The read-only sphericalHarmonicsCoefficients property of the XRLightEstimate interface returns a Float32Array containing 9 spherical harmonics coefficients.

Spherical harmonic lighting is a technique that uses spherical functions instead of standard lighting equations. See Wikipedia for more information.

A Float32Array containing 9 spherical harmonics coefficients. The array contains 27 elements in total, with every 3 elements defining red, green, and blue components for each coefficient.

The first 3 elements must be a valid lighting estimate component; the rest may be 0 due to privacy settings or limitations of the device to provide more data.

Within an XRFrame loop, you can use the sphericalHarmonicsCoefficients property to light the scene.

const lightProbe = await xrSession.requestLightProbe();

// frame loop
function onXRFrame(time, xrFrame) {
  let lightEstimate = xrFrame.getLightEstimate(lightProbe);

  // Render lights using lightEstimate.sphericalHarmonicsCoefficients
}

• XRFrame.getLightEstimate()