godot/servers/rendering/renderer_rd/shaders/environment/gi.glsl
Bastiaan Olij d139131aab Adding Variable Rate Shading support to Godot
Improve GI renderer and add VRS support
Implement render device has_feature and move subgroup settings to limit_get
2022-07-17 15:42:24 +10:00

765 lines
24 KiB
GLSL

#[compute]
#version 450
#VERSION_DEFINES
layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
#define M_PI 3.141592
/* Specialization Constants (Toggles) */
layout(constant_id = 0) const bool sc_half_res = false;
layout(constant_id = 1) const bool sc_use_full_projection_matrix = false;
layout(constant_id = 2) const bool sc_use_vrs = false;
#define SDFGI_MAX_CASCADES 8
//set 0 for SDFGI and render buffers
layout(set = 0, binding = 1) uniform texture3D sdf_cascades[SDFGI_MAX_CASCADES];
layout(set = 0, binding = 2) uniform texture3D light_cascades[SDFGI_MAX_CASCADES];
layout(set = 0, binding = 3) uniform texture3D aniso0_cascades[SDFGI_MAX_CASCADES];
layout(set = 0, binding = 4) uniform texture3D aniso1_cascades[SDFGI_MAX_CASCADES];
layout(set = 0, binding = 5) uniform texture3D occlusion_texture;
layout(set = 0, binding = 6) uniform sampler linear_sampler;
layout(set = 0, binding = 7) uniform sampler linear_sampler_with_mipmaps;
struct ProbeCascadeData {
vec3 position;
float to_probe;
ivec3 probe_world_offset;
float to_cell; // 1/bounds * grid_size
};
layout(rgba16f, set = 0, binding = 9) uniform restrict writeonly image2D ambient_buffer;
layout(rgba16f, set = 0, binding = 10) uniform restrict writeonly image2D reflection_buffer;
layout(set = 0, binding = 11) uniform texture2DArray lightprobe_texture;
layout(set = 0, binding = 12) uniform texture2D depth_buffer;
layout(set = 0, binding = 13) uniform texture2D normal_roughness_buffer;
layout(set = 0, binding = 14) uniform utexture2D voxel_gi_buffer;
layout(set = 0, binding = 15, std140) uniform SDFGI {
vec3 grid_size;
uint max_cascades;
bool use_occlusion;
int probe_axis_size;
float probe_to_uvw;
float normal_bias;
vec3 lightprobe_tex_pixel_size;
float energy;
vec3 lightprobe_uv_offset;
float y_mult;
vec3 occlusion_clamp;
uint pad3;
vec3 occlusion_renormalize;
uint pad4;
vec3 cascade_probe_size;
uint pad5;
ProbeCascadeData cascades[SDFGI_MAX_CASCADES];
}
sdfgi;
#define MAX_VOXEL_GI_INSTANCES 8
struct VoxelGIData {
mat4 xform; // 64 - 64
vec3 bounds; // 12 - 76
float dynamic_range; // 4 - 80
float bias; // 4 - 84
float normal_bias; // 4 - 88
bool blend_ambient; // 4 - 92
uint mipmaps; // 4 - 96
};
layout(set = 0, binding = 16, std140) uniform VoxelGIs {
VoxelGIData data[MAX_VOXEL_GI_INSTANCES];
}
voxel_gi_instances;
layout(set = 0, binding = 17) uniform texture3D voxel_gi_textures[MAX_VOXEL_GI_INSTANCES];
layout(set = 0, binding = 18, std140) uniform SceneData {
mat4x4 inv_projection[2];
mat4x4 cam_transform;
vec4 eye_offset[2];
ivec2 screen_size;
float pad1;
float pad2;
}
scene_data;
layout(r8ui, set = 0, binding = 19) uniform restrict readonly uimage2D vrs_buffer;
layout(push_constant, std430) uniform Params {
uint max_voxel_gi_instances;
bool high_quality_vct;
bool orthogonal;
uint view_index;
vec4 proj_info;
