInfo(Variant::STRING, "name")));
+	ADD_SIGNAL(MethodInfo("interface_removed", PropertyInfo(Variant::STRING, "name")));
+
+	ADD_SIGNAL(MethodInfo("tracker_added", PropertyInfo(Variant::STRING, "name"), PropertyInfo(Variant::INT, "type")));
+	ADD_SIGNAL(MethodInfo("tracker_removed", PropertyInfo(Variant::STRING, "name")));
+};
+
+real_t ARVRServer::get_world_scale() const {
+	return world_scale;
+};
+
+void ARVRServer::set_world_scale(real_t p_world_scale) {
+	if (world_scale < 0.01) {
+		world_scale = 0.01;
+	} else if (world_scale > 1000.0) {
+		world_scale = 1000.0;
+	};
+
+	world_scale = p_world_scale;
+};
+
+Transform ARVRServer::get_world_origin() const {
+	return world_origin;
+};
+
+void ARVRServer::set_world_origin(const Transform p_world_origin) {
+	world_origin = p_world_origin;
+};
+
+Transform ARVRServer::get_reference_frame() const {
+	return reference_frame;
+};
+
+void ARVRServer::request_reference_frame(bool p_ignore_tilt, bool p_keep_height) {
+	if (primary_interface != NULL) {
+		// clear our current reference frame or we'll end up double adjusting it
+		reference_frame = Transform();
+
+		// requesting our EYE_MONO transform should return our current HMD position
+		Transform new_reference_frame = primary_interface->get_transform_for_eye(ARVRInterface::EYE_MONO, Transform());
+
+		// remove our tilt
+		if (p_ignore_tilt) {
+			// take the Y out of our Z
+			new_reference_frame.basis.set_axis(2, Vector3(new_reference_frame.basis.elements[0][2], 0.0, new_reference_frame.basis.elements[2][2]).normalized());
+
+			// Y is straight up
+			new_reference_frame.basis.set_axis(1, Vector3(0.0, 1.0, 0.0));
+
+			// and X is our cross reference
+			new_reference_frame.basis.set_axis(0, new_reference_frame.basis.get_axis(1).cross(new_reference_frame.basis.get_axis(2)).normalized());
+		};
+
+		// don't negate our height
+		if (p_keep_height) {
+			new_reference_frame.origin.y = 0.0;
+		};
+
+		reference_frame = new_reference_frame.inverse();
+	};
+};
+
+void ARVRServer::add_interface(const Ref<ARVRInterface> &p_interface) {
+	ERR_FAIL_COND(p_interface.is_null());
+
+	int idx = -1;
+	for (int i = 0; i < interfaces.size(); i++) {
+
+		if (interfaces[i] == p_interface) {
+			ERR_PRINT("Interface was already added");
+			return;
+		};
+	};
+
+	print_line("Registered interface " + p_interface->get_name());
+
+	interfaces.push_back(p_interface);
+	emit_signal("interface_added", p_interface->get_name());
+};
+
+void ARVRServer::remove_interface(const Ref<ARVRInterface> &p_interface) {
+	ERR_FAIL_COND(p_interface.is_null());
+
+	int idx = -1;
+	for (int i = 0; i < interfaces.size(); i++) {
+
+		if (interfaces[i] == p_interface) {
+
+			idx = i;
+			break;
+		};
+	};
+
+	ERR_FAIL_COND(idx == -1);
+
+	print_line("Removed interface" + p_interface->get_name());
+
+	emit_signal("interface_removed", p_interface->get_name());
+	interfaces.remove(idx);
+};
+
+int ARVRServer::get_interface_count() const {
+	return interfaces.size();
+};
+
+Ref<ARVRInterface> ARVRServer::get_interface(int p_index) const {
+	ERR_FAIL_INDEX_V(p_index, interfaces.size(), NULL);
+
+	return interfaces[p_index];
+};
+
+Ref<ARVRInterface> ARVRServer::find_interface(const String &p_name) const {
+	int idx = -1;
+	for (int i = 0; i < interfaces.size(); i++) {
+
+		if (interfaces[i]->get_name() == p_name) {
+
+			idx = i;
+			break;
+		};
+	};
+
+	ERR_FAIL_COND_V(idx == -1, NULL);
+
+	return interfaces[idx];
+};
+
+/*
