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38 行
1.3 KiB
38 行
1.3 KiB
#ifndef UNITY_COMMON_LIGHTING_INCLUDED
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#define UNITY_COMMON_LIGHTING_INCLUDED
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//-----------------------------------------------------------------------------
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// Attenuation functions
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//-----------------------------------------------------------------------------
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// Ref: Moving Frostbite to PBR
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float SmoothDistanceAttenuation(float squaredDistance, float invSqrAttenuationRadius)
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{
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float factor = squaredDistance * invSqrAttenuationRadius;
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float smoothFactor = saturate(1.0f - factor * factor);
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return smoothFactor * smoothFactor;
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}
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#define PUNCTUAL_LIGHT_THRESHOLD 0.01 // 1cm (in Unity 1 is 1m)
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float GetDistanceAttenuation(float3 unL, float invSqrAttenuationRadius)
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{
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float sqrDist = dot(unL, unL);
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float attenuation = 1.0f / (max(PUNCTUAL_LIGHT_THRESHOLD * PUNCTUAL_LIGHT_THRESHOLD, sqrDist));
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// Non physically based hack to limit light influence to attenuationRadius.
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attenuation *= SmoothDistanceAttenuation(sqrDist, invSqrAttenuationRadius);
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return attenuation;
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}
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float GetAngleAttenuation(float3 L, float3 lightDir, float lightAngleScale, float lightAngleOffset)
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{
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float cd = dot(lightDir, L);
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float attenuation = saturate(cd * lightAngleScale + lightAngleOffset);
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// smooth the transition
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attenuation *= attenuation;
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return attenuation;
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}
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#endif // UNITY_COMMON_LIGHTING_INCLUDED
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