godot/modules/lightmapper_rd/lm_compute.glsl

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#[versions]
primary = "#define MODE_DIRECT_LIGHT";
secondary = "#define MODE_BOUNCE_LIGHT";
dilate = "#define MODE_DILATE";
unocclude = "#define MODE_UNOCCLUDE";
light_probes = "#define MODE_LIGHT_PROBES";
denoise = "#define MODE_DENOISE";
#[compute]
#version 450
#VERSION_DEFINES
// One 2D local group focusing in one layer at a time, though all
// in parallel (no barriers) makes more sense than a 3D local group
// as this can take more advantage of the cache for each group.
#ifdef MODE_LIGHT_PROBES
layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
#else
layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
#endif
#include "lm_common_inc.glsl"
#ifdef MODE_LIGHT_PROBES
layout(set = 1, binding = 0, std430) restrict buffer LightProbeData {
vec4 data[];
}
light_probes;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
layout(set = 1, binding = 2) uniform texture2DArray source_direct_light; //also need the direct light, which was omitted
layout(set = 1, binding = 3) uniform texture2D environment;
#endif
#ifdef MODE_UNOCCLUDE
layout(rgba32f, set = 1, binding = 0) uniform restrict image2DArray position;
layout(rgba32f, set = 1, binding = 1) uniform restrict readonly image2DArray unocclude;
#endif
#if defined(MODE_DIRECT_LIGHT) || defined(MODE_BOUNCE_LIGHT)
layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly image2DArray dest_light;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
layout(set = 1, binding = 2) uniform texture2DArray source_position;
layout(set = 1, binding = 3) uniform texture2DArray source_normal;
layout(rgba16f, set = 1, binding = 4) uniform restrict image2DArray accum_light;
#endif
#ifdef MODE_BOUNCE_LIGHT
layout(rgba32f, set = 1, binding = 5) uniform restrict image2DArray bounce_accum;
layout(set = 1, binding = 6) uniform texture2D environment;
#endif
#ifdef MODE_DIRECT_LIGHT
layout(rgba32f, set = 1, binding = 5) uniform restrict writeonly image2DArray primary_dynamic;
#endif
#if defined(MODE_DILATE) || defined(MODE_DENOISE)
layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly image2DArray dest_light;
layout(set = 1, binding = 1) uniform texture2DArray source_light;
#endif
#ifdef MODE_DENOISE
layout(set = 1, binding = 2) uniform texture2DArray source_normal;
layout(set = 1, binding = 3) uniform DenoiseParams {
float spatial_bandwidth;
float light_bandwidth;
float albedo_bandwidth;
float normal_bandwidth;
float filter_strength;
}
denoise_params;
#endif
layout(push_constant, std430) uniform Params {
ivec2 atlas_size; // x used for light probe mode total probes
uint ray_count;
uint ray_to;
vec3 world_size;
float bias;
vec3 to_cell_offset;
uint ray_from;
vec3 to_cell_size;
uint light_count;
int grid_size;
int atlas_slice;
ivec2 region_ofs;
mat3x4 env_transform;
}
params;
//check it, but also return distance and barycentric coords (for uv lookup)
bool ray_hits_triangle(vec3 from, vec3 dir, float max_dist, vec3 p0, vec3 p1, vec3 p2, out float r_distance, out vec3 r_barycentric) {
const float EPSILON = 0.00001;
const vec3 e0 = p1 - p0;
const vec3 e1 = p0 - p2;
vec3 triangle_normal = cross(e1, e0);
float n_dot_dir = dot(triangle_normal, dir);
if (abs(n_dot_dir) < EPSILON) {
return false;
}
const vec3 e2 = (p0 - from) / n_dot_dir;
const vec3 i = cross(dir, e2);
r_barycentric.y = dot(i, e1);
r_barycentric.z = dot(i, e0);
r_barycentric.x = 1.0 - (r_barycentric.z + r_barycentric.y);
r_distance = dot(triangle_normal, e2);
return (r_distance > params.bias) && (r_distance < max_dist) && all(greaterThanEqual(r_barycentric, vec3(0.0)));