+	A little extra info on the tracker ids, these are unique per tracker type so we get soem consistency in recognising our trackers, specifically controllers.
+
+	The first controller that is turned of will get ID 1, the second will get ID 2, etc.
+	The magic happens when one of the controllers is turned off, say controller 1 turns off, controller 2 will remain controller 2, controller 3 will remain controller 3.
+	If controller number 1 is turned on again it again gets ID 1 unless another new controller was turned on since.
+
+	The most likely scenario however is a controller that runs out of battery and another controller being used to replace it.
+	Because the controllers are often linked to physical objects, say you're holding a shield in controller 1, your left hand, and a gun in controller 2, your right hand, and controller 1 dies:
+	- using our tracker index would suddenly make the gun disappear and the shield jump into your right hand because controller 2 becomes controller 1.
+	- using this approach the shield disappears or is no longer tracked, but the gun stays firmly in your right hand because that is still controller 2, further more, if controller 1 is replaced the shield will return.
+*/
+
+bool ARVRServer::is_tracker_id_in_use_for_type(TrackerType p_tracker_type, int p_tracker_id) const {
+	for (int i = 0; i < trackers.size(); i++) {
+		if (trackers[i]->get_type() == p_tracker_type && trackers[i]->get_tracker_id() == p_tracker_id) {
+			return true;
+		};
+	};
+
+	// all good
+	return false;
+};
+
+int ARVRServer::get_free_tracker_id_for_type(TrackerType p_tracker_type) {
+	// we start checking at 1, 0 means that it's not a controller..
+	int tracker_id = 1;
+
+	while (is_tracker_id_in_use_for_type(p_tracker_type, tracker_id)) {
+		// try the next one
+		tracker_id++;
+	};
+
+	return tracker_id;
+};
+
+void ARVRServer::add_tracker(ARVRPositionalTracker *p_tracker) {
+	ERR_FAIL_NULL(p_tracker);
+
+	trackers.push_back(p_tracker);
+	emit_signal("tracker_added", p_tracker->get_name(), p_tracker->get_type());
+};
+
+void ARVRServer::remove_tracker(ARVRPositionalTracker *p_tracker) {
+	ERR_FAIL_NULL(p_tracker);
+
+	int idx = -1;
+	for (int i = 0; i < trackers.size(); i++) {
+
+		if (trackers[i] == p_tracker) {
+
+			idx = i;
+			break;
+		};
+	};
+
+	ERR_FAIL_COND(idx == -1);
+
+	emit_signal("tracker_removed", p_tracker->get_name());
+	trackers.remove(idx);
+};
+
+int ARVRServer::get_tracker_count() const {
+	return trackers.size();
+};
+
+ARVRPositionalTracker *ARVRServer::get_tracker(int p_index) const {
+	ERR_FAIL_INDEX_V(p_index, trackers.size(), NULL);
+
+	return trackers[p_index];
+};
+
+ARVRPositionalTracker *ARVRServer::find_by_type_and_id(TrackerType p_tracker_type, int p_tracker_id) const {
+	ERR_FAIL_COND_V(p_tracker_id == 0, NULL);
+
+	for (int i = 0; i < trackers.size(); i++) {
+		if (trackers[i]->get_type() == p_tracker_type && trackers[i]->get_tracker_id() == p_tracker_id) {
+			return trackers[i];
+		};
+	};
+
+	return NULL;
+};
+
+Ref<ARVRInterface> ARVRServer::get_primary_interface() const {
+	return primary_interface;
+};
+
+void ARVRServer::set_primary_interface(const Ref<ARVRInterface> &p_primary_interface) {
+	primary_interface = p_primary_interface;
+
+	print_line("Primary interface set to: " + primary_interface->get_name());
+};
+
+void ARVRServer::clear_primary_interface_if(const Ref<ARVRInterface> &p_primary_interface) {
+	if (primary_interface == p_primary_interface) {
+		print_line("Clearing primary interface");
