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#pragma BLENDER_REQUIRE(common_view_lib.glsl)
#pragma BLENDER_REQUIRE(common_math_geom_lib.glsl)
#pragma BLENDER_REQUIRE(common_utiltex_lib.glsl)
#pragma BLENDER_REQUIRE(lights_lib.glsl)
in vec4 uvcoordsvar;
out vec4 FragColor;
uniform sampler2D depthBuffer;
uniform sampler1D sssTexProfile;
uniform sampler2D sssRadius;
uniform sampler2DArray sssShadowCubes;
uniform sampler2DArray sssShadowCascades;
#define MAX_SSS_SAMPLES 65
#define SSS_LUT_SIZE 64.0
#define SSS_LUT_SCALE ((SSS_LUT_SIZE - 1.0) / float(SSS_LUT_SIZE))
#define SSS_LUT_BIAS (0.5 / float(SSS_LUT_SIZE))
layout(std140) uniform sssProfile
{
vec4 kernel[MAX_SSS_SAMPLES];
vec4 radii_max_radius;
int sss_samples;
};
vec3 sss_profile(float s)
{
s /= radii_max_radius.w;
return texture(sssTexProfile, saturate(s) * SSS_LUT_SCALE + SSS_LUT_BIAS).rgb;
}
float light_translucent_power_with_falloff(LightData ld, vec3 N, vec4 l_vector)
{
float power, falloff;
/* XXX : Removing Area Power. */
/* TODO : put this out of the shader. */
if (ld.l_type >= AREA_RECT) {
power = (ld.l_sizex * ld.l_sizey * 4.0 * M_PI) * (1.0 / 80.0);
if (ld.l_type == AREA_ELLIPSE) {
power *= M_PI * 0.25;
}
power *= 0.3 * 20.0 *
max(0.0, dot(-ld.l_forward, l_vector.xyz / l_vector.w)); /* XXX ad hoc, empirical */
power /= (l_vector.w * l_vector.w);
falloff = dot(N, l_vector.xyz / l_vector.w);
}
else if (ld.l_type == SUN) {
power = 1.0 / (1.0 + (ld.l_radius * ld.l_radius * 0.5));
power *= ld.l_radius * ld.l_radius * M_PI; /* Removing area light power*/
power *= M_2PI * 0.78; /* Matching cycles with point light. */
power *= 0.082; /* XXX ad hoc, empirical */
falloff = dot(N, -ld.l_forward);
}
else {
power = (4.0 * ld.l_radius * ld.l_radius) * (1.0 / 10.0);
power *= 1.5; /* XXX ad hoc, empirical */
power /= (l_vector.w * l_vector.w);
falloff = dot(N, l_vector.xyz / l_vector.w);
}
/* No transmittance at grazing angle (hide artifacts) */
return power * saturate(falloff * 2.0);
}
/* Some driver poorly optimize this code. Use direct reference to matrices. */
#define sd(x) shadows_data[x]
#define scube(x) shadows_cube_data[x]
#define scascade(x) shadows_cascade_data[x]
float shadow_cube_radial_depth(vec3 cubevec, float tex_id, int shadow_id)
{
float depth = sample_cube(sssShadowCubes, cubevec, tex_id).r;
/* To reverting the constant bias from shadow rendering. (Tweaked for 16bit shadowmaps) */
const float depth_bias = 3.1e-5;
depth = saturate(depth - depth_bias);
depth = linear_depth(true, depth, sd(shadow_id).sh_far, sd(shadow_id).sh_near);
depth *= length(cubevec / max_v3(abs(cubevec)));
return depth;
}
vec3 light_translucent(LightData ld, vec3 P, vec3 N, vec4 l_vector, vec2 rand, float sss_scale)
{
int shadow_id = int(ld.l_shadowid);
vec4 L = (ld.l_type != SUN) ? l_vector : vec4(-ld.l_forward, 1.0);
/* We use the full l_vector.xyz so that the spread is minimize
* if the shading point is further away from the light source */
/* TODO(fclem): do something better than this. */
vec3 T, B;
make_orthonormal_basis(L.xyz / L.w, T, B);
vec3 n;
vec4 depths;
float d, dist;
int data_id = int(sd(shadow_id).sh_data_index);
if (ld.l_type == SUN) {
vec4 view_z = vec4(dot(P - cameraPos, cameraForward));
vec4 weights = step(scascade(data_id).split_end_distances, view_z);
float id = abs(4.0 - dot(weights, weights));
if (id > 3.0) {
return vec3(0.0);
}
/* Same factor as in get_cascade_world_distance(). */
float range = abs(sd(shadow_id).sh_far - sd(shadow_id).sh_near);
vec4 shpos = scascade(data_id).shadowmat[int(id)] * vec4(P, 1.0);
dist = shpos.z * range;
if (shpos.z > 1.0 || shpos.z < 0.0) {
return vec3(0.0);
}
float tex_id = scascade(data_id).sh_tex_index + id;
/* Assume cascades have same height and width. */
vec2 ofs = vec2(1.0, 0.0) / float(textureSize(sssShadowCascades, 0).x);
d = sample_cascade(sssShadowCascades, shpos.xy, tex_id).r;
depths.x = sample_cascade(sssShadowCascades, shpos.xy + ofs.xy, tex_id).r;
depths.y = sample_cascade(sssShadowCascades, shpos.xy + ofs.yx, tex_id).r;
depths.z = sample_cascade(sssShadowCascades, shpos.xy - ofs.xy, tex_id).r;
depths.w = sample_cascade(sssShadowCascades, shpos.xy - ofs.yx, tex_id).r;
/* To reverting the constant bias from shadow rendering. (Tweaked for 16bit shadowmaps) */
float depth_bias = 3.1e-5;
depths = saturate(depths - depth_bias);
d = saturate(d - depth_bias);
/* Size of a texel in world space.
