Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-03 20:50:07 +01:00
Code Issues Projects Releases Packages Wiki Activity

Add some math verifying relationship between get_viewer_pose and get_pose

Browse source
This commit is contained in:
Manish Goregaokar 2019-04-05 18:42:57 -07:00
parent 91378cc859
commit ea3609b42e
2 changed files with 28 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

10
components/script/dom/xrreferencespace.rs
View file

@ -56,12 +56,18 @@ impl XRReferenceSpaceMethods for XRReferenceSpace {
impl XRReferenceSpace { impl XRReferenceSpace {
/// Gets pose of the viewer with respect to this space /// Gets pose of the viewer with respect to this space
/// ///
/// This is equivalent to `get_pose(self).inverse() * get_pose(viewerSpace)`, however /// This is equivalent to `get_pose(self).inverse() * get_pose(viewerSpace)` (in column vector notation),
/// we specialize it to be efficient /// however we specialize it to be efficient
pub fn get_viewer_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> { pub fn get_viewer_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
let pose = self.get_unoffset_viewer_pose(base_pose); let pose = self.get_unoffset_viewer_pose(base_pose);
// This may change, see https://github.com/immersive-web/webxr/issues/567 // This may change, see https://github.com/immersive-web/webxr/issues/567
// in column-vector notation,
// get_viewer_pose(space) = get_pose(space).inverse() * get_pose(viewer_space)
// = (get_unoffset_pose(space) * offset).inverse() * get_pose(viewer_space)
// = offset.inverse() * get_unoffset_pose(space).inverse() * get_pose(viewer_space)
// = offset.inverse() * get_unoffset_viewer_pose(space)
let offset = self.transform.get().transform(); let offset = self.transform.get().transform();
let inverse = offset.inverse(); let inverse = offset.inverse();
inverse.pre_mul(&pose) inverse.pre_mul(&pose)

24
components/script/dom/xrstationaryreferencespace.rs
View file

@ -56,25 +56,41 @@ impl XRStationaryReferenceSpace {
/// Does not apply originOffset, use get_viewer_pose on XRReferenceSpace instead /// Does not apply originOffset, use get_viewer_pose on XRReferenceSpace instead
pub fn get_unoffset_viewer_pose(&self, viewer_pose: &WebVRFrameData) -> RigidTransform3D<f64> { pub fn get_unoffset_viewer_pose(&self, viewer_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
let viewer_pose = XRSpace::viewer_pose_from_frame_data(viewer_pose); let viewer_pose = XRSpace::viewer_pose_from_frame_data(viewer_pose);
// all math is in column-vector notation
// we use the following equation to verify correctness here:
// get_viewer_pose(space) = get_pose(space).inverse() * get_pose(viewer_space)
match self.ty { match self.ty {
XRStationaryReferenceSpaceSubtype::Eye_level => { XRStationaryReferenceSpaceSubtype::Eye_level => {
// get_viewer_pose(eye_level) = get_pose(eye_level).inverse() * get_pose(viewer_space)
// = I * viewer_pose
// = viewer_pose
// we get viewer poses in eye-level space by default // we get viewer poses in eye-level space by default
viewer_pose viewer_pose
} },
XRStationaryReferenceSpaceSubtype::Floor_level => { XRStationaryReferenceSpaceSubtype::Floor_level => {
// XXXManishearth support getting floor info from stage parameters // XXXManishearth support getting floor info from stage parameters
// get_viewer_pose(floor_level) = get_pose(floor_level).inverse() * get_pose(viewer_space)
// = Translate(-2).inverse() * viewer_pose
// = Translate(2) * viewer_pose
// assume approximate user height of 2 meters // assume approximate user height of 2 meters
let floor_to_eye: RigidTransform3D<f64> = Vector3D::new(0., 2., 0.).into(); let floor_to_eye: RigidTransform3D<f64> = Vector3D::new(0., 2., 0.).into();
floor_to_eye.pre_mul(&viewer_pose) floor_to_eye.pre_mul(&viewer_pose)
} },
XRStationaryReferenceSpaceSubtype::Position_disabled => { XRStationaryReferenceSpaceSubtype::Position_disabled => {
// get_viewer_pose(pos_disabled) = get_pose(pos_disabled).inverse() * get_pose(viewer_space)
// = viewer_pose.translation.inverse() * viewer_pose
// = viewer_pose.translation.inverse() * viewer_pose.translation
// * viewer_pose.rotation
// = viewer_pose.rotation
// This space follows the user around, but does not mirror the user's orientation // This space follows the user around, but does not mirror the user's orientation
// Thus, the viewer's pose relative to this space is simply their orientation // Thus, the viewer's pose relative to this space is simply their orientation
viewer_pose.rotation.into() viewer_pose.rotation.into()
} },
} }
} }
/// Gets pose represented by this space /// Gets pose represented by this space