+		primary_interface.unref();
+	};
+};
+
+ARVRServer::ARVRServer() {
+	singleton = this;
+	world_scale = 1.0;
+};
+
+ARVRServer::~ARVRServer() {
+	primary_interface.unref();
+
+	while (interfaces.size() > 0) {
+		interfaces.remove(0);
+	}
+
+	while (trackers.size() > 0) {
+		trackers.remove(0);
+	}
+
+	singleton = NULL;
+};
diff --git a/servers/arvr_server.h b/servers/arvr_server.h
new file mode 100644
index 0000000000..fd7c5470c3
--- /dev/null
+++ b/servers/arvr_server.h
@@ -0,0 +1,167 @@
+/*************************************************************************/
+/*  arvr_server.h                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                    http://www.godotengine.org                         */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 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 ARVR_SERVER_H
+#define ARVR_SERVER_H
+
+#include "os/thread_safe.h"
+#include "reference.h"
+#include "rid.h"
+#include "variant.h"
+
+class ARVRInterface;
+class ARVRPositionalTracker;
+
+/**
+	@author Bastiaan Olij <mux213@gmail.com>
+
+	The ARVR server is a singleton object that gives access to the various
+	objects and SDKs that are available on the system.
+	Because there can be multiple SDKs active this is exposed as an array
+	and our ARVR server object acts as a pass through
+	Also each positioning tracker is accessible from here.
+
+	I've added some additional info into this header file that should move
+	into the documention, I will do so when we're close to accepting this PR
+	or as a separate PR once this has been merged into the master branch.
+**/
+
+class ARVRServer : public Object {
+	GDCLASS(ARVRServer, Object);
+	_THREAD_SAFE_CLASS_
+
+public:
+	enum TrackerType {
+		TRACKER_CONTROLLER = 0x01, /* tracks a controller */
+		TRACKER_BASESTATION = 0x02, /* tracks location of a base station */
+		TRACKER_ANCHOR = 0x04, /* tracks an anchor point, used in AR to track a real live location */
+		TRACKER_UNKNOWN = 0x80, /* unknown tracker */
+
+		TRACKER_ANY_KNOWN = 0x7f, /* all except unknown */
+		TRACKER_ANY = 0xff /* used by get_connected_trackers to return all types */
+	};
+
+private:
+	Vector<Ref<ARVRInterface> > interfaces;
+	Vector<ARVRPositionalTracker *> trackers;
+
+	Ref<ARVRInterface> primary_interface; /* we'll identify one interface as primary, this will be used by our viewports */
+
+	real_t world_scale; /* scale by which we multiply our tracker positions */
+	Transform world_origin; /* our world origin point, maps a location in our virtual world to the origin point in our real world tracking volume */
+	Transform reference_frame; /* our reference frame */
+
+	bool is_tracker_id_in_use_for_type(TrackerType p_tracker_type, int p_tracker_id) const;
+
+protected:
+	static ARVRServer *singleton;
+
+	static void _bind_methods();
+
+public:
+	static ARVRServer *get_singleton();
+
+	/* 
+		World scale allows you to specify a scale factor that is applied to all positioning vectors in our VR world in essence scaling up, or scaling down the world.
+		For stereoscopic rendering specifically this is very important to give an accurate sense of scale.
+		Add controllers into the mix and an accurate mapping of real world movement to percieved virtual movement becomes very important.
+
+		Most VR platforms, and our assumption, is that 1 unit in our virtual world equates to 1 meter in the real mode.
+		This scale basically effects the unit size relationship to real world size.
+
