a616ffa8ac
# Objective Add web support to atmosphere by gating dual source blending and using a macro to determine the target platform. The main objective of this PR is to ensure that users of Bevy's atmosphere feature can also run it in a web-based context where WebGPU support is enabled. ## Solution - Make use of the `#[cfg(not(target_arch = "wasm32"))]` macro to gate the dual source blending, as this is not (yet) supported in web browsers. - Rename the function `sample_sun_illuminance` to `sample_sun_radiance` and move calls out of conditionals to ensure the shader compiles and runs in both native and web-based contexts. - Moved the multiplication of the transmittance out when calculating the sun color, because calling the `sample_sun_illuminance` function was causing issues in web. Overall this results in cleaner code and more readable. ## Testing - Tested by building a wasm target and loading it in a web page with Vite dev server using `mate-h/bevy-webgpu` repo template. - Tested the native build with `cargo run --example atmosphere` to ensure it still works with dual source blending. --- ## Showcase Screenshots show the atmosphere example running in two different contexts: <img width="1281" alt="atmosphere-web-showcase" src="https://github.com/user-attachments/assets/40b1ee91-89ae-41a6-8189-89630d1ca1a6" /> --------- Co-authored-by: JMS55 <47158642+JMS55@users.noreply.github.com>
59 lines
2.0 KiB
WebGPU Shading Language
59 lines
2.0 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_transmittance_lut_segment,
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sample_sky_view_lut, direction_world_to_atmosphere,
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uv_to_ray_direction, uv_to_ndc, sample_aerial_view_lut,
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view_radius, sample_sun_radiance, ndc_to_camera_dist
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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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struct RenderSkyOutput {
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@location(0) inscattering: vec4<f32>,
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#ifdef DUAL_SOURCE_BLENDING
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@location(0) @second_blend_source transmittance: vec4<f32>,
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#endif
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}
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@fragment
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fn main(in: FullscreenVertexOutput) -> RenderSkyOutput {
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let depth = textureLoad(depth_texture, vec2<i32>(in.position.xy), 0);
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let ray_dir_ws = uv_to_ray_direction(in.uv);
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let r = view_radius();
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let mu = ray_dir_ws.y;
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var transmittance: vec3<f32>;
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var inscattering: vec3<f32>;
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let sun_radiance = sample_sun_radiance(ray_dir_ws.xyz);
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if depth == 0.0 {
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let ray_dir_as = direction_world_to_atmosphere(ray_dir_ws.xyz);
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transmittance = sample_transmittance_lut(r, mu);
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inscattering += sample_sky_view_lut(r, ray_dir_as);
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inscattering += sun_radiance * transmittance * view.exposure;
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} else {
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let t = ndc_to_camera_dist(vec3(uv_to_ndc(in.uv), depth));
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inscattering = sample_aerial_view_lut(in.uv, t);
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transmittance = sample_transmittance_lut_segment(r, mu, t);
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}
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#ifdef DUAL_SOURCE_BLENDING
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return RenderSkyOutput(vec4(inscattering, 0.0), vec4(transmittance, 1.0));
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#else
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let mean_transmittance = (transmittance.r + transmittance.g + transmittance.b) / 3.0;
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return RenderSkyOutput(vec4(inscattering, mean_transmittance));
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#endif
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}
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