@animech-public/playcanvas/build/playcanvas.prf/src/scene/shader-lib/chunks/lit/frag/shadowVSM_common.js

PlayCanvas WebGL game engine

var shadowVSM_commonPS = `
float linstep(float a, float b, float v) {
	return saturate((v - a) / (b - a));
}
float reduceLightBleeding(float pMax, float amount) {
	 return linstep(amount, 1.0, pMax);
}
float chebyshevUpperBound(vec2 moments, float mean, float minVariance, float lightBleedingReduction) {
	float variance = moments.y - (moments.x * moments.x);
	variance = max(variance, minVariance);
	float d = mean - moments.x;
	float pMax = variance / (variance + (d * d));
	pMax = reduceLightBleeding(pMax, lightBleedingReduction);
	return (mean <= moments.x ? 1.0 : pMax);
}
float calculateEVSM(vec3 moments, float Z, float vsmBias, float exponent) {
	Z = 2.0 * Z - 1.0;
	float warpedDepth = exp(exponent * Z);
	moments.xy += vec2(warpedDepth, warpedDepth*warpedDepth) * (1.0 - moments.z);
	float VSMBias = vsmBias;
	float depthScale = VSMBias * exponent * warpedDepth;
	float minVariance1 = depthScale * depthScale;
	return chebyshevUpperBound(moments.xy, warpedDepth, minVariance1, 0.1);
}
`;

export { shadowVSM_commonPS as default };