float z_near;
float z_far;
float pad2;
float pad3;
}
params;
vec2 octahedron_wrap(vec2 v) {
vec2 signVal;
signVal.x = v.x >= 0.0 ? 1.0 : -1.0;
signVal.y = v.y >= 0.0 ? 1.0 : -1.0;
return (1.0 - abs(v.yx)) * signVal;
}
vec2 octahedron_encode(vec3 n) {
// https://twitter.com/Stubbesaurus/status/937994790553227264
n /= (abs(n.x) + abs(n.y) + abs(n.z));
n.xy = n.z >= 0.0 ? n.xy : octahedron_wrap(n.xy);
n.xy = n.xy * 0.5 + 0.5;
return n.xy;
}
vec4 blend_color(vec4 src, vec4 dst) {
vec4 res;
float sa = 1.0 - src.a;
res.a = dst.a * sa + src.a;
if (res.a == 0.0) {
res.rgb = vec3(0);
} else {
res.rgb = (dst.rgb * dst.a * sa + src.rgb * src.a) / res.a;
}
return res;
}
vec3 reconstruct_position(ivec2 screen_pos) {
if (sc_use_full_projection_matrix) {
vec4 pos;
pos.xy = (2.0 * vec2(screen_pos) / vec2(scene_data.screen_size)) - 1.0;
pos.z = texelFetch(sampler2D(depth_buffer, linear_sampler), screen_pos, 0).r * 2.0 - 1.0;
pos.w = 1.0;
pos = scene_data.inv_projection[params.view_index] * pos;
return pos.xyz / pos.w;
} else {
vec3 pos;
pos.z = texelFetch(sampler2D(depth_buffer, linear_sampler), screen_pos, 0).r;
pos.z = pos.z * 2.0 - 1.0;
if (params.orthogonal) {
pos.z = ((pos.z + (params.z_far + params.z_near) / (params.z_far - params.z_near)) * (params.z_far - params.z_near)) / 2.0;
} else {
pos.z = 2.0 * params.z_near * params.z_far / (params.z_far + params.z_near - pos.z * (params.z_far - params.z_near));
}
pos.z = -pos.z;
pos.xy = vec2(screen_pos) * params.proj_info.xy + params.proj_info.zw;
if (!params.orthogonal) {
pos.xy *= pos.z;
}
return pos;
}
}
void sdfvoxel_gi_process(uint cascade, vec3 cascade_pos, vec3 cam_pos, vec3 cam_normal, vec3 cam_specular_normal, float roughness, out vec3 diffuse_light, out vec3 specular_light) {
cascade_pos += cam_normal * sdfgi.normal_bias;
vec3 base_pos = floor(cascade_pos);
//cascade_pos += mix(vec3(0.0),vec3(0.01),lessThan(abs(cascade_pos-base_pos),vec3(0.01))) * cam_normal;
ivec3 probe_base_pos = ivec3(base_pos);
vec4 diffuse_accum = vec4(0.0);
vec3 specular_accum;
ivec3 tex_pos = ivec3(probe_base_pos.xy, int(cascade));
tex_pos.x += probe_base_pos.z * sdfgi.probe_axis_size;
tex_pos.xy = tex_pos.xy * (SDFGI_OCT_SIZE + 2) + ivec2(1);
vec3 diffuse_posf = (vec3(tex_pos) + vec3(octahedron_encode(cam_normal) * float(SDFGI_OCT_SIZE), 0.0)) * sdfgi.lightprobe_tex_pixel_size;
vec3 specular_posf = (vec3(tex_pos) + vec3(octahedron_encode(cam_specular_normal) * float(SDFGI_OCT_SIZE), 0.0)) * sdfgi.lightprobe_tex_pixel_size;
specular_accum = vec3(0.0);
vec4 light_accum = vec4(0.0);
float weight_accum = 0.0;
for (uint j = 0; j < 8; j++) {
ivec3 offset = (ivec3(j) >> ivec3(0, 1, 2)) & ivec3(1, 1, 1);
ivec3 probe_posi = probe_base_pos;
probe_posi += offset;
// Compute weight
vec3 probe_pos = vec3(probe_posi);
vec3 probe_to_pos = cascade_pos - probe_pos;
vec3 probe_dir = normalize(-probe_to_pos);
vec3 trilinear = vec3(1.0) - abs(probe_to_pos);
float weight = trilinear.x * trilinear.y * trilinear.z * max(0.005, dot(cam_normal, probe_dir));
// Compute lightprobe occlusion
if (sdfgi.use_occlusion) {
ivec3 occ_indexv = abs((sdfgi.cascades[cascade].probe_world_offset + probe_posi) & ivec3(1, 1, 1)) * ivec3(1, 2, 4);