}
const uint RAY_MISS = 0;
const uint RAY_FRONT = 1;
const uint RAY_BACK = 2;
const uint RAY_ANY = 3;
uint trace_ray(vec3 p_from, vec3 p_to
#if defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
,
out uint r_triangle, out vec3 r_barycentric
#endif
#if defined(MODE_UNOCCLUDE)
,
out float r_distance, out vec3 r_normal
#endif
) {
/* world coords */
vec3 rel = p_to - p_from;
float rel_len = length(rel);
vec3 dir = normalize(rel);
vec3 inv_dir = 1.0 / dir;
/* cell coords */
vec3 from_cell = (p_from - params.to_cell_offset) * params.to_cell_size;
vec3 to_cell = (p_to - params.to_cell_offset) * params.to_cell_size;
//prepare DDA
vec3 rel_cell = to_cell - from_cell;
ivec3 icell = ivec3(from_cell);
ivec3 iendcell = ivec3(to_cell);
vec3 dir_cell = normalize(rel_cell);
vec3 delta = min(abs(1.0 / dir_cell), params.grid_size); // use params.grid_size as max to prevent infinity values
ivec3 step = ivec3(sign(rel_cell));
vec3 side = (sign(rel_cell) * (vec3(icell) - from_cell) + (sign(rel_cell) * 0.5) + 0.5) * delta;
uint iters = 0;
while (all(greaterThanEqual(icell, ivec3(0))) && all(lessThan(icell, ivec3(params.grid_size))) && iters < 1000) {
uvec2 cell_data = texelFetch(usampler3D(grid, linear_sampler), icell, 0).xy;
if (cell_data.x > 0) { //triangles here
uint hit = RAY_MISS;
float best_distance = 1e20;
for (uint i = 0; i < cell_data.x; i++) {
uint tidx = grid_indices.data[cell_data.y + i];
//Ray-Box test
Triangle triangle = triangles.data[tidx];
vec3 t0 = (triangle.min_bounds - p_from) * inv_dir;
vec3 t1 = (triangle.max_bounds - p_from) * inv_dir;
vec3 tmin = min(t0, t1), tmax = max(t0, t1);
if (max(tmin.x, max(tmin.y, tmin.z)) > min(tmax.x, min(tmax.y, tmax.z))) {
continue; //ray box failed
}
//prepare triangle vertices
vec3 vtx0 = vertices.data[triangle.indices.x].position;
vec3 vtx1 = vertices.data[triangle.indices.y].position;
vec3 vtx2 = vertices.data[triangle.indices.z].position;
#if defined(MODE_UNOCCLUDE) || defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
vec3 normal = -normalize(cross((vtx0 - vtx1), (vtx0 - vtx2)));
bool backface = dot(normal, dir) >= 0.0;
#endif
float distance;
vec3 barycentric;
if (ray_hits_triangle(p_from, dir, rel_len, vtx0, vtx1, vtx2, distance, barycentric)) {
#ifdef MODE_DIRECT_LIGHT
return RAY_ANY; //any hit good
#endif
#if defined(MODE_UNOCCLUDE) || defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
if (!backface) {
// the case of meshes having both a front and back face in the same plane is more common than
// expected, so if this is a front-face, bias it closer to the ray origin, so it always wins over the back-face
distance = max(params.bias, distance - params.bias);
}
if (distance < best_distance) {
hit = backface ? RAY_BACK : RAY_FRONT;
best_distance = distance;
#if defined(MODE_UNOCCLUDE)
r_distance = distance;
r_normal = normal;
#endif
#if defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
r_triangle = tidx;
r_barycentric = barycentric;
#endif
}
#endif
}
}
#if defined(MODE_UNOCCLUDE) || defined(MODE_BOUNCE_LIGHT) || defined(MODE_LIGHT_PROBES)
if (hit != RAY_MISS) {
return hit;
}
#endif
}
if (icell == iendcell) {
break;
}
bvec3 mask = lessThanEqual(side.xyz, min(side.yzx, side.zxy));
side += vec3(mask) * delta;
icell += ivec3(vec3(mask)) * step;
iters++;
}
return RAY_MISS;
}
// https://www.reedbeta.com/blog/hash-functions-for-gpu-rendering/
uint hash(uint value) {
uint state = value * 747796405u + 2891336453u;
uint word = ((state >> ((state >> 28u) + 4u)) ^ state) * 277803737u;
return (word >> 22u) ^ word;
