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XRView: requestViewportScale() method

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The requestViewportScale() method of the XRView interface requests that the user agent sets the requested viewport scale for this viewport to the given value. This is used for dynamic viewport scaling which allows rendering to a subset of the WebXR viewport using a scale factor that can be changed every animation frame.

Syntax

js

requestViewportScale(scale)

Parameters

scale

A number greater than 0.0 and less than or equal to 1.0 representing the scale factor.

Return value

None (undefined).

Dynamic viewport scaling

Dynamic viewport scaling allows applications to only use a subset of the available framebuffer. The feature may not be available on all systems since it depends on driver support, so you might want to ensure that requestViewportScale() exists before calling it.

The scale parameter can be a number greater than 0.0 and less than or equal to 1.0.

Alternatively, you can use the XRView.recommendedViewportScale property which contains the user agent's recommended value based on internal heuristics. If the user agent doesn't provide a recommended viewport scale, its value is null and the call to requestViewportScale() is ignored.

Examples

The following example shows how to request and apply a new viewport scale. The call to XRWebGLLayer.getViewport() applies the change and returns the updated viewport.

js

for (const view of pose.views) {
  if (view.requestViewportScale) {
    view.requestViewportScale(0.8);
    // or use view.requestViewportScale(view.recommendedViewportScale);
  }
  const viewport = glLayer.getViewport(view);
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
requestViewportScale 90 90 No No 76 No No 90 No 64 No 15.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/XRView/requestViewportScale