vec4 occ_mask = mix(vec4(0.0), vec4(1.0), equal(ivec4(occ_indexv.x | occ_indexv.y), ivec4(0, 1, 2, 3)));
vec3 occ_pos = clamp(cascade_pos, probe_pos - sdfgi.occlusion_clamp, probe_pos + sdfgi.occlusion_clamp) * sdfgi.probe_to_uvw;
occ_pos.z += float(cascade);
if (occ_indexv.z != 0) { //z bit is on, means index is >=4, so make it switch to the other half of textures
occ_pos.x += 1.0;
}
occ_pos *= sdfgi.occlusion_renormalize;
float occlusion = dot(textureLod(sampler3D(occlusion_texture, linear_sampler), occ_pos, 0.0), occ_mask);
weight *= max(occlusion, 0.01);
}
// Compute lightprobe texture position
vec3 diffuse;
vec3 pos_uvw = diffuse_posf;
pos_uvw.xy += vec2(offset.xy) * sdfgi.lightprobe_uv_offset.xy;
pos_uvw.x += float(offset.z) * sdfgi.lightprobe_uv_offset.z;
diffuse = textureLod(sampler2DArray(lightprobe_texture, linear_sampler), pos_uvw, 0.0).rgb;
diffuse_accum += vec4(diffuse * weight, weight);
{
vec3 specular = vec3(0.0);
vec3 pos_uvw = specular_posf;
pos_uvw.xy += vec2(offset.xy) * sdfgi.lightprobe_uv_offset.xy;
pos_uvw.x += float(offset.z) * sdfgi.lightprobe_uv_offset.z;
if (roughness < 0.99) {
specular = textureLod(sampler2DArray(lightprobe_texture, linear_sampler), pos_uvw + vec3(0, 0, float(sdfgi.max_cascades)), 0.0).rgb;
}
if (roughness > 0.2) {
specular = mix(specular, textureLod(sampler2DArray(lightprobe_texture, linear_sampler), pos_uvw, 0.0).rgb, (roughness - 0.2) * 1.25);
}
specular_accum += specular * weight;
}
}
if (diffuse_accum.a > 0.0) {
diffuse_accum.rgb /= diffuse_accum.a;
}
diffuse_light = diffuse_accum.rgb;
if (diffuse_accum.a > 0.0) {
specular_accum /= diffuse_accum.a;
}
specular_light = specular_accum;
}
void sdfgi_process(vec3 vertex, vec3 normal, vec3 reflection, float roughness, out vec4 ambient_light, out vec4 reflection_light) {
//make vertex orientation the world one, but still align to camera
vertex.y *= sdfgi.y_mult;
normal.y *= sdfgi.y_mult;
reflection.y *= sdfgi.y_mult;
//renormalize
normal = normalize(normal);
reflection = normalize(reflection);
vec3 cam_pos = vertex;
vec3 cam_normal = normal;
vec4 light_accum = vec4(0.0);
float weight_accum = 0.0;
vec4 light_blend_accum = vec4(0.0);
float weight_blend_accum = 0.0;
float blend = -1.0;
// helper constants, compute once
uint cascade = 0xFFFFFFFF;
vec3 cascade_pos;
vec3 cascade_normal;
for (uint i = 0; i < sdfgi.max_cascades; i++) {
cascade_pos = (cam_pos - sdfgi.cascades[i].position) * sdfgi.cascades[i].to_probe;
if (any(lessThan(cascade_pos, vec3(0.0))) || any(greaterThanEqual(cascade_pos, sdfgi.cascade_probe_size))) {
continue; //skip cascade
}
cascade = i;
break;
}
if (cascade < SDFGI_MAX_CASCADES) {
ambient_light = vec4(0, 0, 0, 1);
reflection_light = vec4(0, 0, 0, 1);
float blend;
vec3 diffuse, specular;
sdfvoxel_gi_process(cascade, cascade_pos, cam_pos, cam_normal, reflection, roughness, diffuse, specular);
{
//process blend
float blend_from = (float(sdfgi.probe_axis_size - 1) / 2.0) - 2.5;
float blend_to = blend_from + 2.0;
vec3 inner_pos = cam_pos * sdfgi.cascades[cascade].to_probe;
float len = length(inner_pos);