+		I may remove access to this property in GDScript in favour of exposing it on the ARVROrigin node
+	*/
+	real_t get_world_scale() const;
+	void set_world_scale(real_t p_world_scale);
+
+	/*
+		The world maps the 0,0,0 coordinate of our real world coordinate system for our tracking volume to a location in our
+		virtual world. It is this origin point that should be moved when the player is moved through the world by controller
+		actions be it straffing, teleporting, etc. Movement of the player by moving through the physical space is always tracked
+		in relation to this point.
+
+		Note that the ARVROrigin spatial node in your scene automatically updates this property and it should be used instead of 
+		direct access to this property and it therefor is not available in GDScript
+
+		Note: this should not be used in AR and should be ignored by an AR based interface as it would throw what you're looking at in the real world
+		and in the virtual world out of sync
+	*/
+	Transform get_world_origin() const;
+	void set_world_origin(const Transform p_origin);
+
+	/*
+		Requesting a reference frame results in a matrix being calculated that ensures the HMD is positioned to 0,0,0 facing 0,0,-1 (need to verify this direction)
+		in the virtual world. 
+
+		Note: this should not be used in AR and should be ignored by an AR based interface as it would throw what you're looking at in the real world
+		and in the virtual world out of sync
+	*/
+	Transform get_reference_frame() const;
+	void request_reference_frame(bool p_ignore_tilt, bool p_keep_height);
+
+	/*
+		Interfaces are objects that 'glue' Godot to an AR or VR SDK such as the Oculus SDK, OpenVR, OpenHMD, etc. 
+	*/
+	void add_interface(const Ref<ARVRInterface> &p_interface);
+	void remove_interface(const Ref<ARVRInterface> &p_interface);
+	int get_interface_count() const;
+	Ref<ARVRInterface> get_interface(int p_index) const;
+	Ref<ARVRInterface> find_interface(const String &p_name) const;
+
+	/*
+		note, more then one interface can technically be active, especially on mobile, but only one interface is used for
+		rendering. This interface identifies itself by calling set_primary_interface when it is initialized
+	*/
+	Ref<ARVRInterface> get_primary_interface() const;
+	void set_primary_interface(const Ref<ARVRInterface> &p_primary_interface);
+	void clear_primary_interface_if(const Ref<ARVRInterface> &p_primary_interface); /* this is automatically called if an interface destructs */
+
+	/*
+		Our trackers are objects that expose the orientation and position of physical devices such as controller, anchor points, etc. 
+		They are created and managed by our active AR/VR interfaces.
+
+		Note that for trackers that 
+	*/
+	int get_free_tracker_id_for_type(TrackerType p_tracker_type);
+	void add_tracker(ARVRPositionalTracker *p_tracker);
+	void remove_tracker(ARVRPositionalTracker *p_tracker);
+	int get_tracker_count() const;
+	ARVRPositionalTracker *get_tracker(int p_index) const;
+	ARVRPositionalTracker *find_by_type_and_id(TrackerType p_tracker_type, int p_tracker_id) const;
+
+	ARVRServer();
+	~ARVRServer();
+};
+
+#define ARVR ARVRServer
+
+VARIANT_ENUM_CAST(ARVRServer::TrackerType);
+
+#endif
diff --git a/servers/register_server_types.cpp b/servers/register_server_types.cpp
index c5029d1e13..092f445c13 100644
--- a/servers/register_server_types.cpp
+++ b/servers/register_server_types.cpp
@@ -30,6 +30,10 @@
 #include "register_server_types.h"
 #include "project_settings.h"
 
