Merge pull request #87745 from dsnopek/openxr-change-reference-space

OpenXR: Allow changing play area mode during active session

doc/classes/XRInterface.xml

@@ -141,6 +141,7 @@
  <param index="0" name="mode" type="int" enum="XRInterface.PlayAreaMode" />
  <description>
  Sets the active play area mode, will return [code]false[/code] if the mode can't be used with this interface.
+ [b]Note:[/b] Changing this after the interface has already been initialized can be jarring for the player, so it's recommended to recenter on the HMD with [method XRServer.center_on_hmd] (if switching to [constant XRInterface.XR_PLAY_AREA_STAGE]) or make the switch during a scene change.
  </description>
  </method>
  <method name="start_passthrough">

doc/classes/XRServer.xml

@@ -37,6 +37,12 @@
  You should call this method after a few seconds have passed. For example, when the user requests a realignment of the display holding a designated button on a controller for a short period of time, or when implementing a teleport mechanism.
  </description>
  </method>
+ <method name="clear_reference_frame" qualifiers="const">
+ <return type="Transform3D" />
+ <description>
+ Clears the reference frame that was set by previous calls to [method center_on_hmd].
+ </description>
+ </method>
  <method name="find_interface" qualifiers="const">
  <return type="XRInterface" />
  <param index="0" name="name" type="String" />

modules/openxr/openxr_api.cpp

@@ -680,71 +680,85 @@ bool OpenXRAPI::is_reference_space_supported(XrReferenceSpaceType p_reference_sp
  return false;
 }
 
-bool OpenXRAPI::setup_spaces() {
- XrResult result;
+bool OpenXRAPI::setup_play_space() {
+ ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
 
  XrPosef identityPose = {
  { 0.0, 0.0, 0.0, 1.0 },
  { 0.0, 0.0, 0.0 }
  };
 
- ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
+ XrReferenceSpaceType new_reference_space;
+ XrSpace new_play_space = XR_NULL_HANDLE;
+ bool will_emulate_local_floor = false;
 
- // create play space
- {
- emulating_local_floor = false;
+ if (is_reference_space_supported(requested_reference_space)) {
+ new_reference_space = requested_reference_space;
+ } else if (requested_reference_space == XR_REFERENCE_SPACE_TYPE_LOCAL_FLOOR_EXT && is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_STAGE)) {
+ print_verbose("OpenXR: LOCAL_FLOOR space isn't supported, emulating using STAGE and LOCAL spaces.");
 
- if (is_reference_space_supported(requested_reference_space)) {
- reference_space = requested_reference_space;
- } else if (requested_reference_space == XR_REFERENCE_SPACE_TYPE_LOCAL_FLOOR_EXT && is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_STAGE)) {
- print_verbose("OpenXR: LOCAL_FLOOR space isn't supported, emulating using STAGE and LOCAL spaces.");
+ new_reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
+ will_emulate_local_floor = true;
+ } else {
+ // Fallback on LOCAL, which all OpenXR runtimes are required to support.
+ print_verbose(String("OpenXR: ") + OpenXRUtil::get_reference_space_name(requested_reference_space) + String(" isn't supported, defaulting to LOCAL space."));
+ new_reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
+ }
 
- reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
- emulating_local_floor = true;
+ XrReferenceSpaceCreateInfo play_space_create_info = {
+ XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
+ nullptr, // next
+ new_reference_space, // referenceSpaceType
+ identityPose, // poseInReferenceSpace
+ };
 
- // We'll use the STAGE space to get the floor height, but we can't do that until
- // after xrWaitFrame(), so just set this flag for now.
- should_reset_emulated_floor_height = true;
+ XrResult result = xrCreateReferenceSpace(session, &play_space_create_info, &new_play_space);
+ if (XR_FAILED(result)) {
+ print_line("OpenXR: Failed to create play space [", get_error_string(result), "]");
+ return false;
+ }
 
- } else {
- // Fallback on LOCAL, which all OpenXR runtimes are required to support.
- print_verbose(String("OpenXR: ") + OpenXRUtil::get_reference_space_name(requested_reference_space) + String(" isn't supported, defaulting to LOCAL space."));
- reference_space = XR_REFERENCE_SPACE_TYPE_LOCAL;
- }
+ // If we've previously created a play space, clean it up first.
+ if (play_space != XR_NULL_HANDLE) {
+ xrDestroySpace(play_space);
+ }
+ play_space = new_play_space;
+ reference_space = new_reference_space;
 
-  XrReferenceSpaceCreateInfo play_space_create_info = {
-  XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
-  nullptr, // next
-  reference_space, // referenceSpaceType
-  identityPose, // poseInReferenceSpace
-  };
+ emulating_local_floor = will_emulate_local_floor;
+ if (emulating_local_floor) {
+ // We'll use the STAGE space to get the floor height, but we can't do that until
+ // after xrWaitFrame(), so just set this flag for now.
+ should_reset_emulated_floor_height = true;
+ }
 
- result = xrCreateReferenceSpace(session, &play_space_create_info, &play_space);
- if (XR_FAILED(result)) {
- print_line("OpenXR: Failed to create play space [", get_error_string(result), "]");
- return false;
- }
+ return true;
+}
+
+bool OpenXRAPI::setup_view_space() {
+ ERR_FAIL_COND_V(session == XR_NULL_HANDLE, false);
+
+ if (!is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_VIEW)) {
+ print_line("OpenXR: reference space XR_REFERENCE_SPACE_TYPE_VIEW is not supported.");
+ return false;
  }
 
- // create view space
- {
- if (!is_reference_space_supported(XR_REFERENCE_SPACE_TYPE_VIEW)) {
- print_line("OpenXR: reference space XR_REFERENCE_SPACE_TYPE_VIEW is not supported.");
- return false;
- }
+ XrPosef identityPose = {
+ { 0.0, 0.0, 0.0, 1.0 },
+ { 0.0, 0.0, 0.0 }
+ };
 
