files/en-us/web/api/xrlightestimate/sphericalharmonicscoefficients/index.md
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The read-only sphericalHarmonicsCoefficients property of the {{DOMxRef("XRLightEstimate")}} interface returns a {{jsxref("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 {{jsxref("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 {{domxref("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
}
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