inner_pos = abs(normalize(inner_pos));
len *= max(inner_pos.x, max(inner_pos.y, inner_pos.z));
if (len >= blend_from) {
blend = smoothstep(blend_from, blend_to, len);
} else {
blend = 0.0;
}
}
if (blend > 0.0) {
//blend
if (cascade == sdfgi.max_cascades - 1) {
ambient_light.a = 1.0 - blend;
reflection_light.a = 1.0 - blend;
} else {
vec3 diffuse2, specular2;
cascade_pos = (cam_pos - sdfgi.cascades[cascade + 1].position) * sdfgi.cascades[cascade + 1].to_probe;
sdfvoxel_gi_process(cascade + 1, cascade_pos, cam_pos, cam_normal, reflection, roughness, diffuse2, specular2);
diffuse = mix(diffuse, diffuse2, blend);
specular = mix(specular, specular2, blend);
}
}
ambient_light.rgb = diffuse;
if (roughness < 0.2) {
vec3 pos_to_uvw = 1.0 / sdfgi.grid_size;
vec4 light_accum = vec4(0.0);
float blend_size = (sdfgi.grid_size.x / float(sdfgi.probe_axis_size - 1)) * 0.5;
float radius_sizes[SDFGI_MAX_CASCADES];
cascade = 0xFFFF;
float base_distance = length(cam_pos);
for (uint i = 0; i < sdfgi.max_cascades; i++) {
radius_sizes[i] = (1.0 / sdfgi.cascades[i].to_cell) * (sdfgi.grid_size.x * 0.5 - blend_size);
if (cascade == 0xFFFF && base_distance < radius_sizes[i]) {
cascade = i;
}
}
cascade = min(cascade, sdfgi.max_cascades - 1);
float max_distance = radius_sizes[sdfgi.max_cascades - 1];
vec3 ray_pos = cam_pos;
vec3 ray_dir = reflection;
{
float prev_radius = cascade > 0 ? radius_sizes[cascade - 1] : 0.0;
float base_blend = (base_distance - prev_radius) / (radius_sizes[cascade] - prev_radius);
float bias = (1.0 + base_blend) * 1.1;
vec3 abs_ray_dir = abs(ray_dir);
//ray_pos += ray_dir * (bias / sdfgi.cascades[cascade].to_cell); //bias to avoid self occlusion
ray_pos += (ray_dir * 1.0 / max(abs_ray_dir.x, max(abs_ray_dir.y, abs_ray_dir.z)) + cam_normal * 1.4) * bias / sdfgi.cascades[cascade].to_cell;
}
float softness = 0.2 + min(1.0, roughness * 5.0) * 4.0; //approximation to roughness so it does not seem like a hard fade
uint i = 0;
bool found = false;
while (true) {
if (length(ray_pos) >= max_distance || light_accum.a > 0.99) {
break;
}
if (!found && i >= cascade && length(ray_pos) < radius_sizes[i]) {
uint next_i = min(i + 1, sdfgi.max_cascades - 1);
cascade = max(i, cascade); //never go down
vec3 pos = ray_pos - sdfgi.cascades[i].position;
pos *= sdfgi.cascades[i].to_cell * pos_to_uvw;
float fdistance = textureLod(sampler3D(sdf_cascades[i], linear_sampler), pos, 0.0).r * 255.0 - 1.1;
vec4 hit_light = vec4(0.0);
if (fdistance < softness) {
hit_light.rgb = textureLod(sampler3D(light_cascades[i], linear_sampler), pos, 0.0).rgb;
hit_light.rgb *= 0.5; //approximation given value read is actually meant for anisotropy
hit_light.a = clamp(1.0 - (fdistance / softness), 0.0, 1.0);
hit_light.rgb *= hit_light.a;
}
fdistance /= sdfgi.cascades[i].to_cell;
if (i < (sdfgi.max_cascades - 1)) {
pos = ray_pos - sdfgi.cascades[next_i].position;
pos *= sdfgi.cascades[next_i].to_cell * pos_to_uvw;
float fdistance2 = textureLod(sampler3D(sdf_cascades[next_i], linear_sampler), pos, 0.0).r * 255.0 - 1.1;
vec4 hit_light2 = vec4(0.0);
if (fdistance2 < softness) {
hit_light2.rgb = textureLod(sampler3D(light_cascades[next_i], linear_sampler), pos, 0.0).rgb;
