Differential D16243 Diff 58431 source/blender/draw/engines/eevee/shaders/btdf_lut_frag.glsl

Changeset View

Standalone View

source/blender/draw/engines/eevee/shaders/btdf_lut_frag.glsl

#pragma BLENDER_REQUIRE(common_utiltex_lib.glsl)		#pragma BLENDER_REQUIRE(common_utiltex_lib.glsl)
#pragma BLENDER_REQUIRE(bsdf_sampling_lib.glsl)		#pragma BLENDER_REQUIRE(bsdf_sampling_lib.glsl)

uniform float sampleCount;
uniform float z;

out vec4 FragColor;

void main()		void main()
{		{
float x = floor(gl_FragCoord.x) / (LUT_SIZE - 1.0);		float x = floor(gl_FragCoord.x) / (LUT_SIZE - 1.0);
float y = floor(gl_FragCoord.y) / (LUT_SIZE - 1.0);		float y = floor(gl_FragCoord.y) / (LUT_SIZE - 1.0);

float ior = clamp(sqrt(x), 0.05, 0.999);		float ior = clamp(sqrt(x), 0.05, 0.999);
/* ior is sin of critical angle. */		/* ior is sin of critical angle. */
float critical_cos = sqrt(1.0 - saturate(ior * ior));		float critical_cos = sqrt(1.0 - saturate(ior * ior));

y = y * 2.0 - 1.0;		y = y * 2.0 - 1.0;
/* Maximize texture usage on both sides of the critical angle. */		/* Maximize texture usage on both sides of the critical angle. */
y *= (y > 0.0) ? (1.0 - critical_cos) : critical_cos;		y *= (y > 0.0) ? (1.0 - critical_cos) : critical_cos;
/* Center LUT around critical angle to avoid strange interpolation issues when the critical		/* Center LUT around critical angle to avoid strange interpolation issues when the critical
* angle is changing. */		* angle is changing. */
y += critical_cos;		y += critical_cos;
float NV = clamp(y, 1e-4, 0.9999);		float NV = clamp(y, 1e-4, 0.9999);

float a = z * z;		float a = z_factor * z_factor;
float a2 = clamp(a * a, 1e-8, 0.9999);		float a2 = clamp(a * a, 1e-8, 0.9999);

vec3 V = vec3(sqrt(1.0 - NV * NV), 0.0, NV);		vec3 V = vec3(sqrt(1.0 - NV * NV), 0.0, NV);

/* Integrating BTDF */		/* Integrating BTDF */
float btdf_accum = 0.0;		float btdf_accum = 0.0;
float fresnel_accum = 0.0;		float fresnel_accum = 0.0;
for (float j = 0.0; j < sampleCount; j++) {		for (float j = 0.0; j < sampleCount; j++) {
Show All 32 Lines	for (float i = 0.0; i < sampleCount; i++) {

btdf_accum += btdf;		btdf_accum += btdf;
}		}
}		}
}		}
btdf_accum /= sampleCount * sampleCount;		btdf_accum /= sampleCount * sampleCount;
fresnel_accum /= sampleCount * sampleCount;		fresnel_accum /= sampleCount * sampleCount;

if (z == 0.0) {		if (z_factor == 0.0) {
/* Perfect mirror. Increased precision because the roughness is clamped. */		/* Perfect mirror. Increased precision because the roughness is clamped. */
fresnel_accum = F_eta(ior, NV);		fresnel_accum = F_eta(ior, NV);
}		}

if (x == 0.0) {		if (x == 0.0) {
/* Special case. */		/* Special case. */
fresnel_accum = 1.0;		fresnel_accum = 1.0;
btdf_accum = 0.0;		btdf_accum = 0.0;
}		}

/* There is place to put multi-scatter result (which is a little bit different still)		/* There is place to put multi-scatter result (which is a little bit different still)
* and / or lobe fitting for better sampling of. */		* and / or lobe fitting for better sampling of. */
FragColor = vec4(btdf_accum, fresnel_accum, 0.0, 1.0);		FragColor = vec4(btdf_accum, fresnel_accum, 0.0, 1.0);
}		}