* FIXME This is only correct if l_right is the same right vector used for shadowmap creation.
* This won't work if the shadow matrix is rotated (soft shadows).
* TODO precompute */
float unit_world_in_uv_space = length(mat3(scascade(data_id).shadowmat[int(id)]) * ld.l_right);
float dx_scale = 2.0 * ofs.x / unit_world_in_uv_space;
d *= range;
depths *= range;
/* This is the normal of the occluder in world space. */
// vec3 T = ld.l_forward * dx + ld.l_right * dx_scale;
// vec3 B = ld.l_forward * dy + ld.l_up * dx_scale;
// n = normalize(cross(T, B));
}
else {
float ofs = 1.0 / float(textureSize(sssShadowCubes, 0).x);
vec3 cubevec = transform_point(scube(data_id).shadowmat, P);
dist = length(cubevec);
cubevec /= dist;
/* tex_id == data_id for cube shadowmap */
float tex_id = float(data_id);
d = shadow_cube_radial_depth(cubevec, tex_id, shadow_id);
/* NOTE: The offset is irregular in respect to cubeface uvs. But it has
* a much more uniform behavior than biasing based on face derivatives. */
depths.x = shadow_cube_radial_depth(cubevec + T * ofs, tex_id, shadow_id);
depths.y = shadow_cube_radial_depth(cubevec + B * ofs, tex_id, shadow_id);
depths.z = shadow_cube_radial_depth(cubevec - T * ofs, tex_id, shadow_id);
depths.w = shadow_cube_radial_depth(cubevec - B * ofs, tex_id, shadow_id);
}
float dx = depths.x - depths.z;
float dy = depths.y - depths.w;
float s = min(d, min_v4(depths));
/* To avoid light leak from depth discontinuity and shadowmap aliasing. */
float slope_bias = (abs(dx) + abs(dy)) * 0.5;
s -= slope_bias;
float delta = dist - s;
float power = light_translucent_power_with_falloff(ld, N, l_vector);
return power * sss_profile(abs(delta) / sss_scale);
}
#undef sd
#undef scube
#undef scsmd
void main(void)
{
vec2 uvs = uvcoordsvar.xy;
float sss_scale = texture(sssRadius, uvs).r;
vec3 P = get_world_space_from_depth(uvs, texture(depthBuffer, uvs).r);
vec3 N = normalize(cross(dFdx(P), dFdy(P)));
vec3 rand = texelfetch_noise_tex(gl_FragCoord.xy).zwy;
rand.xy *= fast_sqrt(rand.z);
vec3 accum = vec3(0.0);
for (int i = 0; i < MAX_LIGHT && i < laNumLight; i++) {
LightData ld = lights_data[i];
/* Only shadowed light can produce translucency */
if (ld.l_shadowid < 0.0) {
continue;
}
vec4 l_vector; /* Non-Normalized Light Vector with length in last component. */
l_vector.xyz = ld.l_position - P;
l_vector.w = length(l_vector.xyz);
float att = light_attenuation(ld, l_vector);
if (att < 1e-8) {
continue;
}
accum += att * ld.l_color * light_translucent(ld, P, -N, l_vector, rand.xy, sss_scale);
}
FragColor = vec4(accum, 1.0);
}
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