484 lines
13 KiB
GLSL
484 lines
13 KiB
GLSL
#[compute]
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#version 450
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VERSION_DEFINES
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layout(local_size_x = 64, local_size_y = 1, local_size_z = 1) in;
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#define MAX_CASCADES 8
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layout(set = 0, binding = 1) uniform texture3D sdf_cascades[MAX_CASCADES];
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layout(set = 0, binding = 2) uniform sampler linear_sampler;
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layout(set = 0, binding = 3, std430) restrict readonly buffer DispatchData {
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uint x;
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uint y;
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uint z;
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uint total_count;
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}
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dispatch_data;
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struct ProcessVoxel {
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uint position; //xyz 7 bit packed, extra 11 bits for neigbours
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uint albedo; //rgb bits 0-15 albedo, bits 16-21 are normal bits (set if geometry exists toward that side), extra 11 bits for neibhbours
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uint light; //rgbe8985 encoded total saved light, extra 2 bits for neighbours
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uint light_aniso; //55555 light anisotropy, extra 2 bits for neighbours
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//total neighbours: 26
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};
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#ifdef MODE_PROCESS_STATIC
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layout(set = 0, binding = 4, std430) restrict buffer ProcessVoxels {
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#else
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layout(set = 0, binding = 4, std430) restrict buffer readonly ProcessVoxels {
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#endif
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ProcessVoxel data[];
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}
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process_voxels;
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layout(r32ui, set = 0, binding = 5) uniform restrict uimage3D dst_light;
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layout(rgba8, set = 0, binding = 6) uniform restrict image3D dst_aniso0;
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layout(rg8, set = 0, binding = 7) uniform restrict image3D dst_aniso1;
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struct CascadeData {
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vec3 offset; //offset of (0,0,0) in world coordinates
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float to_cell; // 1/bounds * grid_size
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ivec3 probe_world_offset;
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uint pad;
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};
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layout(set = 0, binding = 8, std140) uniform Cascades {
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CascadeData data[MAX_CASCADES];
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}
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cascades;
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#define LIGHT_TYPE_DIRECTIONAL 0
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#define LIGHT_TYPE_OMNI 1
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#define LIGHT_TYPE_SPOT 2
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struct Light {
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vec3 color;
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float energy;
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vec3 direction;
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bool has_shadow;
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vec3 position;
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float attenuation;
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uint type;
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float spot_angle;
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float spot_attenuation;
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float radius;
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vec4 shadow_color;
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};
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layout(set = 0, binding = 9, std140) buffer restrict readonly Lights {
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Light data[];
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}
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lights;
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layout(set = 0, binding = 10) uniform texture2DArray lightprobe_texture;
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layout(push_constant, binding = 0, std430) uniform Params {
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vec3 grid_size;
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uint max_cascades;
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uint cascade;
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uint light_count;
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uint process_offset;
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uint process_increment;
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int probe_axis_size;
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bool multibounce;
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float y_mult;
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uint pad;
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}
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params;
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vec2 octahedron_wrap(vec2 v) {
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vec2 signVal;
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signVal.x = v.x >= 0.0 ? 1.0 : -1.0;
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signVal.y = v.y >= 0.0 ? 1.0 : -1.0;
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return (1.0 - abs(v.yx)) * signVal;
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}
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vec2 octahedron_encode(vec3 n) {
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// https://twitter.com/Stubbesaurus/status/937994790553227264
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n /= (abs(n.x) + abs(n.y) + abs(n.z));
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n.xy = n.z >= 0.0 ? n.xy : octahedron_wrap(n.xy);
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n.xy = n.xy * 0.5 + 0.5;
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return n.xy;
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}
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float get_omni_attenuation(float distance, float inv_range, float decay) {
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float nd = distance * inv_range;
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nd *= nd;
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nd *= nd; // nd^4
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nd = max(1.0 - nd, 0.0);
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nd *= nd; // nd^2
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return nd * pow(max(distance, 0.0001), -decay);
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}
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void main() {
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uint voxel_index = uint(gl_GlobalInvocationID.x);
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//used for skipping voxels every N frames
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voxel_index = params.process_offset + voxel_index * params.process_increment;
