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#pragma BLENDER_REQUIRE(common_view_lib.glsl)
#pragma BLENDER_REQUIRE(common_math_lib.glsl)
#pragma BLENDER_REQUIRE(common_utiltex_lib.glsl)
#pragma BLENDER_REQUIRE(common_uniforms_lib.glsl)
/* Based on Separable SSS. by Jorge Jimenez and Diego Gutierrez */
#define MAX_SSS_SAMPLES 65
layout(std140) uniform sssProfile
{
vec4 kernel[MAX_SSS_SAMPLES];
vec4 radii_max_radius;
int sss_samples;
};
uniform sampler2D depthBuffer;
uniform sampler2D sssIrradiance;
uniform sampler2D sssRadius;
uniform sampler2D sssAlbedo;
layout(location = 0) out vec4 sssRadiance;
void main(void)
{
vec2 pixel_size = 1.0 / vec2(textureSize(depthBuffer, 0).xy); /* TODO precompute */
vec2 uvs = gl_FragCoord.xy * pixel_size;
vec3 sss_irradiance = texture(sssIrradiance, uvs).rgb;
float sss_radius = texture(sssRadius, uvs).r * radii_max_radius.w;
float depth = texture(depthBuffer, uvs).r;
float depth_view = get_view_z_from_depth(depth);
float rand = texelfetch_noise_tex(gl_FragCoord.xy).r;
#ifdef FIRST_PASS
float angle = M_2PI * rand + M_PI_2;
vec2 dir = vec2(1.0, 0.0);
#else /* SECOND_PASS */
float angle = M_2PI * rand;
vec2 dir = vec2(0.0, 1.0);
#endif
vec2 dir_rand = vec2(cos(angle), sin(angle));
/* Compute kernel bounds in 2D. */
float homcoord = ProjectionMatrix[2][3] * depth_view + ProjectionMatrix[3][3];
vec2 scale = vec2(ProjectionMatrix[0][0], ProjectionMatrix[1][1]) * sss_radius / homcoord;
vec2 finalStep = scale * 0.5; /* samples range -1..1 */
float sss_radius_inv = 1.0 / max(1e-8, sss_radius);
/* Center sample */
vec3 accum = sss_irradiance * kernel[0].rgb;
for (int i = 1; i < sss_samples && i < MAX_SSS_SAMPLES; i++) {
vec2 sample_uv = uvs + kernel[i].a * finalStep *
((abs(kernel[i].a) > sssJitterThreshold) ? dir : dir_rand);
vec3 color = texture(sssIrradiance, sample_uv).rgb;
float sample_depth = texture(depthBuffer, sample_uv).r;
sample_depth = get_view_z_from_depth(sample_depth);
/* Depth correction factor. See Real Time Realistic Skin Translucency 2010
* by Jimenez, eqs. 2 and 9, and D9740.
* Coefficient -2 follows from gaussian_profile() from gpu_material.c and
* from the definition of finalStep. */
float depth_delta = (depth_view - sample_depth) * sss_radius_inv;
float s = exp(-2.0 * sqr(depth_delta));
/* Out of view samples. */
if (any(lessThan(sample_uv, vec2(0.0))) || any(greaterThan(sample_uv, vec2(1.0)))) {
s = 0.0;
}
/* Mix with first sample in failure case and apply kernel color. */
accum += kernel[i].rgb * mix(sss_irradiance, color, s);
}
#if defined(FIRST_PASS)
sssRadiance = vec4(accum, 1.0);
#else /* SECOND_PASS */
sssRadiance = vec4(accum * texture(sssAlbedo, uvs).rgb, 1.0);
#endif
}
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