}
uint random_seed(ivec3 seed) {
return hash(seed.x ^ hash(seed.y ^ hash(seed.z)));
}
// generates a random value in range [0.0, 1.0)
float randomize(inout uint value) {
value = hash(value);
return float(value / 4294967296.0);
}
const float PI = 3.14159265f;
// http://www.realtimerendering.com/raytracinggems/unofficial_RayTracingGems_v1.4.pdf (chapter 15)
vec3 generate_hemisphere_uniform_direction(inout uint noise) {
float noise1 = randomize(noise);
float noise2 = randomize(noise) * 2.0 * PI;
float factor = sqrt(1 - (noise1 * noise1));
return vec3(factor * cos(noise2), factor * sin(noise2), noise1);
}
vec3 generate_hemisphere_cosine_weighted_direction(inout uint noise) {
float noise1 = randomize(noise);
float noise2 = randomize(noise) * 2.0 * PI;
return vec3(sqrt(noise1) * cos(noise2), sqrt(noise1) * sin(noise2), sqrt(1.0 - noise1));
}
float get_omni_attenuation(float distance, float inv_range, float decay) {
float nd = distance * inv_range;
nd *= nd;
nd *= nd; // nd^4
nd = max(1.0 - nd, 0.0);
nd *= nd; // nd^2
return nd * pow(max(distance, 0.0001), -decay);
}
void main() {
#ifdef MODE_LIGHT_PROBES
int probe_index = int(gl_GlobalInvocationID.x);
if (probe_index >= params.atlas_size.x) { //too large, do nothing
return;
}
#else
ivec2 atlas_pos = ivec2(gl_GlobalInvocationID.xy) + params.region_ofs;
if (any(greaterThanEqual(atlas_pos, params.atlas_size))) { //too large, do nothing
return;
}
#endif
#ifdef MODE_DIRECT_LIGHT
vec3 normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
if (length(normal) < 0.5) {
return; //empty texel, no process
}
vec3 position = texelFetch(sampler2DArray(source_position, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
//go through all lights
//start by own light (emissive)
vec3 static_light = vec3(0.0);
vec3 dynamic_light = vec3(0.0);
#ifdef USE_SH_LIGHTMAPS
vec4 sh_accum[4] = vec4[](
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0));
#endif
for (uint i = 0; i < params.light_count; i++) {
vec3 light_pos;
float dist;
float attenuation;
float soft_shadowing_disk_size;
if (lights.data[i].type == LIGHT_TYPE_DIRECTIONAL) {
vec3 light_vec = lights.data[i].direction;
light_pos = position - light_vec * length(params.world_size);
dist = length(params.world_size);
attenuation = 1.0;
soft_shadowing_disk_size = lights.data[i].size;
} else {
light_pos = lights.data[i].position;
dist = distance(position, light_pos);
if (dist > lights.data[i].range) {
continue;
}
soft_shadowing_disk_size = lights.data[i].size / dist;
attenuation = get_omni_attenuation(dist, 1.0 / lights.data[i].range, lights.data[i].attenuation);
if (lights.data[i].type == LIGHT_TYPE_SPOT) {
vec3 rel = normalize(position - light_pos);
float cos_spot_angle = lights.data[i].cos_spot_angle;
float cos_angle = dot(rel, lights.data[i].direction);
if (cos_angle < cos_spot_angle) {
continue; //invisible, dont try
}
float scos = max(cos_angle, cos_spot_angle);
float spot_rim = max(0.0001, (1.0 - scos) / (1.0 - cos_spot_angle));
attenuation *= 1.0 - pow(spot_rim, lights.data[i].inv_spot_attenuation);
}
}
vec3 light_dir = normalize(light_pos - position);
attenuation *= max(0.0, dot(normal, light_dir));
if (attenuation <= 0.0001) {
continue; //no need to do anything
}
float penumbra = 0.0;
if (lights.data[i].size > 0.0) {
vec3 light_to_point = -light_dir;
vec3 aux = light_to_point.y < 0.777 ? vec3(0.0, 1.0, 0.0) : vec3(1.0, 0.0, 0.0);
vec3 light_to_point_tan = normalize(cross(light_to_point, aux));
vec3 light_to_point_bitan = normalize(cross(light_to_point, light_to_point_tan));
const uint shadowing_rays_check_penumbra_denom = 2;
