16 lines
496 B
HLSL
16 lines
496 B
HLSL
// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
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#ifndef __IES_PROFILE__
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#define __IES_PROFILE__
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// Calculate IES light profile from 1D texture
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float ComputeLightProfileMultiplier(Texture2D tex, float3 worldPosition, float3 lightPosition, float3 lightDirection)
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{
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float3 l = normalize(worldPosition - lightPosition);
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float d = dot(l, lightDirection);
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float angle = asin(d) / PI + 0.5f;
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return tex.SampleLevel(SamplerLinearClamp, float2(angle, 0), 0).r;
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}
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#endif
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