Web/API/XRInputSource/gripSpace

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The read-only XRInputSource property gripSpace returns an XRSpace whose native origin tracks the pose used to render virtual objects so they appear to be held in (or part of) the user's hand. For example, if a user were holding a virtual straight rod, the native origin of this XRSpace would be located at the approximate center of mass of the user's fist.

Syntax

var xrSpace = xrInputSource.gripSpace;

Value

An XRSpace object representing the position and orientation of the input device in virtual space, suitable for rendering an image of the device into the scene. gripSpace is null if the input source is inherently untrackable. For example, only inputs whose targetRayMode is tracked-pointer provide a gripSpace.

Imagine that the controller is shaped like a straight rod, held in the user's fist. The native origin of the grip space is located at the centroid—the center of mass—of the user's fist, tracking the position of the user's hand.

[[File:../../../../../../media.prod.mdn.mozit.cloud/attachments/2020/05/21/17260/47316a6b08985e15bb56af71edcbc337/GripSpace-LeftHand-Light.svg|thumb|none|alt=The coordinate system for the left hand's grip space.|The coordinate system for the left hand's grip space.]]

[[File:../../../../../../media.prod.mdn.mozit.cloud/attachments/2020/05/21/17261/201857f6073b79442e1d025d6c08071e/GripSpace-RightHand-Light.svg|thumb|none|alt=The coordinate system for the right hand's grip space.|The coordinate system for the right hand's grip space.]]

As shown in the diagram above, the coordinate system is oriented as follows:

The x-axis is perpendicular to the palm of the user's hand, with the direction extending outward from the back of the hand being +X if the controller is in the user's right hand or -X if the controller is in the left hand.
The z-axis along the length of the rod, parallel to the user's palm and along the length of their grip. +Z is in the direction of the user's thumb, and -Z is in the opposite direction.
The y-axis is implied by the relationship between the other two axes; as is always the case, it's the cross product of the other two axes (lying 90° away from both the X and Z axes).

Examples

In tis example, taken from the frame rendering callback, the gripSpace is used to render a mesh that represents the position and orieintation of the controller in the virtual environment.

for (let source in xrSession.inputSources) {
  if (source.gripSpace) {
    let gripPose = frame.getPose(source.gripSpace, xrRefSpace);

    if (gripPose) {
      myDrawMeshUsingTransform(controllerMesh, gripPose.transform.matrix);
    }
  }
}

For each input source which has a value for gripSpace, this loop obtains the XRPose representing the position and orientation that are described by gripSpace. If a valid pose is returned, a method myDrawMeshUsingTransform() is called to draw the controller's mesh transformed using the grip pose's transform matrix.

Specifications

Specification	Status	Comment
WebXR Device APIThe definition of 'XRInputSource.gripSpace' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`gripSpace`	Chrome Full support 79	Edge Full support 79	Firefox No support No	IE No support No	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android Full support 79	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android Full support 11.2

Legend

Full support: Full support
No support: No support

XRInputSource.gripSpace by Mozilla Contributors is licensed under CC-BY-SA 2.5.