uint shadowing_ray_count = params.ray_count;
uint hits = 0;
uint noise = random_seed(ivec3(atlas_pos, 43573547 /* some prime */));
vec3 light_disk_to_point = light_to_point;
for (uint j = 0; j < shadowing_ray_count; j++) {
// Optimization:
// Once already traced an important proportion of rays, if all are hits or misses,
// assume we're not in the penumbra so we can infer the rest would have the same result
if (j == shadowing_ray_count / shadowing_rays_check_penumbra_denom) {
if (hits == j) {
// Assume totally lit
hits = shadowing_ray_count;
break;
} else if (hits == 0) {
// Assume totally dark
hits = 0;
break;
}
}
float r = randomize(noise);
float a = randomize(noise) * 2.0 * PI;
vec2 disk_sample = (r * vec2(cos(a), sin(a))) * soft_shadowing_disk_size * lights.data[i].shadow_blur;
light_disk_to_point = normalize(light_to_point + disk_sample.x * light_to_point_tan + disk_sample.y * light_to_point_bitan);
if (trace_ray(position - light_disk_to_point * params.bias, position - light_disk_to_point * dist) == RAY_MISS) {
hits++;
}
}
penumbra = float(hits) / float(shadowing_ray_count);
} else {
if (trace_ray(position + light_dir * params.bias, light_pos) == RAY_MISS) {
penumbra = 1.0;
}
}
vec3 light = lights.data[i].color * lights.data[i].energy * attenuation * penumbra;
if (lights.data[i].static_bake) {
static_light += light;
#ifdef USE_SH_LIGHTMAPS
float c[4] = float[](
0.282095, //l0
0.488603 * light_dir.y, //l1n1
0.488603 * light_dir.z, //l1n0
0.488603 * light_dir.x //l1p1
);
for (uint j = 0; j < 4; j++) {
sh_accum[j].rgb += light * c[j] * 8.0;
}
#endif
} else {
dynamic_light += light;
}
}
vec3 albedo = texelFetch(sampler2DArray(albedo_tex, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).rgb;
vec3 emissive = texelFetch(sampler2DArray(emission_tex, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).rgb;
dynamic_light *= albedo; //if it will bounce, must multiply by albedo
dynamic_light += emissive;
//keep for lightprobes
imageStore(primary_dynamic, ivec3(atlas_pos, params.atlas_slice), vec4(dynamic_light, 1.0));
dynamic_light += static_light * albedo; //send for bounces
dynamic_light *= params.env_transform[2][3]; // exposure_normalization
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), vec4(dynamic_light, 1.0));
#ifdef USE_SH_LIGHTMAPS
//keep for adding at the end
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 0), sh_accum[0]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 1), sh_accum[1]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 2), sh_accum[2]);
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + 3), sh_accum[3]);
#else
static_light *= params.env_transform[2][3]; // exposure_normalization
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice), vec4(static_light, 1.0));
#endif
#endif
#ifdef MODE_BOUNCE_LIGHT
vec3 normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
if (length(normal) < 0.5) {
return; //empty texel, no process
}
vec3 position = texelFetch(sampler2DArray(source_position, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
vec3 v0 = abs(normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);
vec3 tangent = normalize(cross(v0, normal));
vec3 bitangent = normalize(cross(tangent, normal));
mat3 normal_mat = mat3(tangent, bitangent, normal);
#ifdef USE_SH_LIGHTMAPS
vec4 sh_accum[4] = vec4[](
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0),
vec4(0.0, 0.0, 0.0, 1.0));
#endif
vec3 light_average = vec3(0.0);
float active_rays = 0.0;
uint noise = random_seed(ivec3(params.ray_from, atlas_pos));
for (uint i = params.ray_from; i < params.ray_to; i++) {
