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

Use interleaved_gradient_noise() instead of screen_space_dither()

Browse Source
This commit is contained in:
Marco Buono 2023-04-25 00:49:04 -03:00
parent 94e3099bd8
commit a0535deb49
1 changed files with 48 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
crates/bevy_pbr/src/render/pbr_lighting.wgsl
View File

@ -313,6 +313,25 @@ fn transmissive_light(world_position: vec4<f32>, frag_coord: vec3<f32>, N: vec3<
return transmissive_color * mix(transmitted_environment_light_specular, background_color.rgb, background_color.a);
}
// https://blog.demofox.org/2022/01/01/interleaved-gradient-noise-a-different-kind-of-low-discrepancy-sequence
fn interleaved_gradient_noise(pixel_coordinates: vec2<f32>) -> f32 {
let frame = f32(globals.frame_count % 64u);
let xy = pixel_coordinates + 5.588238 * frame;
return fract(52.9829189 * fract(0.06711056 * xy.x + 0.00583715 * xy.y));
}
// https://www.iryoku.com/next-generation-post-processing-in-call-of-duty-advanced-warfare (slides 120-135)
const sample_offsets: array<vec2<f32>, 8> = array<vec2<f32>, 8>(
vec2<f32>(-0.7071, 0.7071),
vec2<f32>(-0.0000, -0.8750),
vec2<f32>( 0.5303, 0.5303),
vec2<f32>(-0.6250, -0.0000),
vec2<f32>( 0.3536, -0.3536),
vec2<f32>(-0.0000, 0.3750),
vec2<f32>(-0.1768, -0.1768),
vec2<f32>( 0.1250, 0.0000),
);
fn fetch_transmissive_background(offset_position: vec2<f32>, frag_coord: vec3<f32>, perceptual_roughness: f32, distance: f32) -> vec4<f32> {
// Calculate view aspect ratio, used to scale offset so that it's proportionate
let aspect = view.viewport.z / view.viewport.w;
@ -329,25 +348,45 @@ fn fetch_transmissive_background(offset_position: vec2<f32>, frag_coord: vec3<f3
let blur_intensity = perceptual_roughness / distance;
// Number of taps scale with blur intensity
// Minimum: 1, Maximum: 9
let num_taps = i32(min(blur_intensity * 300.0, 8.0)) + 1;
// Minimum: 1, Maximum: 8
let num_taps = i32(min(blur_intensity * 90.0, 7.0)) + 1;
var result = vec4<f32>(0.0);
for (var i: i32 = 0; i < num_taps; i = i + 1) {
// Magic numbers have been empirically chosen to produce blurry results that look “smooth”
let dither = screen_space_dither(frag_coord.xy + vec2<f32>(f32(i) * 4773.0, f32(i) * 1472.0));
let dither_offset = (blur_intensity * 7.0) * (blur_intensity * 7.0) * (30.0 * dither.yz + 0.03 * normalize(dither).xy) * vec2<f32>(1.0, -aspect);
let offset_position_with_dither = offset_position + dither_offset;
let random_angle = 2.0 * PI * interleaved_gradient_noise(frag_coord.xy);
let m = vec2(sin(random_angle), cos(random_angle));
let rotation_matrix = mat2x2(
m.y, -m.x,
m.x, m.y
);
var sample_offset: vec2<f32>;
switch i {
// TODO: Figure out a more reasonable way of doing this, as WGSL
// seems to only allow constant indexes into the constant array
case 0: { sample_offset = sample_offsets[0]; }
case 1: { sample_offset = sample_offsets[1]; }
case 2: { sample_offset = sample_offsets[2]; }
case 3: { sample_offset = sample_offsets[3]; }
case 4: { sample_offset = sample_offsets[4]; }
case 5: { sample_offset = sample_offsets[5]; }
case 6: { sample_offset = sample_offsets[6]; }
case 7: { sample_offset = sample_offsets[7]; }
default: {}
}
let modified_offset_position = offset_position + (rotation_matrix * sample_offset) * blur_intensity * blur_intensity * 5.0;
// Use depth prepass data to reject values that are in front of the current fragment
if (prepass_depth(vec4<f32>(offset_position_with_dither * view.viewport.zw, 0.0, 0.0), 0u) > frag_coord.z) {
if (prepass_depth(vec4<f32>(modified_offset_position * view.viewport.zw, 0.0, 0.0), 0u) > frag_coord.z) {
continue;
}
// Sample the view transmission texture at the offset position + dither offset, to get the background color
// Sample the view transmission texture at the offset position + noise offset, to get the background color
result += textureSample(
view_transmission_texture,
view_transmission_sampler,
offset_position_with_dither,
modified_offset_position,
);
}