+#include "arvr/arvr_interface.h"
+#include "arvr/arvr_positional_tracker.h"
+#include "arvr/arvr_script_interface.h"
+#include "arvr_server.h"
 #include "audio/audio_effect.h"
 #include "audio/audio_stream.h"
 #include "audio/effects/audio_effect_amplify.h"
@@ -70,16 +74,23 @@ static void _debugger_get_resource_usage(List<ScriptDebuggerRemote::ResourceUsag
 }
 
 ShaderTypes *shader_types = NULL;
+ARVRServer *arvr_server = NULL;
 
 void register_server_types() {
+	arvr_server = memnew(ARVRServer);
 
 	ProjectSettings::get_singleton()->add_singleton(ProjectSettings::Singleton("VisualServer", VisualServer::get_singleton()));
 	ProjectSettings::get_singleton()->add_singleton(ProjectSettings::Singleton("AudioServer", AudioServer::get_singleton()));
 	ProjectSettings::get_singleton()->add_singleton(ProjectSettings::Singleton("PhysicsServer", PhysicsServer::get_singleton()));
 	ProjectSettings::get_singleton()->add_singleton(ProjectSettings::Singleton("Physics2DServer", Physics2DServer::get_singleton()));
+	ProjectSettings::get_singleton()->add_singleton(ProjectSettings::Singleton("ARVRServer", ARVRServer::get_singleton()));
 
 	shader_types = memnew(ShaderTypes);
 
+	ClassDB::register_virtual_class<ARVRInterface>();
+	ClassDB::register_class<ARVRPositionalTracker>();
+	ClassDB::register_class<ARVRScriptInterface>();
+
 	ClassDB::register_virtual_class<AudioStream>();
 	ClassDB::register_virtual_class<AudioStreamPlayback>();
 	ClassDB::register_class<AudioStreamRandomPitch>();
@@ -133,5 +144,9 @@ void register_server_types() {
 
 void unregister_server_types() {
 
+	//@TODO move this into iPhone/Android implementation? just have this here for testing...
+	//	mobile_interface = NULL;
+
 	memdelete(shader_types);
+	memdelete(arvr_server);
 }
diff --git a/servers/visual/visual_server_raster.h b/servers/visual/visual_server_raster.h
index 58481fc3f6..b13bb904ab 100644
--- a/servers/visual/visual_server_raster.h
+++ b/servers/visual/visual_server_raster.h
@@ -908,6 +908,7 @@ public:
 
 	BIND0R(RID, viewport_create)
 
+	BIND2(viewport_set_use_arvr, RID, bool)
 	BIND3(viewport_set_size, RID, int, int)
 
 	BIND2(viewport_set_active, RID, bool)
diff --git a/servers/visual/visual_server_scene.cpp b/servers/visual/visual_server_scene.cpp
index c383be549b..87431a2ce4 100644
--- a/servers/visual/visual_server_scene.cpp
+++ b/servers/visual/visual_server_scene.cpp
@@ -1658,6 +1658,7 @@ void VisualServerScene::_light_instance_update_shadow(Instance *p_instance, cons
 }
 
 void VisualServerScene::render_camera(RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas) {
+	// render to mono camera
 
 	Camera *camera = camera_owner.getornull(p_camera);
 	ERR_FAIL_COND(!camera);
@@ -1697,6 +1698,25 @@ void VisualServerScene::render_camera(RID p_camera, RID p_scenario, Size2 p_view
 	_render_scene(camera->transform, camera_matrix, ortho, camera->env, camera->visible_layers, p_scenario, p_shadow_atlas, RID(), -1);
 }
 
