Web/API/XRRigidTransform/inverse

The read-only inverse property of the XRRigidTransform interface returns another XRRigidTransform object which is the inverse of its owning transform. That is, you can always get the inverse of any XRRigidTransform using its inverse property, instead of having to explicitly generate it.

Syntax

let transformInverse = xrRigidTransform.inverse;

Value

An XRRigidTransform which contains the inverse of the XRRigidTransform on which it's accessed.

Applying the inverse of a transform to any object previously transformed by the parent XRRigidTransform always undoes the transformation, resulting in the object returning to its previous pose. In other words, its position and orientation both return to their prior configurations.

Examples

In this example, the model view matrix for an object is computed by taking the view matrix and multiplying it by the object's pose matrix.

let modelViewMatrix = mat4.create();

for (let view of pose.view) {
  let viewport = glLayer.getViewport(view);
  gl.viewport(viewport.x, viewport.y, viewport.width, viewport.height);

  /* ... */

  mat4.multiply(modelViewMatrix, view.transform.inverse.matrix, objectMatrix);
  gl.uniformMatrix4fv(programInfo.uniformLocations.modelViewMatrix,
                      false, modelViewMatrix);

  /* ... */
}

This outline of a renderer's core code shows how the pose's view gets represented by taking its transform's inverse's matrix as the model view matrix used to transform objects based on the viewer's position and orientation. The inverse's matrix is multiplied by the object's matrix to get the model view matrix, which is then passed into the shader program by setting a uniform to contain that information.

Specifications

Specification	Status	Comment
WebXR Device APIThe definition of 'XRRigidTransform.inverse' 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
inverse	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

XRRigidTransform.inverse by Mozilla Contributors is licensed under CC-BY-SA 2.5.