forestia/bevy
2
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Factor BRDF in spatial resampling (improves quality)

Browse Source
This commit is contained in:
JMS55 2025-07-10 21:50:28 -04:00
parent cf3ff07cf9
commit 7b8abcfb59
2 changed files with 32 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
crates/bevy_solari/src/realtime/restir_di.wgsl
View File

@ -49,9 +49,9 @@ fn initial_and_temporal(@builtin(global_invocation_id) global_id: vec3<u32>) {
let initial_reservoir = generate_initial_reservoir(world_position, world_normal, diffuse_brdf, &rng);
let temporal_reservoir = load_temporal_reservoir(global_id.xy, depth, world_position, world_normal);
let combined_reservoir = merge_reservoirs(initial_reservoir, temporal_reservoir, world_position, world_normal, diffuse_brdf, &rng);
let merge_result = merge_reservoirs(initial_reservoir, temporal_reservoir, world_position, world_normal, diffuse_brdf, &rng);
di_reservoirs_b[pixel_index] = combined_reservoir.merged_reservoir;
di_reservoirs_b[pixel_index] = merge_result.merged_reservoir;
}
@compute @workgroup_size(8, 8, 1)

43
crates/bevy_solari/src/realtime/restir_gi.wgsl
View File

@ -44,9 +44,9 @@ fn initial_and_temporal(@builtin(global_invocation_id) global_id: vec3<u32>) {
let initial_reservoir = generate_initial_reservoir(world_position, world_normal, &rng);
let temporal_reservoir = load_temporal_reservoir(global_id.xy, depth, world_position, world_normal);
let combined_reservoir = merge_reservoirs(initial_reservoir, temporal_reservoir, &rng);
let merge_result = merge_reservoirs(initial_reservoir, temporal_reservoir, vec3(1.0), vec3(1.0), &rng);
gi_reservoirs_b[pixel_index] = combined_reservoir;
gi_reservoirs_b[pixel_index] = merge_result.merged_reservoir;
}
@compute @workgroup_size(8, 8, 1)
@ -69,15 +69,17 @@ fn spatial_and_shade(@builtin(global_invocation_id) global_id: vec3<u32>) {
let input_reservoir = gi_reservoirs_b[pixel_index];
let spatial_reservoir = load_spatial_reservoir(global_id.xy, depth, world_position, world_normal, &rng);
let combined_reservoir = merge_reservoirs(input_reservoir, spatial_reservoir, &rng);
let input_factor = dot(normalize(input_reservoir.sample_point_world_position - world_position), world_normal) * diffuse_brdf;
let spatial_factor = dot(normalize(spatial_reservoir.sample_point_world_position - world_position), world_normal) * diffuse_brdf;
let merge_result = merge_reservoirs(input_reservoir, spatial_reservoir, input_factor, spatial_factor, &rng);
let combined_reservoir = merge_result.merged_reservoir;
gi_reservoirs_a[pixel_index] = combined_reservoir;
let cos_theta = dot(normalize(combined_reservoir.sample_point_world_position - world_position), world_normal);
let radiance = combined_reservoir.radiance * diffuse_brdf * cos_theta;
var pixel_color = textureLoad(view_output, global_id.xy);
pixel_color += vec4(radiance * combined_reservoir.unbiased_contribution_weight * view.exposure, 0.0);
pixel_color += vec4(merge_result.selected_sample_radiance * combined_reservoir.unbiased_contribution_weight * view.exposure, 0.0);
textureStore(view_output, global_id.xy, pixel_color);
}
@ -254,21 +256,34 @@ fn empty_reservoir() -> Reservoir {
);
}
fn merge_reservoirs(canonical_reservoir: Reservoir, other_reservoir: Reservoir, rng: ptr<function, u32>) -> Reservoir {
struct ReservoirMergeResult {
merged_reservoir: Reservoir,
selected_sample_radiance: vec3<f32>,
}
fn merge_reservoirs(
canonical_reservoir: Reservoir,
other_reservoir: Reservoir,
canonical_factor: vec3<f32>,
other_factor: vec3<f32>,
rng: ptr<function, u32>,
) -> ReservoirMergeResult {
var combined_reservoir = empty_reservoir();
combined_reservoir.confidence_weight = canonical_reservoir.confidence_weight + other_reservoir.confidence_weight;
if combined_reservoir.confidence_weight == 0.0 { return combined_reservoir; }
if combined_reservoir.confidence_weight == 0.0 { return ReservoirMergeResult(combined_reservoir, vec3(0.0)); }
// TODO: Balance heuristic MIS weights
let mis_weight_denominator = 1.0 / combined_reservoir.confidence_weight;
let canonical_mis_weight = canonical_reservoir.confidence_weight * mis_weight_denominator;
let canonical_target_function = luminance(canonical_reservoir.radiance);
let canonical_radiance = canonical_reservoir.radiance * canonical_factor;
let canonical_target_function = luminance(canonical_radiance);
let canonical_resampling_weight = canonical_mis_weight * (canonical_target_function * canonical_reservoir.unbiased_contribution_weight);
let other_mis_weight = other_reservoir.confidence_weight * mis_weight_denominator;
let other_target_function = luminance(other_reservoir.radiance);
let other_radiance = other_reservoir.radiance * other_factor;
let other_target_function = luminance(other_radiance);
let other_resampling_weight = other_mis_weight * (other_target_function * other_reservoir.unbiased_contribution_weight);
combined_reservoir.weight_sum = canonical_resampling_weight + other_resampling_weight;
@ -280,6 +295,8 @@ fn merge_reservoirs(canonical_reservoir: Reservoir, other_reservoir: Reservoir,
let inverse_target_function = select(0.0, 1.0 / other_target_function, other_target_function > 0.0);
combined_reservoir.unbiased_contribution_weight = combined_reservoir.weight_sum * inverse_target_function;
return ReservoirMergeResult(combined_reservoir, other_radiance);
} else {
combined_reservoir.sample_point_world_position = canonical_reservoir.sample_point_world_position;
combined_reservoir.sample_point_world_normal = canonical_reservoir.sample_point_world_normal;
@ -287,7 +304,7 @@ fn merge_reservoirs(canonical_reservoir: Reservoir, other_reservoir: Reservoir,
let inverse_target_function = select(0.0, 1.0 / canonical_target_function, canonical_target_function > 0.0);
combined_reservoir.unbiased_contribution_weight = combined_reservoir.weight_sum * inverse_target_function;
}
return combined_reservoir;
return ReservoirMergeResult(combined_reservoir, canonical_radiance);
}
}