hit_light2.rgb *= 0.5; //approximation given value read is actually meant for anisotropy
hit_light2.a = clamp(1.0 - (fdistance2 / softness), 0.0, 1.0);
hit_light2.rgb *= hit_light2.a;
}
float prev_radius = i == 0 ? 0.0 : radius_sizes[max(0, i - 1)];
float blend = clamp((length(ray_pos) - prev_radius) / (radius_sizes[i] - prev_radius), 0.0, 1.0);
fdistance2 /= sdfgi.cascades[next_i].to_cell;
hit_light = mix(hit_light, hit_light2, blend);
fdistance = mix(fdistance, fdistance2, blend);
}
light_accum += hit_light;
ray_pos += ray_dir * fdistance;
found = true;
}
i++;
if (i == sdfgi.max_cascades) {
i = 0;
found = false;
}
}
vec3 light = light_accum.rgb / max(light_accum.a, 0.00001);
float alpha = min(1.0, light_accum.a);
float b = min(1.0, roughness * 5.0);
float sa = 1.0 - b;
reflection_light.a = alpha * sa + b;
if (reflection_light.a == 0) {
specular = vec3(0.0);
} else {
specular = (light * alpha * sa + specular * b) / reflection_light.a;
}
}
reflection_light.rgb = specular;
ambient_light.rgb *= sdfgi.energy;
reflection_light.rgb *= sdfgi.energy;
} else {
ambient_light = vec4(0);
reflection_light = vec4(0);
}
}
//standard voxel cone trace
vec4 voxel_cone_trace(texture3D probe, vec3 cell_size, vec3 pos, vec3 direction, float tan_half_angle, float max_distance, float p_bias) {
float dist = p_bias;
vec4 color = vec4(0.0);
while (dist < max_distance && color.a < 0.95) {
float diameter = max(1.0, 2.0 * tan_half_angle * dist);
vec3 uvw_pos = (pos + dist * direction) * cell_size;
float half_diameter = diameter * 0.5;
//check if outside, then break
if (any(greaterThan(abs(uvw_pos - 0.5), vec3(0.5f + half_diameter * cell_size)))) {
break;
}
vec4 scolor = textureLod(sampler3D(probe, linear_sampler_with_mipmaps), uvw_pos, log2(diameter));
float a = (1.0 - color.a);
color += a * scolor;
dist += half_diameter;
}
return color;
}
vec4 voxel_cone_trace_45_degrees(texture3D probe, vec3 cell_size, vec3 pos, vec3 direction, float max_distance, float p_bias) {
float dist = p_bias;
vec4 color = vec4(0.0);
float radius = max(0.5, dist);
float lod_level = log2(radius * 2.0);
while (dist < max_distance && color.a < 0.95) {
vec3 uvw_pos = (pos + dist * direction) * cell_size;
//check if outside, then break
if (any(greaterThan(abs(uvw_pos - 0.5), vec3(0.5f + radius * cell_size)))) {
break;
}
vec4 scolor = textureLod(sampler3D(probe, linear_sampler_with_mipmaps), uvw_pos, lod_level);
lod_level += 1.0;
float a = (1.0 - color.a);
scolor *= a;
color += scolor;
dist += radius;
radius = max(0.5, dist);
}
return color;
}
void voxel_gi_compute(uint index, vec3 position, vec3 normal, vec3 ref_vec, mat3 normal_xform, float roughness, inout vec4 out_spec, inout vec4 out_diff, inout float out_blend) {
position = (voxel_gi_instances.data[index].xform * vec4(position, 1.0)).xyz;
ref_vec = normalize((voxel_gi_instances.data[index].xform * vec4(ref_vec, 0.0)).xyz);
normal = normalize((voxel_gi_instances.data[index].xform * vec4(normal, 0.0)).xyz);
position += normal * voxel_gi_instances.data[index].normal_bias;
//this causes corrupted pixels, i have no idea why..