vec3 ray_dir = normal_mat * generate_hemisphere_cosine_weighted_direction(noise);
uint tidx;
vec3 barycentric;
vec3 light = vec3(0.0);
uint trace_result = trace_ray(position + ray_dir * params.bias, position + ray_dir * length(params.world_size), tidx, barycentric);
if (trace_result == RAY_FRONT) {
//hit a triangle
vec2 uv0 = vertices.data[triangles.data[tidx].indices.x].uv;
vec2 uv1 = vertices.data[triangles.data[tidx].indices.y].uv;
vec2 uv2 = vertices.data[triangles.data[tidx].indices.z].uv;
vec3 uvw = vec3(barycentric.x * uv0 + barycentric.y * uv1 + barycentric.z * uv2, float(triangles.data[tidx].slice));
light = textureLod(sampler2DArray(source_light, linear_sampler), uvw, 0.0).rgb;
active_rays += 1.0;
} else if (trace_result == RAY_MISS) {
if (params.env_transform[0][3] == 0.0) { // Use env_transform[0][3] to indicate when we are computing the first bounce
// Did not hit a triangle, reach out for the sky
vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir);
vec2 st = vec2(
atan(sky_dir.x, sky_dir.z),
acos(sky_dir.y));
if (st.x < 0.0)
st.x += PI * 2.0;
st /= vec2(PI * 2.0, PI);
light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb;
}
active_rays += 1.0;
}
light_average += light;
#ifdef USE_SH_LIGHTMAPS
float c[4] = float[](
0.282095, //l0
0.488603 * ray_dir.y, //l1n1
0.488603 * ray_dir.z, //l1n0
0.488603 * ray_dir.x //l1p1
);
for (uint j = 0; j < 4; j++) {
sh_accum[j].rgb += light * c[j] * (8.0 / float(params.ray_count));
}
#endif
}
vec3 light_total;
if (params.ray_from == 0) {
light_total = vec3(0.0);
} else {
vec4 accum = imageLoad(bounce_accum, ivec3(atlas_pos, params.atlas_slice));
light_total = accum.rgb;
active_rays += accum.a;
}
light_total += light_average;
#ifdef USE_SH_LIGHTMAPS
for (int i = 0; i < 4; i++) {
vec4 accum = imageLoad(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + i));
accum.rgb += sh_accum[i].rgb;
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice * 4 + i), accum);
}
#endif
if (params.ray_to == params.ray_count) {
if (active_rays > 0) {
light_total /= active_rays;
}
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), vec4(light_total, 1.0));
#ifndef USE_SH_LIGHTMAPS
vec4 accum = imageLoad(accum_light, ivec3(atlas_pos, params.atlas_slice));
accum.rgb += light_total;
imageStore(accum_light, ivec3(atlas_pos, params.atlas_slice), accum);
#endif
} else {
imageStore(bounce_accum, ivec3(atlas_pos, params.atlas_slice), vec4(light_total, active_rays));
}
#endif
#ifdef MODE_UNOCCLUDE
//texel_size = 0.5;
//compute tangents
vec4 position_alpha = imageLoad(position, ivec3(atlas_pos, params.atlas_slice));
if (position_alpha.a < 0.5) {
return;
}
vec3 vertex_pos = position_alpha.xyz;
vec4 normal_tsize = imageLoad(unocclude, ivec3(atlas_pos, params.atlas_slice));
vec3 face_normal = normal_tsize.xyz;
float texel_size = normal_tsize.w;
vec3 v0 = abs(face_normal.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(0.0, 1.0, 0.0);
vec3 tangent = normalize(cross(v0, face_normal));
vec3 bitangent = normalize(cross(tangent, face_normal));
vec3 base_pos = vertex_pos + face_normal * params.bias; //raise a bit
vec3 rays[4] = vec3[](tangent, bitangent, -tangent, -bitangent);
float min_d = 1e20;
for (int i = 0; i < 4; i++) {
vec3 ray_to = base_pos + rays[i] * texel_size;
float d;
vec3 norm;
if (trace_ray(base_pos, ray_to, d, norm) == RAY_BACK) {
if (d < min_d) {
vertex_pos = base_pos + rays[i] * d + norm * params.bias * 10.0; //this bias needs to be greater than the regular bias, because otherwise later, rays will go the other side when pointing back.
