81a25bb0c7
Implement procedural atmospheric scattering from [Sebastien Hillaire's 2020 paper](https://sebh.github.io/publications/egsr2020.pdf). This approach should scale well even down to mobile hardware, and is physically accurate. ## Co-author: @mate-h He helped massively with getting this over the finish line, ensuring everything was physically correct, correcting several places where I had misunderstood or misapplied the paper, and improving the performance in several places as well. Thanks! ## Credits @aevyrie: helped find numerous bugs and improve the example to best show off this feature :) Built off of @mtsr's original branch, which handled the transmittance lut (arguably the most important part) ## Showcase:   ## For followup - Integrate with pcwalton's volumetrics code - refactor/reorganize for better integration with other effects - have atmosphere transmittance affect directional lights - add support for generating skybox/environment map --------- Co-authored-by: Emerson Coskey <56370779+EmersonCoskey@users.noreply.github.com> Co-authored-by: atlv <email@atlasdostal.com> Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com> Co-authored-by: Emerson Coskey <coskey@emerlabs.net> Co-authored-by: Máté Homolya <mate.homolya@gmail.com>
40 lines
1.4 KiB
WebGPU Shading Language
40 lines
1.4 KiB
WebGPU Shading Language
#import bevy_pbr::atmosphere::{
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types::{Atmosphere, AtmosphereSettings},
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bindings::{atmosphere, view, atmosphere_transforms},
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functions::{
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sample_transmittance_lut, sample_sky_view_lut,
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direction_world_to_atmosphere, uv_to_ray_direction,
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uv_to_ndc, sample_aerial_view_lut, view_radius,
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sample_sun_illuminance,
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},
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};
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#import bevy_render::view::View;
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#import bevy_core_pipeline::fullscreen_vertex_shader::FullscreenVertexOutput
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#ifdef MULTISAMPLED
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@group(0) @binding(13) var depth_texture: texture_depth_multisampled_2d;
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#else
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@group(0) @binding(13) var depth_texture: texture_depth_2d;
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#endif
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@fragment
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fn main(in: FullscreenVertexOutput) -> @location(0) vec4<f32> {
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let depth = textureLoad(depth_texture, vec2<i32>(in.position.xy), 0);
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if depth == 0.0 {
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let ray_dir_ws = uv_to_ray_direction(in.uv);
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let ray_dir_as = direction_world_to_atmosphere(ray_dir_ws.xyz);
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let r = view_radius();
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let mu = ray_dir_ws.y;
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let transmittance = sample_transmittance_lut(r, mu);
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let inscattering = sample_sky_view_lut(r, ray_dir_as);
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let sun_illuminance = sample_sun_illuminance(ray_dir_ws.xyz, transmittance);
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return vec4(inscattering + sun_illuminance, (transmittance.r + transmittance.g + transmittance.b) / 3.0);
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} else {
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return sample_aerial_view_lut(in.uv, depth);
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}
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}
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