XRRigidTransform: position property
The read-only XRRigidTransform
property
position
is a DOMPointReadOnly
object which
provides the 3D point, specified in meters, describing the translation component of the
transform.
Value
A read-only DOMPointReadOnly
indicating the 3D position component of the
transform matrix. The units are meters.
Note: The w
component of the point is always 1.0.
Examples
To create a reference space which can be used to place an object at eye level (assuming eye level is 1.5 meters):
js
function onSessionStarted(xrSession) {
xrSession.addEventListener("end", onSessionEnded);
gl = initGraphics(xrSession);
const glLayer = new XRWebGLLayer(xrSession, gl);
xrSession.updateRenderState({ baseLayer: glLayer });
if (immersiveSession) {
xrSession
.requestReferenceSpace("bounded-floor")
.then((refSpace) => {
refSpaceCreated(refSpace);
})
.catch(() => {
session.requestReferenceSpace("local-floor").then(refSpaceCreated);
});
} else {
session.requestReferenceSpace("viewer").then(refSpaceCreated);
}
}
function refSpaceCreated(refSpace) {
xrReferenceSpace = immersiveSession
? refSpace
: refSpace.getOffsetReferenceSpace(new XRRigidTransform({ y: -1.5 }));
xrSession.requestAnimationFrame(onFrame);
}
After setting up the graphics context for WebXR use, this begins by looking to see if a
variable immersiveSession
is true
; if so, we first request a
bounded-floor
reference space. If that fails (probably because
bounded-floor
isn't supported), we try requesting a
local-floor
reference space.
If we're not in an immersive session, we instead request a viewer
reference space.
In all cases, once the space has been obtained, it gets passed into the
refSpaceCreated()
function. For immersive spaces, the specified space is
saved for future use. However, for inline sessions, we know we're in a space not
automatically adjusted for floor level, so we request an offset reference space to shift
the viewer's height to 1.5 meters above the presumed floor level of 0 meters. That new
reference space is used instead of the one initially received.
Finally, an animation frame request is submitted.
Specifications
Specification |
---|
WebXR Device API # dom-xrrigidtransform-position |
Browser compatibility
BCD tables only load in the browser