min_d = d;
}
}
}
position_alpha.xyz = vertex_pos;
imageStore(position, ivec3(atlas_pos, params.atlas_slice), position_alpha);
#endif
#ifdef MODE_LIGHT_PROBES
vec3 position = probe_positions.data[probe_index].xyz;
vec4 probe_sh_accum[9] = vec4[](
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0),
vec4(0.0));
uint noise = random_seed(ivec3(params.ray_from, probe_index, 49502741 /* some prime */));
for (uint i = params.ray_from; i < params.ray_to; i++) {
vec3 ray_dir = generate_hemisphere_uniform_direction(noise);
if (bool(i & 1)) {
//throw to both sides, so alternate them
ray_dir.z *= -1.0;
}
uint tidx;
vec3 barycentric;
vec3 light;
uint trace_result = trace_ray(position + ray_dir * params.bias, position + ray_dir * length(params.world_size), tidx, barycentric);
if (trace_result == RAY_FRONT) {
vec2 uv0 = vertices.data[triangles.data[tidx].indices.x].uv;
vec2 uv1 = vertices.data[triangles.data[tidx].indices.y].uv;
vec2 uv2 = vertices.data[triangles.data[tidx].indices.z].uv;
vec3 uvw = vec3(barycentric.x * uv0 + barycentric.y * uv1 + barycentric.z * uv2, float(triangles.data[tidx].slice));
light = textureLod(sampler2DArray(source_light, linear_sampler), uvw, 0.0).rgb;
light += textureLod(sampler2DArray(source_direct_light, linear_sampler), uvw, 0.0).rgb;
} else if (trace_result == RAY_MISS) {
//did not hit a triangle, reach out for the sky
vec3 sky_dir = normalize(mat3(params.env_transform) * ray_dir);
vec2 st = vec2(
atan(sky_dir.x, sky_dir.z),
acos(sky_dir.y));
if (st.x < 0.0)
st.x += PI * 2.0;
st /= vec2(PI * 2.0, PI);
light = textureLod(sampler2D(environment, linear_sampler), st, 0.0).rgb;
}
{
float c[9] = float[](
0.282095, //l0
0.488603 * ray_dir.y, //l1n1
0.488603 * ray_dir.z, //l1n0
0.488603 * ray_dir.x, //l1p1
1.092548 * ray_dir.x * ray_dir.y, //l2n2
1.092548 * ray_dir.y * ray_dir.z, //l2n1
//0.315392 * (ray_dir.x * ray_dir.x + ray_dir.y * ray_dir.y + 2.0 * ray_dir.z * ray_dir.z), //l20
0.315392 * (3.0 * ray_dir.z * ray_dir.z - 1.0), //l20
1.092548 * ray_dir.x * ray_dir.z, //l2p1
0.546274 * (ray_dir.x * ray_dir.x - ray_dir.y * ray_dir.y) //l2p2
);
for (uint j = 0; j < 9; j++) {
probe_sh_accum[j].rgb += light * c[j];
}
}
}
if (params.ray_from > 0) {
for (uint j = 0; j < 9; j++) { //accum from existing
probe_sh_accum[j] += light_probes.data[probe_index * 9 + j];
}
}
if (params.ray_to == params.ray_count) {
for (uint j = 0; j < 9; j++) { //accum from existing
probe_sh_accum[j] *= 4.0 / float(params.ray_count);
}
}
for (uint j = 0; j < 9; j++) { //accum from existing
light_probes.data[probe_index * 9 + j] = probe_sh_accum[j];
}
#endif
#ifdef MODE_DILATE
vec4 c = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0);
//sides first, as they are closer
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, -1), params.atlas_slice), 0);
//endpoints second
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 1), params.atlas_slice), 0);
//far sides third
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 0), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(0, -2), params.atlas_slice), 0);
//far-mid endpoints
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, -1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 1), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-1, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(1, 2), params.atlas_slice), 0);
//far endpoints
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(-2, 2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, -2), params.atlas_slice), 0);
c = c.a > 0.5 ? c : texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos + ivec2(2, 2), params.atlas_slice), 0);
imageStore(dest_light, ivec3(atlas_pos, params.atlas_slice), c);
#endif
#ifdef MODE_DENOISE
// Joint Non-local means (JNLM) denoiser.
