XR Controller Support Step 5: Navigation

Adds navigation transforms (pose, scale) to the XR session state that
will be applied to the viewer/controller poses. By manipulating these
values, a viewer can move through the VR viewport without the need to
physically walk through it.

Add-ons can access these transforms via Python
(XrSessionState.navigation_location/rotation/scale) to use with custom
operators.

Also adds 3 new VR navigation operators that will be exposed to users
as default actions in the VR Scene Inspection add-on. While all three
of these operators have custom properties that can greatly influence
their behaviors, for now these properties will not be accessible by
users from the UI. However, other add-ons can still set these custom
properties if they desire.

1). Raycast-based teleport
Moves the user to a location pointed at on a mesh object. The result
can optionally be constrained to specific axes, for example to achieve
"elevation snapping" behavior by constraining to the Z-axis. In
addition, one can specify an interpolation factor and offset.

Credit to KISKA for the elevation snapping concept.

2). "Grab" navigation
Moves the user through the viewport by pressing inputs on one or two
held controllers and applying deltas to the navigation matrix based on
the displacement of these controllers. When inputs on both controllers
are pressed at the same time (bimanual interaction), the user can scale
themselves relative to the scene based on the distance between the
controllers.

Also supports locks for location, rotation, and scale.

3). Fly navigation
Navigates the viewport by pressing a button and moving/turning relative to
navigation space or the VR viewer or controller. Via the operator's
properties, one can select from a variety of these modes as well as
specify the min/max speed and whether to lock elevation.

Reviewed By: Severin

Differential Revision: https://developer.blender.org/D11501

1 files changed, 21 insertions, 1 deletions

diff --git a/source/blender/windowmanager/xr/intern/wm_xr_intern.h b/source/blender/windowmanager/xr/intern/wm_xr_intern.h
index 2cd0ba5c056..6df70dc37aa 100644
--- a/source/blender/windowmanager/xr/intern/wm_xr_intern.h
+++ b/source/blender/windowmanager/xr/intern/wm_xr_intern.h
@@ -33,6 +33,8 @@ typedef struct wmXrSessionState {
   GHOST_XrPose viewer_pose;
   /** The last known view matrix, calculated from above's viewer pose. */
   float viewer_viewmat[4][4];
+  /** The last known viewer matrix, without navigation applied. */
+  float viewer_mat_base[4][4];
   float focal_len;
 
   /** Copy of XrSessionSettings.base_pose_ data to detect changes that need
@@ -43,6 +45,8 @@ typedef struct wmXrSessionState {
   int prev_settings_flag;
   /** Copy of wmXrDrawData.base_pose. */
   GHOST_XrPose prev_base_pose;
+  /** Copy of wmXrDrawData.base_scale. */
+  float prev_base_scale;
   /** Copy of GHOST_XrDrawViewInfo.local_pose. */
   GHOST_XrPose prev_local_pose;
   /** Copy of wmXrDrawData.eye_position_ofs. */
@@ -51,6 +55,15 @@ typedef struct wmXrSessionState {
   bool force_reset_to_base_pose;
   bool is_view_data_set;
 
+  /** Current navigation transforms. */
+  GHOST_XrPose nav_pose;
+  float nav_scale;
+  /** Navigation transforms from the last actions sync, used to calculate the viewer/controller
+   * poses. */
+  GHOST_XrPose nav_pose_prev;
+  float nav_scale_prev;
+  bool is_navigation_dirty;
+
   /** Last known controller data. */
   ListBase controllers; /* #wmXrController */
 
@@ -106,6 +119,8 @@ typedef struct wmXrDrawData {
    * space). With positional tracking enabled, it should be the same as the base pose, when
    * disabled it also contains a location delta from the moment the option was toggled. */
   GHOST_XrPose base_pose;
+  /** Base scale (uniform, world space). */
+  float base_scale;
   /** Offset to _substract_ from the OpenXR eye and viewer pose to get the wanted effective pose
    * (e.g. a pose exactly at the landmark position). */
   float eye_position_ofs[3]; /* Local/view space. */
@@ -123,9 +138,11 @@ typedef struct wmXrController {
   /** Pose (in world space) that represents the user's hand when holding the controller. */
   GHOST_XrPose grip_pose;
   float grip_mat[4][4];
+  float grip_mat_base[4][4];
   /** Pose (in world space) that represents the controller's aiming source. */
   GHOST_XrPose aim_pose;
   float aim_mat[4][4];
+  float aim_mat_base[4][4];
 
   /** Controller model. */
   struct GPUBatch *model;
@@ -192,13 +209,14 @@ void wm_xr_runtime_data_free(wmXrRuntimeData **runtime);
 void wm_xr_session_data_free(wmXrSessionState *state);
 wmWindow *wm_xr_session_root_window_or_fallback_get(const wmWindowManager *wm,
                                                     const wmXrRuntimeData *runtime_data);
-void wm_xr_session_draw_data_update(const wmXrSessionState *state,
+void wm_xr_session_draw_data_update(wmXrSessionState *state,
                                     const XrSessionSettings *settings,
                                     const GHOST_XrDrawViewInfo *draw_view,
                                     wmXrDrawData *draw_data);
 void wm_xr_session_state_update(const XrSessionSettings *settings,
                                 const wmXrDrawData *draw_data,
                                 const GHOST_XrDrawViewInfo *draw_view,
+                                const float viewmat[4][4],
                                 wmXrSessionState *state);
 bool wm_xr_session_surface_offscreen_ensure(wmXrSurfaceData *surface_data,
                                             const GHOST_XrDrawViewInfo *draw_view);
@@ -214,6 +232,8 @@ void wm_xr_session_controller_data_clear(wmXrSessionState *state);
 
 /* wm_xr_draw.c */
 void wm_xr_pose_to_mat(const GHOST_XrPose *pose, float r_mat[4][4]);
+void wm_xr_pose_scale_to_mat(const GHOST_XrPose *pose, float scale, float r_mat[4][4]);
 void wm_xr_pose_to_imat(const GHOST_XrPose *pose, float r_imat[4][4]);
+void wm_xr_pose_scale_to_imat(const GHOST_XrPose *pose, float scale, float r_imat[4][4]);
 void wm_xr_draw_view(const GHOST_XrDrawViewInfo *draw_view, void *customdata);
 void wm_xr_draw_controllers(const struct bContext *C, struct ARegion *region, void *customdata);