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if (voxel_index >= dispatch_data.total_count) {
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return;
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}
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uint voxel_position = process_voxels.data[voxel_index].position;
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//keep for storing to texture
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ivec3 positioni = ivec3((uvec3(voxel_position, voxel_position, voxel_position) >> uvec3(0, 7, 14)) & uvec3(0x7F));
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vec3 position = vec3(positioni) + vec3(0.5);
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position /= cascades.data[params.cascade].to_cell;
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position += cascades.data[params.cascade].offset;
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uint voxel_albedo = process_voxels.data[voxel_index].albedo;
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vec3 albedo = vec3(uvec3(voxel_albedo >> 10, voxel_albedo >> 5, voxel_albedo) & uvec3(0x1F)) / float(0x1F);
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vec3 light_accum[6] = vec3[](vec3(0.0), vec3(0.0), vec3(0.0), vec3(0.0), vec3(0.0), vec3(0.0));
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uint valid_aniso = (voxel_albedo >> 15) & 0x3F;
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const vec3 aniso_dir[6] = vec3[](
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vec3(1, 0, 0),
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vec3(0, 1, 0),
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vec3(0, 0, 1),
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vec3(-1, 0, 0),
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vec3(0, -1, 0),
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vec3(0, 0, -1));
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// Add indirect light first, in order to save computation resources
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#ifdef MODE_PROCESS_DYNAMIC
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if (params.multibounce) {
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vec3 pos = (vec3(positioni) + vec3(0.5)) * float(params.probe_axis_size - 1) / params.grid_size;
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ivec3 probe_base_pos = ivec3(pos);
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float weight_accum[6] = float[](0, 0, 0, 0, 0, 0);
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ivec3 tex_pos = ivec3(probe_base_pos.xy, int(params.cascade));
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tex_pos.x += probe_base_pos.z * int(params.probe_axis_size);
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tex_pos.xy = tex_pos.xy * (OCT_SIZE + 2) + ivec2(1);
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vec3 base_tex_posf = vec3(tex_pos);
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vec2 tex_pixel_size = 1.0 / vec2(ivec2((OCT_SIZE + 2) * params.probe_axis_size * params.probe_axis_size, (OCT_SIZE + 2) * params.probe_axis_size));
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vec3 probe_uv_offset = (ivec3(OCT_SIZE + 2, OCT_SIZE + 2, (OCT_SIZE + 2) * params.probe_axis_size)) * tex_pixel_size.xyx;
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for (uint j = 0; j < 8; j++) {
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ivec3 offset = (ivec3(j) >> ivec3(0, 1, 2)) & ivec3(1, 1, 1);
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ivec3 probe_posi = probe_base_pos;
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probe_posi += offset;
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// Compute weight
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vec3 probe_pos = vec3(probe_posi);
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vec3 probe_to_pos = pos - probe_pos;
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vec3 probe_dir = normalize(-probe_to_pos);
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// Compute lightprobe texture position
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vec3 trilinear = vec3(1.0) - abs(probe_to_pos);
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for (uint k = 0; k < 6; k++) {
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if (bool(valid_aniso & (1 << k))) {
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vec3 n = aniso_dir[k];
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float weight = trilinear.x * trilinear.y * trilinear.z * max(0.005, dot(n, probe_dir));
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vec3 tex_posf = base_tex_posf + vec3(octahedron_encode(n) * float(OCT_SIZE), 0.0);
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tex_posf.xy *= tex_pixel_size;
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vec3 pos_uvw = tex_posf;
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pos_uvw.xy += vec2(offset.xy) * probe_uv_offset.xy;
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pos_uvw.x += float(offset.z) * probe_uv_offset.z;
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vec3 indirect_light = textureLod(sampler2DArray(lightprobe_texture, linear_sampler), pos_uvw, 0.0).rgb;
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light_accum[k] += indirect_light * weight;
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weight_accum[k] += weight;
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}
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}
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}
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for (uint k = 0; k < 6; k++) {
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if (weight_accum[k] > 0.0) {
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light_accum[k] /= weight_accum[k];
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light_accum[k] *= albedo;
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}
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}
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}
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#endif
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{
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uint rgbe = process_voxels.data[voxel_index].light;
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//read rgbe8985
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float r = float((rgbe & 0xff) << 1);
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float g = float((rgbe >> 8) & 0x1ff);
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float b = float(((rgbe >> 17) & 0xff) << 1);
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float e = float((rgbe >> 25) & 0x1F);
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float m = pow(2.0, e - 15.0 - 9.0);
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vec3 l = vec3(r, g, b) * m;
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uint aniso = process_voxels.data[voxel_index].light_aniso;
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for (uint i = 0; i < 6; i++) {
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float strength = ((aniso >> (i * 5)) & 0x1F) / float(0x1F);
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light_accum[i] += l * strength;
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}
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}
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// Raytrace light
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vec3 pos_to_uvw = 1.0 / params.grid_size;
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vec3 uvw_ofs = pos_to_uvw * 0.5;
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for (uint i = 0; i < params.light_count; i++) {
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float attenuation = 1.0;
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vec3 direction;
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float light_distance = 1e20;
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switch (lights.data[i].type) {
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case LIGHT_TYPE_DIRECTIONAL: {
