14 lines
552 B
GLSL
14 lines
552 B
GLSL
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// Sun Most Representative Point (used for MRP area lighting method)
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// From "Frostbite going PBR" paper
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vec3 SunMRP(vec3 normal, vec3 eyedir)
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{
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vec3 local_sundir = normalize((transpose(InverseViewMatrix) * vec4(sun_direction, 0.)).xyz);
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vec3 R = reflect(-eyedir, normal);
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float angularRadius = 3.14 * sun_angle / 180.;
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vec3 D = local_sundir;
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float d = cos(angularRadius);
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float r = sin(angularRadius);
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float DdotR = dot(D, R);
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vec3 S = R - DdotR * D;
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return (DdotR < d) ? normalize(d * D + normalize (S) * r) : R;
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}
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