//
// Based on YoctoImageDenoiser's JNLM implementation with corrections from "Nonlinearly Weighted First-order Regression for Denoising Monte Carlo Renderings".
//
// <https://github.com/ManuelPrandini/YoctoImageDenoiser/blob/06e19489dd64e47792acffde536393802ba48607/libs/yocto_extension/yocto_extension.cpp#L207>
// <https://benedikt-bitterli.me/nfor/nfor.pdf>
//
// MIT License
//
// Copyright (c) 2020 ManuelPrandini
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// Most of the constants below have been hand-picked to fit the common scenarios lightmaps
// are generated with, but they can be altered freely to experiment and achieve better results.
// Half the size of the patch window around each pixel that is weighted to compute the denoised pixel.
// A value of 1 represents a 3x3 window, a value of 2 a 5x5 window, etc.
const int HALF_PATCH_WINDOW = 4;
// Half the size of the search window around each pixel that is denoised and weighted to compute the denoised pixel.
const int HALF_SEARCH_WINDOW = 10;
// For all of the following sigma values, smaller values will give less weight to pixels that have a bigger distance
// in the feature being evaluated. Therefore, smaller values are likely to cause more noise to appear, but will also
// cause less features to be erased in the process.
// Controls how much the spatial distance of the pixels influences the denoising weight.
const float SIGMA_SPATIAL = denoise_params.spatial_bandwidth;
// Controls how much the light color distance of the pixels influences the denoising weight.
const float SIGMA_LIGHT = denoise_params.light_bandwidth;
// Controls how much the albedo color distance of the pixels influences the denoising weight.
const float SIGMA_ALBEDO = denoise_params.albedo_bandwidth;
// Controls how much the normal vector distance of the pixels influences the denoising weight.
const float SIGMA_NORMAL = denoise_params.normal_bandwidth;
// Strength of the filter. The original paper recommends values around 10 to 15 times the Sigma parameter.
const float FILTER_VALUE = denoise_params.filter_strength * SIGMA_LIGHT;
// Formula constants.
const int PATCH_WINDOW_DIMENSION = (HALF_PATCH_WINDOW * 2 + 1);
const int PATCH_WINDOW_DIMENSION_SQUARE = (PATCH_WINDOW_DIMENSION * PATCH_WINDOW_DIMENSION);
const float TWO_SIGMA_SPATIAL_SQUARE = 2.0f * SIGMA_SPATIAL * SIGMA_SPATIAL;
const float TWO_SIGMA_LIGHT_SQUARE = 2.0f * SIGMA_LIGHT * SIGMA_LIGHT;
const float TWO_SIGMA_ALBEDO_SQUARE = 2.0f * SIGMA_ALBEDO * SIGMA_ALBEDO;
const float TWO_SIGMA_NORMAL_SQUARE = 2.0f * SIGMA_NORMAL * SIGMA_NORMAL;
const float FILTER_SQUARE_TWO_SIGMA_LIGHT_SQUARE = FILTER_VALUE * FILTER_VALUE * TWO_SIGMA_LIGHT_SQUARE;
const float EPSILON = 1e-6f;
#ifdef USE_SH_LIGHTMAPS
const uint slice_count = 4;
const uint slice_base = params.atlas_slice * slice_count;
#else
const uint slice_count = 1;
const uint slice_base = params.atlas_slice;
#endif
for (uint i = 0; i < slice_count; i++) {
uint lightmap_slice = slice_base + i;
vec3 denoised_rgb = vec3(0.0f);
vec4 input_light = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(atlas_pos, lightmap_slice), 0);
vec3 input_albedo = texelFetch(sampler2DArray(albedo_tex, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).rgb;
vec3 input_normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(atlas_pos, params.atlas_slice), 0).xyz;
if (length(input_normal) > EPSILON) {
// Compute the denoised pixel if the normal is valid.