if (any(bvec2(any(lessThan(position, vec3(0.0))), any(greaterThan(position, voxel_gi_instances.data[index].bounds))))) {
return;
}
mat3 dir_xform = mat3(voxel_gi_instances.data[index].xform) * normal_xform;
vec3 blendv = abs(position / voxel_gi_instances.data[index].bounds * 2.0 - 1.0);
float blend = clamp(1.0 - max(blendv.x, max(blendv.y, blendv.z)), 0.0, 1.0);
//float blend=1.0;
float max_distance = length(voxel_gi_instances.data[index].bounds);
vec3 cell_size = 1.0 / voxel_gi_instances.data[index].bounds;
//irradiance
vec4 light = vec4(0.0);
if (params.high_quality_vct) {
const uint cone_dir_count = 6;
vec3 cone_dirs[cone_dir_count] = vec3[](
vec3(0.0, 0.0, 1.0),
vec3(0.866025, 0.0, 0.5),
vec3(0.267617, 0.823639, 0.5),
vec3(-0.700629, 0.509037, 0.5),
vec3(-0.700629, -0.509037, 0.5),
vec3(0.267617, -0.823639, 0.5));
float cone_weights[cone_dir_count] = float[](0.25, 0.15, 0.15, 0.15, 0.15, 0.15);
float cone_angle_tan = 0.577;
for (uint i = 0; i < cone_dir_count; i++) {
vec3 dir = normalize(dir_xform * cone_dirs[i]);
light += cone_weights[i] * voxel_cone_trace(voxel_gi_textures[index], cell_size, position, dir, cone_angle_tan, max_distance, voxel_gi_instances.data[index].bias);
}
} else {
const uint cone_dir_count = 4;
vec3 cone_dirs[cone_dir_count] = vec3[](
vec3(0.707107, 0.0, 0.707107),
vec3(0.0, 0.707107, 0.707107),
vec3(-0.707107, 0.0, 0.707107),
vec3(0.0, -0.707107, 0.707107));
float cone_weights[cone_dir_count] = float[](0.25, 0.25, 0.25, 0.25);
for (int i = 0; i < cone_dir_count; i++) {
vec3 dir = normalize(dir_xform * cone_dirs[i]);
light += cone_weights[i] * voxel_cone_trace_45_degrees(voxel_gi_textures[index], cell_size, position, dir, max_distance, voxel_gi_instances.data[index].bias);
}
}
light.rgb *= voxel_gi_instances.data[index].dynamic_range;
if (!voxel_gi_instances.data[index].blend_ambient) {
light.a = 1.0;
}
out_diff += light * blend;
//radiance
vec4 irr_light = voxel_cone_trace(voxel_gi_textures[index], cell_size, position, ref_vec, tan(roughness * 0.5 * M_PI * 0.99), max_distance, voxel_gi_instances.data[index].bias);
irr_light.rgb *= voxel_gi_instances.data[index].dynamic_range;
if (!voxel_gi_instances.data[index].blend_ambient) {
irr_light.a = 1.0;
}
out_spec += irr_light * blend;
out_blend += blend;
}
vec4 fetch_normal_and_roughness(ivec2 pos) {
vec4 normal_roughness = texelFetch(sampler2D(normal_roughness_buffer, linear_sampler), pos, 0);
normal_roughness.xyz = normalize(normal_roughness.xyz * 2.0 - 1.0);
return normal_roughness;
}
void process_gi(ivec2 pos, vec3 vertex, inout vec4 ambient_light, inout vec4 reflection_light) {
vec4 normal_roughness = fetch_normal_and_roughness(pos);
vec3 normal = normal_roughness.xyz;
if (normal.length() > 0.5) {
//valid normal, can do GI
float roughness = normal_roughness.w;
vec3 view = -normalize(mat3(scene_data.cam_transform) * (vertex - scene_data.eye_offset[gl_GlobalInvocationID.z].xyz));
vertex = mat3(scene_data.cam_transform) * vertex;
normal = normalize(mat3(scene_data.cam_transform) * normal);
vec3 reflection = normalize(reflect(-view, normal));
#ifdef USE_SDFGI
sdfgi_process(vertex, normal, reflection, roughness, ambient_light, reflection_light);
#endif
#ifdef USE_VOXEL_GI_INSTANCES
{
uvec2 voxel_gi_tex = texelFetch(usampler2D(voxel_gi_buffer, linear_sampler), pos, 0).rg;
roughness *= roughness;
//find arbitrary tangent and bitangent, then build a matrix
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);
vec4 amb_accum = vec4(0.0);
vec4 spec_accum = vec4(0.0);
float blend_accum = 0.0;
for (uint i = 0; i < params.max_voxel_gi_instances; i++) {
if (any(equal(uvec2(i), voxel_gi_tex))) {
voxel_gi_compute(i, vertex, normal, reflection, normal_mat, roughness, spec_accum, amb_accum, blend_accum);
}
}
if (blend_accum > 0.0) {
amb_accum /= blend_accum;
spec_accum /= blend_accum;
}
#ifdef USE_SDFGI
reflection_light = blend_color(spec_accum, reflection_light);
ambient_light = blend_color(amb_accum, ambient_light);
#else
reflection_light = spec_accum;
ambient_light = amb_accum;
#endif
}
#endif
}
}
void main() {
ivec2 pos = ivec2(gl_GlobalInvocationID.xy);
uint vrs_x, vrs_y;
if (sc_use_vrs) {
ivec2 vrs_pos;
// Currenty we use a 16x16 texel, possibly some day make this configurable.