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direction = -lights.data[i].direction;
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} break;
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case LIGHT_TYPE_OMNI: {
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vec3 rel_vec = lights.data[i].position - position;
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direction = normalize(rel_vec);
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light_distance = length(rel_vec);
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rel_vec.y /= params.y_mult;
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attenuation = get_omni_attenuation(light_distance, 1.0 / lights.data[i].radius, lights.data[i].attenuation);
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} break;
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case LIGHT_TYPE_SPOT: {
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vec3 rel_vec = lights.data[i].position - position;
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direction = normalize(rel_vec);
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light_distance = length(rel_vec);
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rel_vec.y /= params.y_mult;
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attenuation = get_omni_attenuation(light_distance, 1.0 / lights.data[i].radius, lights.data[i].attenuation);
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float angle = acos(dot(normalize(rel_vec), -lights.data[i].direction));
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if (angle > lights.data[i].spot_angle) {
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attenuation = 0.0;
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} else {
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float d = clamp(angle / lights.data[i].spot_angle, 0, 1);
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attenuation *= pow(1.0 - d, lights.data[i].spot_attenuation);
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}
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} break;
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}
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if (attenuation < 0.001) {
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continue;
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}
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bool hit = false;
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vec3 ray_pos = position;
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vec3 ray_dir = direction;
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vec3 inv_dir = 1.0 / ray_dir;
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//this is how to properly bias outgoing rays
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float cell_size = 1.0 / cascades.data[params.cascade].to_cell;
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ray_pos += sign(direction) * cell_size * 0.48; // go almost to the box edge but remain inside
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ray_pos += ray_dir * 0.4 * cell_size; //apply a small bias from there
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for (uint j = params.cascade; j < params.max_cascades; j++) {
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//convert to local bounds
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vec3 pos = ray_pos - cascades.data[j].offset;
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pos *= cascades.data[j].to_cell;
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float local_distance = light_distance * cascades.data[j].to_cell;
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if (any(lessThan(pos, vec3(0.0))) || any(greaterThanEqual(pos, params.grid_size))) {
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continue; //already past bounds for this cascade, goto next
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}
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//find maximum advance distance (until reaching bounds)
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vec3 t0 = -pos * inv_dir;
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vec3 t1 = (params.grid_size - pos) * inv_dir;
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vec3 tmax = max(t0, t1);
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float max_advance = min(tmax.x, min(tmax.y, tmax.z));
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max_advance = min(local_distance, max_advance);
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float advance = 0.0;
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float occlusion = 1.0;
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while (advance < max_advance) {
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//read how much to advance from SDF
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vec3 uvw = (pos + ray_dir * advance) * pos_to_uvw;
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float distance = texture(sampler3D(sdf_cascades[j], linear_sampler), uvw).r * 255.0 - 1.0;
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if (distance < 0.001) {
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//consider hit
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hit = true;
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break;
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}
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occlusion = min(occlusion, distance);
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advance += distance;
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}
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if (hit) {
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attenuation *= occlusion;
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break;
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}
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if (advance >= local_distance) {
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break; //past light distance, abandon search
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}
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//change ray origin to collision with bounds
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pos += ray_dir * max_advance;
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pos /= cascades.data[j].to_cell;
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pos += cascades.data[j].offset;
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light_distance -= max_advance / cascades.data[j].to_cell;
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ray_pos = pos;
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}
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if (!hit) {
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vec3 light = albedo * lights.data[i].color.rgb * lights.data[i].energy * attenuation;
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for (int j = 0; j < 6; j++) {
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if (bool(valid_aniso & (1 << j))) {
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light_accum[j] += max(0.0, dot(aniso_dir[j], direction)) * light;
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}
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}
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}
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}
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// Store the light in the light texture
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float lumas[6];
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vec3 light_total = vec3(0);
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for (int i = 0; i < 6; i++) {
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light_total += light_accum[i];
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lumas[i] = max(light_accum[i].r, max(light_accum[i].g, light_accum[i].b));
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}
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float luma_total = max(light_total.r, max(light_total.g, light_total.b));
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uint light_total_rgbe;
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{