+void VisualServerScene::render_camera(Ref<ARVRInterface> &p_interface, ARVRInterface::Eyes p_eye, RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas) {
+	// render for AR/VR interface
+
+	Camera *camera = camera_owner.getornull(p_camera);
+	ERR_FAIL_COND(!camera);
+
+	/* SETUP CAMERA, we are ignoring type and FOV here */
+	bool ortho = false;
+	float aspect = p_viewport_size.width / (float)p_viewport_size.height;
+	CameraMatrix camera_matrix = p_interface->get_projection_for_eye(p_eye, aspect, camera->znear, camera->zfar);
+
+	// We also ignore our camera position, it will have been positioned with a slightly old tracking position.
+	// Instead we take our origin point and have our ar/vr interface add fresh tracking data! Whoohoo!
+	Transform world_origin = ARVRServer::get_singleton()->get_world_origin();
+	Transform cam_transform = p_interface->get_transform_for_eye(p_eye, world_origin);
+
+	_render_scene(cam_transform, camera_matrix, ortho, camera->env, camera->visible_layers, p_scenario, p_shadow_atlas, RID(), -1);
+};
+
 void VisualServerScene::_render_scene(const Transform p_cam_transform, const CameraMatrix &p_cam_projection, bool p_cam_orthogonal, RID p_force_environment, uint32_t p_visible_layers, RID p_scenario, RID p_shadow_atlas, RID p_reflection_probe, int p_reflection_probe_pass) {
 
 	Scenario *scenario = scenario_owner.getornull(p_scenario);
diff --git a/servers/visual/visual_server_scene.h b/servers/visual/visual_server_scene.h
index 168dfddfd4..17b95946b3 100644
--- a/servers/visual/visual_server_scene.h
+++ b/servers/visual/visual_server_scene.h
@@ -38,6 +38,7 @@
 #include "os/semaphore.h"
 #include "os/thread.h"
 #include "self_list.h"
+#include "servers/arvr/arvr_interface.h"
 
 class VisualServerScene {
 public:
@@ -521,6 +522,7 @@ public:
 	void render_empty_scene(RID p_scenario, RID p_shadow_atlas);
 
 	void render_camera(RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas);
+	void render_camera(Ref<ARVRInterface> &p_interface, ARVRInterface::Eyes p_eye, RID p_camera, RID p_scenario, Size2 p_viewport_size, RID p_shadow_atlas);
 	void update_dirty_instances();
 
 	//probes
diff --git a/servers/visual/visual_server_viewport.cpp b/servers/visual/visual_server_viewport.cpp
index 2a37b64759..ad9dec090a 100644
--- a/servers/visual/visual_server_viewport.cpp
+++ b/servers/visual/visual_server_viewport.cpp
@@ -33,7 +33,7 @@
 #include "visual_server_global.h"
 #include "visual_server_scene.h"
 
-void VisualServerViewport::_draw_viewport(Viewport *p_viewport) {
+void VisualServerViewport::_draw_viewport(Viewport *p_viewport, ARVRInterface::Eyes p_eye) {
 
 	/* Camera should always be BEFORE any other 3D */
 
@@ -90,8 +90,13 @@ void VisualServerViewport::_draw_viewport(Viewport *p_viewport) {
 	}
 
 	if (!scenario_draw_canvas_bg && can_draw_3d) {
+		Ref<ARVRInterface> arvr_interface = ARVRServer::get_singleton()->get_primary_interface();
 
-		VSG::scene->render_camera(p_viewport->camera, p_viewport->scenario, p_viewport->size, p_viewport->shadow_atlas);
+		if (p_viewport->use_arvr && arvr_interface.is_valid()) {
+			VSG::scene->render_camera(arvr_interface, p_eye, p_viewport->camera, p_viewport->scenario, p_viewport->size, p_viewport->shadow_atlas);
+		} else {
+			VSG::scene->render_camera(p_viewport->camera, p_viewport->scenario, p_viewport->size, p_viewport->shadow_atlas);
+		}
 	}
 
 	if (!p_viewport->hide_canvas) {
@@ -260,15 +265,19 @@ void VisualServerViewport::_draw_viewport(Viewport *p_viewport) {
 }
 
 void VisualServerViewport::draw_viewports() {
-
-	//sort viewports
-
-	//draw viewports
+	// get our arvr interface in case we need it
+	Ref<ARVRInterface> arvr_interface = ARVRServer::get_singleton()->get_primary_interface();
+	if (arvr_interface.is_valid()) {
+		// update our positioning information as late as possible...
+		arvr_interface->process();
+	}
 
 	clear_color = GLOBAL_GET("rendering/environment/default_clear_color");
 