if (sc_half_res) {
vrs_pos = pos >> 3;
} else {
vrs_pos = pos >> 4;
}
uint vrs_texel = imageLoad(vrs_buffer, vrs_pos).r;
// note, valid values for vrs_x and vrs_y are 1, 2 and 4.
vrs_x = 1 << ((vrs_texel >> 2) & 3);
vrs_y = 1 << (vrs_texel & 3);
if (mod(pos.x, vrs_x) != 0) {
return;
}
if (mod(pos.y, vrs_y) != 0) {
return;
}
}
if (sc_half_res) {
pos <<= 1;
}
if (any(greaterThanEqual(pos, scene_data.screen_size))) { //too large, do nothing
return;
}
vec4 ambient_light = vec4(0.0);
vec4 reflection_light = vec4(0.0);
vec3 vertex = reconstruct_position(pos);
vertex.y = -vertex.y;
process_gi(pos, vertex, ambient_light, reflection_light);
if (sc_half_res) {
pos >>= 1;
}
imageStore(ambient_buffer, pos, ambient_light);
imageStore(reflection_buffer, pos, reflection_light);
if (sc_use_vrs) {
if (vrs_x > 1) {
imageStore(ambient_buffer, pos + ivec2(1, 0), ambient_light);
imageStore(reflection_buffer, pos + ivec2(1, 0), reflection_light);
}
if (vrs_x > 2) {
imageStore(ambient_buffer, pos + ivec2(2, 0), ambient_light);
imageStore(reflection_buffer, pos + ivec2(2, 0), reflection_light);
imageStore(ambient_buffer, pos + ivec2(3, 0), ambient_light);
imageStore(reflection_buffer, pos + ivec2(3, 0), reflection_light);
}
if (vrs_y > 1) {
imageStore(ambient_buffer, pos + ivec2(0, 1), ambient_light);
imageStore(reflection_buffer, pos + ivec2(0, 1), reflection_light);
}
if (vrs_y > 1 && vrs_x > 1) {
imageStore(ambient_buffer, pos + ivec2(1, 1), ambient_light);
imageStore(reflection_buffer, pos + ivec2(1, 1), reflection_light);
}
if (vrs_y > 1 && vrs_x > 2) {
imageStore(ambient_buffer, pos + ivec2(2, 1), ambient_light);
imageStore(reflection_buffer, pos + ivec2(2, 1), reflection_light);
imageStore(ambient_buffer, pos + ivec2(3, 1), ambient_light);
imageStore(reflection_buffer, pos + ivec2(3, 1), reflection_light);
}
if (vrs_y > 2) {
imageStore(ambient_buffer, pos + ivec2(0, 2), ambient_light);
imageStore(reflection_buffer, pos + ivec2(0, 2), reflection_light);
imageStore(ambient_buffer, pos + ivec2(0, 3), ambient_light);
imageStore(reflection_buffer, pos + ivec2(0, 3), reflection_light);
}
if (vrs_y > 2 && vrs_x > 1) {
imageStore(ambient_buffer, pos + ivec2(1, 2), ambient_light);
imageStore(reflection_buffer, pos + ivec2(1, 2), reflection_light);
imageStore(ambient_buffer, pos + ivec2(1, 3), ambient_light);
imageStore(reflection_buffer, pos + ivec2(1, 3), reflection_light);
}
if (vrs_y > 2 && vrs_x > 2) {
imageStore(ambient_buffer, pos + ivec2(2, 2), ambient_light);
imageStore(reflection_buffer, pos + ivec2(2, 2), reflection_light);
imageStore(ambient_buffer, pos + ivec2(2, 3), ambient_light);
imageStore(reflection_buffer, pos + ivec2(2, 3), reflection_light);
imageStore(ambient_buffer, pos + ivec2(3, 2), ambient_light);
imageStore(reflection_buffer, pos + ivec2(3, 2), reflection_light);
imageStore(ambient_buffer, pos + ivec2(3, 3), ambient_light);
imageStore(reflection_buffer, pos + ivec2(3, 3), reflection_light);
}
}
}