XRRigidTransform
The XRRigidTransform
is a WebXR API interface that represents the 3D geometric transform described by a position and orientation.
XRRigidTransform
is used to specify transforms throughout the WebXR APIs, including:
- The offset and orientation relative to the parent reference space to use when creating a new reference space with
getOffsetReferenceSpace()
. - The
transform
of anXRView
. - The
transform
of anXRPose
. - The
XRReferenceSpaceEvent
event'stransform
property, as found in thereset
event received by anXRReferenceSpace
.
Using XRRigidTransform
in these places rather than bare arrays that provide the matrix data has an advantage. It automatically computes the inverse of the transform and even caches it making subsequent requests significantly faster.
Constructor
new XRRigidTransform()
-
Creates a new
XRRigidTransform
object which represents a transform that applies a specified position and/or orientation.
Instance properties
XRRigidTransform.position
Read only-
A
DOMPointReadOnly
specifying a 3-dimensional point, expressed in meters, describing the translation component of the transform. Thew
property is always1.0
. XRRigidTransform.orientation
Read only-
A
DOMPointReadOnly
which contains a unit quaternion describing the rotational component of the transform. As a unit quaternion, its length is always normalized to1.0
. XRRigidTransform.matrix
Read only-
Returns the transform matrix in the form of a 16-member
Float32Array
. See the section Matrix format for how the array is used to represent a matrix. XRRigidTransform.inverse
Read only-
Returns a
XRRigidTransform
which is the inverse of this transform. That is, if applied to an object that had been previously transformed by the original transform, it will undo the transform and return the original object.
Usage notes
When an XRRigidTransform
is interpreted, the orientation is always applied to the affected object before the position is applied.
Example
This code snippet creates an XRRigidTransform
to specify the offset and orientation in relation to the current reference space to use when creating a new reference space. It then requests the first animation frame callback by calling the session's requestAnimationFrame()
method.
js
xrSession.requestReferenceSpace(refSpaceType).then((refSpace) => {
xrReferenceSpace = refSpace;
xrReferenceSpace = xrReferenceSpace.getOffsetReferenceSpace(
new XRRigidTransform(viewerStartPosition, cubeOrientation)
);
animationFrameRequestID = xrSession.requestAnimationFrame(drawFrame);
});
Specifications
Specification |
---|
WebXR Device API # xrrigidtransform-interface |
Browser compatibility
BCD tables only load in the browser