float sum_weights = 0.0f;
vec3 input_rgb = input_light.rgb;
for (int search_y = -HALF_SEARCH_WINDOW; search_y <= HALF_SEARCH_WINDOW; search_y++) {
for (int search_x = -HALF_SEARCH_WINDOW; search_x <= HALF_SEARCH_WINDOW; search_x++) {
ivec2 search_pos = atlas_pos + ivec2(search_x, search_y);
vec3 search_rgb = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(search_pos, lightmap_slice), 0).rgb;
vec3 search_albedo = texelFetch(sampler2DArray(albedo_tex, linear_sampler), ivec3(search_pos, params.atlas_slice), 0).rgb;
vec3 search_normal = texelFetch(sampler2DArray(source_normal, linear_sampler), ivec3(search_pos, params.atlas_slice), 0).xyz;
float patch_square_dist = 0.0f;
for (int offset_y = -HALF_PATCH_WINDOW; offset_y <= HALF_PATCH_WINDOW; offset_y++) {
for (int offset_x = -HALF_PATCH_WINDOW; offset_x <= HALF_PATCH_WINDOW; offset_x++) {
ivec2 offset_input_pos = atlas_pos + ivec2(offset_x, offset_y);
ivec2 offset_search_pos = search_pos + ivec2(offset_x, offset_y);
vec3 offset_input_rgb = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(offset_input_pos, lightmap_slice), 0).rgb;
vec3 offset_search_rgb = texelFetch(sampler2DArray(source_light, linear_sampler), ivec3(offset_search_pos, lightmap_slice), 0).rgb;
vec3 offset_delta_rgb = offset_input_rgb - offset_search_rgb;
patch_square_dist += dot(offset_delta_rgb, offset_delta_rgb) - TWO_SIGMA_LIGHT_SQUARE;
}
}
patch_square_dist = max(0.0f, patch_square_dist / (3.0f * PATCH_WINDOW_DIMENSION_SQUARE));
float weight = 1.0f;
// Ignore weight if search position is out of bounds.
weight *= step(0, search_pos.x) * step(search_pos.x, params.atlas_size.x - 1);
weight *= step(0, search_pos.y) * step(search_pos.y, params.atlas_size.y - 1);
// Ignore weight if normal is zero length.
weight *= step(EPSILON, length(search_normal));
// Weight with pixel distance.
vec2 pixel_delta = vec2(search_x, search_y);
float pixel_square_dist = dot(pixel_delta, pixel_delta);
weight *= exp(-pixel_square_dist / TWO_SIGMA_SPATIAL_SQUARE);
// Weight with patch.
weight *= exp(-patch_square_dist / FILTER_SQUARE_TWO_SIGMA_LIGHT_SQUARE);
// Weight with albedo.
vec3 albedo_delta = input_albedo - search_albedo;
float albedo_square_dist = dot(albedo_delta, albedo_delta);
weight *= exp(-albedo_square_dist / TWO_SIGMA_ALBEDO_SQUARE);
// Weight with normal.
vec3 normal_delta = input_normal - search_normal;
float normal_square_dist = dot(normal_delta, normal_delta);
weight *= exp(-normal_square_dist / TWO_SIGMA_NORMAL_SQUARE);
denoised_rgb += weight * search_rgb;
sum_weights += weight;
}
}
denoised_rgb /= sum_weights;
} else {
// Ignore pixels where the normal is empty, just copy the light color.
denoised_rgb = input_light.rgb;
}
imageStore(dest_light, ivec3(atlas_pos, lightmap_slice), vec4(denoised_rgb, input_light.a));
}
#endif
}