-  XrReferenceSpaceCreateInfo view_space_create_info = {
-  XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
-  nullptr, // next
-  XR_REFERENCE_SPACE_TYPE_VIEW, // referenceSpaceType
-  identityPose // poseInReferenceSpace
-  };
+ XrReferenceSpaceCreateInfo view_space_create_info = {
+ XR_TYPE_REFERENCE_SPACE_CREATE_INFO, // type
+ nullptr, // next
+ XR_REFERENCE_SPACE_TYPE_VIEW, // referenceSpaceType
+ identityPose // poseInReferenceSpace
+ };
 
- result = xrCreateReferenceSpace(session, &view_space_create_info, &view_space);
- if (XR_FAILED(result)) {
- print_line("OpenXR: Failed to create view space [", get_error_string(result), "]");
- return false;
- }
+ XrResult result = xrCreateReferenceSpace(session, &view_space_create_info, &view_space);
+ if (XR_FAILED(result)) {
+ print_line("OpenXR: Failed to create view space [", get_error_string(result), "]");
+ return false;
  }
 
  return true;
@@ -1262,10 +1276,14 @@ void OpenXRAPI::set_view_configuration(XrViewConfigurationType p_view_configurat
  view_configuration = p_view_configuration;
 }
 
-void OpenXRAPI::set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space) {
- ERR_FAIL_COND(is_initialized());
-
+bool OpenXRAPI::set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space) {
  requested_reference_space = p_requested_reference_space;
+
+ if (is_initialized()) {
+ return setup_play_space();
+ }
+
+ return true;
 }
 
 void OpenXRAPI::set_submit_depth_buffer(bool p_submit_depth_buffer) {
@@ -1466,7 +1484,12 @@ bool OpenXRAPI::initialize_session() {
  return false;
  }
 
- if (!setup_spaces()) {
+ if (!setup_play_space()) {
+ destroy_session();
+ return false;
+ }
+
+ if (!setup_view_space()) {
  destroy_session();
  return false;
  }

modules/openxr/openxr_api.h

@@ -232,7 +232,8 @@ class OpenXRAPI {
  bool create_session();
  bool load_supported_reference_spaces();
  bool is_reference_space_supported(XrReferenceSpaceType p_reference_space);
- bool setup_spaces();
+ bool setup_play_space();
+ bool setup_view_space();
  bool load_supported_swapchain_formats();
  bool is_swapchain_format_supported(int64_t p_swapchain_format);
  bool create_swapchains();
@@ -339,7 +340,7 @@ class OpenXRAPI {
  void set_view_configuration(XrViewConfigurationType p_view_configuration);
  XrViewConfigurationType get_view_configuration() const { return view_configuration; }
 
- void set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space);
+ bool set_requested_reference_space(XrReferenceSpaceType p_requested_reference_space);
  XrReferenceSpaceType get_requested_reference_space() const { return requested_reference_space; }
  XrReferenceSpaceType get_reference_space() const { return reference_space; }
 

modules/openxr/openxr_interface.cpp

@@ -711,7 +711,6 @@ XRInterface::PlayAreaMode OpenXRInterface::get_play_area_mode() const {
 }
 
 bool OpenXRInterface::set_play_area_mode(XRInterface::PlayAreaMode p_mode) {
- ERR_FAIL_COND_V_MSG(initialized, false, "Cannot change play area mode after OpenXR interface has been initialized");
  ERR_FAIL_NULL_V(openxr_api, false);
 
  XrReferenceSpaceType reference_space;
@@ -726,8 +725,15 @@ bool OpenXRInterface::set_play_area_mode(XRInterface::PlayAreaMode p_mode) {
  return false;
  }
 
- openxr_api->set_requested_reference_space(reference_space);
- return true;
+ if (openxr_api->set_requested_reference_space(reference_space)) {
+ XRServer *xr_server = XRServer::get_singleton();
+ if (xr_server) {
+ xr_server->clear_reference_frame();
+ }
+ return true;
+ }
+
+ return false;
 }
 
 PackedVector3Array OpenXRInterface::get_play_area() const {

servers/xr_server.cpp

@@ -55,6 +55,7 @@ void XRServer::_bind_methods() {
  ClassDB::bind_method(D_METHOD("get_world_origin"), &XRServer::get_world_origin);
  ClassDB::bind_method(D_METHOD("set_world_origin", "world_origin"), &XRServer::set_world_origin);
  ClassDB::bind_method(D_METHOD("get_reference_frame"), &XRServer::get_reference_frame);
+ ClassDB::bind_method(D_METHOD("clear_reference_frame"), &XRServer::get_reference_frame);
  ClassDB::bind_method(D_METHOD("center_on_hmd", "rotation_mode", "keep_height"), &XRServer::center_on_hmd);
  ClassDB::bind_method(D_METHOD("get_hmd_transform"), &XRServer::get_hmd_transform);
 
@@ -158,6 +159,10 @@ void XRServer::center_on_hmd(RotationMode p_rotation_mode, bool p_keep_height) {
  reference_frame = new_reference_frame.inverse();
 };
 
+void XRServer::clear_reference_frame() {
+ reference_frame = Transform3D();
+}
+
 Transform3D XRServer::get_hmd_transform() {
  Transform3D hmd_transform;
  if (primary_interface != nullptr) {

servers/xr_server.h

@@ -142,6 +142,7 @@ class XRServer : public Object {
  and in the virtual world out of sync
  */
  Transform3D get_reference_frame() const;
+ void clear_reference_frame();
  void center_on_hmd(RotationMode p_rotation_mode, bool p_keep_height);
 
  /*