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//compress to RGBE9995 to save space
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const float pow2to9 = 512.0f;
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const float B = 15.0f;
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const float N = 9.0f;
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const float LN2 = 0.6931471805599453094172321215;
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float cRed = clamp(light_total.r, 0.0, 65408.0);
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float cGreen = clamp(light_total.g, 0.0, 65408.0);
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float cBlue = clamp(light_total.b, 0.0, 65408.0);
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float cMax = max(cRed, max(cGreen, cBlue));
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float expp = max(-B - 1.0f, floor(log(cMax) / LN2)) + 1.0f + B;
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float sMax = floor((cMax / pow(2.0f, expp - B - N)) + 0.5f);
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float exps = expp + 1.0f;
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if (0.0 <= sMax && sMax < pow2to9) {
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exps = expp;
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}
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float sRed = floor((cRed / pow(2.0f, exps - B - N)) + 0.5f);
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float sGreen = floor((cGreen / pow(2.0f, exps - B - N)) + 0.5f);
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float sBlue = floor((cBlue / pow(2.0f, exps - B - N)) + 0.5f);
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#ifdef MODE_PROCESS_STATIC
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//since its self-save, use RGBE8985
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light_total_rgbe = ((uint(sRed) & 0x1FF) >> 1) | ((uint(sGreen) & 0x1FF) << 8) | (((uint(sBlue) & 0x1FF) >> 1) << 17) | ((uint(exps) & 0x1F) << 25);
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#else
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light_total_rgbe = (uint(sRed) & 0x1FF) | ((uint(sGreen) & 0x1FF) << 9) | ((uint(sBlue) & 0x1FF) << 18) | ((uint(exps) & 0x1F) << 27);
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#endif
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}
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#ifdef MODE_PROCESS_DYNAMIC
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vec4 aniso0;
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aniso0.r = lumas[0] / luma_total;
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aniso0.g = lumas[1] / luma_total;
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aniso0.b = lumas[2] / luma_total;
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aniso0.a = lumas[3] / luma_total;
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vec2 aniso1;
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aniso1.r = lumas[4] / luma_total;
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aniso1.g = lumas[5] / luma_total;
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//save to 3D textures
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imageStore(dst_aniso0, positioni, aniso0);
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imageStore(dst_aniso1, positioni, vec4(aniso1, 0.0, 0.0));
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imageStore(dst_light, positioni, uvec4(light_total_rgbe));
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//also fill neighbours, so light interpolation during the indirect pass works
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//recover the neighbour list from the leftover bits
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uint neighbours = (voxel_albedo >> 21) | ((voxel_position >> 21) << 11) | ((process_voxels.data[voxel_index].light >> 30) << 22) | ((process_voxels.data[voxel_index].light_aniso >> 30) << 24);
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const uint max_neighbours = 26;
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const ivec3 neighbour_positions[max_neighbours] = ivec3[](
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ivec3(-1, -1, -1),
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ivec3(-1, -1, 0),
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ivec3(-1, -1, 1),
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ivec3(-1, 0, -1),
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ivec3(-1, 0, 0),
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ivec3(-1, 0, 1),
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ivec3(-1, 1, -1),
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ivec3(-1, 1, 0),
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ivec3(-1, 1, 1),
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ivec3(0, -1, -1),
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ivec3(0, -1, 0),
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ivec3(0, -1, 1),
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ivec3(0, 0, -1),
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ivec3(0, 0, 1),
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ivec3(0, 1, -1),
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ivec3(0, 1, 0),
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ivec3(0, 1, 1),
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ivec3(1, -1, -1),
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ivec3(1, -1, 0),
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ivec3(1, -1, 1),
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ivec3(1, 0, -1),
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ivec3(1, 0, 0),
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ivec3(1, 0, 1),
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ivec3(1, 1, -1),
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ivec3(1, 1, 0),
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ivec3(1, 1, 1));
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for (uint i = 0; i < max_neighbours; i++) {
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if (bool(neighbours & (1 << i))) {
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ivec3 neighbour_pos = positioni + neighbour_positions[i];
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imageStore(dst_light, neighbour_pos, uvec4(light_total_rgbe));
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imageStore(dst_aniso0, neighbour_pos, aniso0);
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imageStore(dst_aniso1, neighbour_pos, vec4(aniso1, 0.0, 0.0));
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}
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}
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#endif
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#ifdef MODE_PROCESS_STATIC
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|
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//save back the anisotropic
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|
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uint light = process_voxels.data[voxel_index].light & (3 << 30);
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|
light |= light_total_rgbe;
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process_voxels.data[voxel_index].light = light; //replace
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|
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uint light_aniso = process_voxels.data[voxel_index].light_aniso & (3 << 30);
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for (int i = 0; i < 6; i++) {
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light_aniso |= min(31, uint((lumas[i] / luma_total) * 31.0)) << (i * 5);
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}
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|
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process_voxels.data[voxel_index].light_aniso = light_aniso;
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|
|
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#endif
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}
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