+	//sort viewports
 	active_viewports.sort_custom<ViewportSort>();
 
+	//draw viewports
 	for (int i = 0; i < active_viewports.size(); i++) {
 
 		Viewport *vp = active_viewports[i];
@@ -286,25 +295,47 @@ void VisualServerViewport::draw_viewports() {
 
 		VSG::storage->render_target_clear_used(vp->render_target);
 
-		VSG::rasterizer->set_current_render_target(vp->render_target);
+		if (vp->use_arvr && arvr_interface.is_valid()) {
+			// override our size, make sure it matches our required size
+			Size2 size = arvr_interface->get_recommended_render_targetsize();
+			VSG::storage->render_target_set_size(vp->render_target, size.x, size.y);
 
-		VSG::scene_render->set_debug_draw_mode(vp->debug_draw);
-		VSG::storage->render_info_begin_capture();
+			// render mono or left eye first
+			ARVRInterface::Eyes leftOrMono = arvr_interface->is_stereo() ? ARVRInterface::EYE_LEFT : ARVRInterface::EYE_MONO;
+			VSG::rasterizer->set_current_render_target(vp->render_target);
+			_draw_viewport(vp, leftOrMono);
+			arvr_interface->commit_for_eye(leftOrMono, vp->render_target, vp->viewport_to_screen_rect);
 
-		_draw_viewport(vp);
+			// render right eye
+			if (leftOrMono == ARVRInterface::EYE_LEFT) {
+				// commit for eye may have changed the render target
+				VSG::rasterizer->set_current_render_target(vp->render_target);
 
-		VSG::storage->render_info_end_capture();
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_OBJECTS_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_OBJECTS_IN_FRAME);
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_VERTICES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_VERTICES_IN_FRAME);
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_MATERIAL_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_MATERIAL_CHANGES_IN_FRAME);
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_SHADER_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_SHADER_CHANGES_IN_FRAME);
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_SURFACE_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_SURFACE_CHANGES_IN_FRAME);
-		vp->render_info[VS::VIEWPORT_RENDER_INFO_DRAW_CALLS_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_DRAW_CALLS_IN_FRAME);
-
-		if (vp->viewport_to_screen_rect != Rect2()) {
-			//copy to screen if set as such
-			VSG::rasterizer->set_current_render_target(RID());
-			VSG::rasterizer->blit_render_target_to_screen(vp->render_target, vp->viewport_to_screen_rect, vp->viewport_to_screen);
+				_draw_viewport(vp, ARVRInterface::EYE_RIGHT);
+				arvr_interface->commit_for_eye(ARVRInterface::EYE_RIGHT, vp->render_target, vp->viewport_to_screen_rect);
+			}
+		} else {
+			VSG::rasterizer->set_current_render_target(vp->render_target);
+
+			VSG::scene_render->set_debug_draw_mode(vp->debug_draw);
+			VSG::storage->render_info_begin_capture();
+
+			// render standard mono camera
+			_draw_viewport(vp);
+
+			VSG::storage->render_info_end_capture();
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_OBJECTS_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_OBJECTS_IN_FRAME);
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_VERTICES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_VERTICES_IN_FRAME);
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_MATERIAL_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_MATERIAL_CHANGES_IN_FRAME);
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_SHADER_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_SHADER_CHANGES_IN_FRAME);
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_SURFACE_CHANGES_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_SURFACE_CHANGES_IN_FRAME);
+			vp->render_info[VS::VIEWPORT_RENDER_INFO_DRAW_CALLS_IN_FRAME] = VSG::storage->get_captured_render_info(VS::INFO_DRAW_CALLS_IN_FRAME);
+
+			if (vp->viewport_to_screen_rect != Rect2()) {
+				//copy to screen if set as such
+				VSG::rasterizer->set_current_render_target(RID());
+				VSG::rasterizer->blit_render_target_to_screen(vp->render_target, vp->viewport_to_screen_rect, vp->viewport_to_screen);
+			}
 		}
 
 		if (vp->update_mode == VS::VIEWPORT_UPDATE_ONCE) {
@@ -329,6 +360,13 @@ RID VisualServerViewport::viewport_create() {
 	return rid;
 }
 
