first commit

public/sdk/three/jsm/nodes/lighting/LightUtils.js

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+import { tslFn } from '../shadernode/ShaderNode.js';
+
+export const getDistanceAttenuation = tslFn( ( inputs ) => {
+
+	const { lightDistance, cutoffDistance, decayExponent } = inputs;
+
+	// based upon Frostbite 3 Moving to Physically-based Rendering
+	// page 32, equation 26: E[window1]
+	// https://seblagarde.files.wordpress.com/2015/07/course_notes_moving_frostbite_to_pbr_v32.pdf
+	const distanceFalloff = lightDistance.pow( decayExponent ).max( 0.01 ).reciprocal();
+
+	return cutoffDistance.greaterThan( 0 ).cond(
+		distanceFalloff.mul( lightDistance.div( cutoffDistance ).pow4().oneMinus().clamp().pow2() ),
+		distanceFalloff
+	);
+
+} ); // validated