+void VisualServerViewport::viewport_set_use_arvr(RID p_viewport, bool p_use_arvr) {
+	Viewport *viewport = viewport_owner.getornull(p_viewport);
+	ERR_FAIL_COND(!viewport);
+
+	viewport->use_arvr = p_use_arvr;
+}
+
 void VisualServerViewport::viewport_set_size(RID p_viewport, int p_width, int p_height) {
 
 	ERR_FAIL_COND(p_width < 0 && p_height < 0);
diff --git a/servers/visual/visual_server_viewport.h b/servers/visual/visual_server_viewport.h
index f963ce4aa3..93227d1c31 100644
--- a/servers/visual/visual_server_viewport.h
+++ b/servers/visual/visual_server_viewport.h
@@ -32,6 +32,7 @@
 
 #include "rasterizer.h"
 #include "self_list.h"
+#include "servers/arvr/arvr_interface.h"
 #include "servers/visual_server.h"
 
 class VisualServerViewport {
@@ -44,6 +45,8 @@ public:
 		RID self;
 		RID parent;
 
+		bool use_arvr; /* use arvr interface to override camera positioning and projection matrices and control output */
+
 		Size2i size;
 		RID camera;
 		RID scenario;
@@ -107,6 +110,7 @@ public:
 			for (int i = 0; i < VS::VIEWPORT_RENDER_INFO_MAX; i++) {
 				render_info[i] = 0;
 			}
+			use_arvr = false;
 		}
 	};
 
@@ -131,11 +135,13 @@ public:
 
 private:
 	Color clear_color;
-	void _draw_viewport(Viewport *p_viewport);
+	void _draw_viewport(Viewport *p_viewport, ARVRInterface::Eyes p_eye = ARVRInterface::EYE_MONO);
 
 public:
 	RID viewport_create();
 
+	void viewport_set_use_arvr(RID p_viewport, bool p_use_arvr);
+
 	void viewport_set_size(RID p_viewport, int p_width, int p_height);
 
 	void viewport_attach_to_screen(RID p_viewport, const Rect2 &p_rect = Rect2(), int p_screen = 0);
diff --git a/servers/visual/visual_server_wrap_mt.h b/servers/visual/visual_server_wrap_mt.h
index 4567d87706..e6ce3f6a54 100644
--- a/servers/visual/visual_server_wrap_mt.h
+++ b/servers/visual/visual_server_wrap_mt.h
@@ -344,6 +344,8 @@ public:
 
 	FUNC0R(RID, viewport_create)
 
+	FUNC2(viewport_set_use_arvr, RID, bool)
+
 	FUNC3(viewport_set_size, RID, int, int)
 
 	FUNC2(viewport_set_active, RID, bool)
diff --git a/servers/visual_server.h b/servers/visual_server.h
index f515a7b990..5c9f4202f9 100644
--- a/servers/visual_server.h
+++ b/servers/visual_server.h
@@ -532,6 +532,7 @@ public:
 
 	virtual RID viewport_create() = 0;
 
+	virtual void viewport_set_use_arvr(RID p_viewport, bool p_use_arvr) = 0;
 	virtual void viewport_set_size(RID p_viewport, int p_width, int p_height) = 0;
 	virtual void viewport_set_active(RID p_viewport, bool p_active) = 0;
 	virtual void viewport_set_parent_viewport(RID p_viewport, RID p_parent_viewport) = 0;