forestiles/assets/render/pbr.wgsl
2025-07-20 12:00:43 +02:00

108 lines
3.4 KiB
WebGPU Shading Language

#import bevy_pbr::{
pbr_types,
pbr_functions::alpha_discard,
pbr_fragment::pbr_input_from_standard_material,
decal::clustered::apply_decal_base_color,
}
#ifdef PREPASS_PIPELINE
#import bevy_pbr::{
prepass_io::{VertexOutput, FragmentOutput},
pbr_deferred_functions::deferred_output,
}
#else
#import bevy_pbr::{
forward_io::{VertexOutput, FragmentOutput},
pbr_functions,
pbr_functions::{apply_pbr_lighting, main_pass_post_lighting_processing},
pbr_types::STANDARD_MATERIAL_FLAGS_UNLIT_BIT,
}
#endif
#ifdef MESHLET_MESH_MATERIAL_PASS
#import bevy_pbr::meshlet_visibility_buffer_resolve::resolve_vertex_output
#endif
#ifdef OIT_ENABLED
#import bevy_core_pipeline::oit::oit_draw
#endif // OIT_ENABLED
#ifdef FORWARD_DECAL
#import bevy_pbr::decal::forward::get_forward_decal_info
#endif
@fragment
fn fragment(
#ifdef MESHLET_MESH_MATERIAL_PASS
@builtin(position) frag_coord: vec4<f32>,
#else
vertex_output: VertexOutput,
@builtin(front_facing) is_front: bool,
#endif
) -> FragmentOutput {
#ifdef MESHLET_MESH_MATERIAL_PASS
let vertex_output = resolve_vertex_output(frag_coord);
let is_front = true;
#endif
var in = vertex_output;
// If we're in the crossfade section of a visibility range, conditionally
// discard the fragment according to the visibility pattern.
#ifdef VISIBILITY_RANGE_DITHER
pbr_functions::visibility_range_dither(in.position, in.visibility_range_dither);
#endif
#ifdef FORWARD_DECAL
let forward_decal_info = get_forward_decal_info(in);
in.world_position = forward_decal_info.world_position;
in.uv = forward_decal_info.uv;
#endif
// generate a PbrInput struct from the StandardMaterial bindings
var pbr_input = pbr_input_from_standard_material(in, is_front);
// alpha discard
pbr_input.material.base_color = alpha_discard(pbr_input.material, pbr_input.material.base_color);
// clustered decals
pbr_input.material.base_color = apply_decal_base_color(
in.world_position.xyz,
in.position.xy,
pbr_input.material.base_color
);
#ifdef PREPASS_PIPELINE
// write the gbuffer, lighting pass id, and optionally normal and motion_vector textures
let out = deferred_output(in, pbr_input);
#else
// in forward mode, we calculate the lit color immediately, and then apply some post-lighting effects here.
// in deferred mode the lit color and these effects will be calculated in the deferred lighting shader
var out: FragmentOutput;
if (pbr_input.material.flags & STANDARD_MATERIAL_FLAGS_UNLIT_BIT) == 0u {
out.color = apply_pbr_lighting(pbr_input);
} else {
out.color = pbr_input.material.base_color;
}
// apply in-shader post processing (fog, alpha-premultiply, and also tonemapping, debanding if the camera is non-hdr)
// note this does not include fullscreen postprocessing effects like bloom.
out.color = main_pass_post_lighting_processing(pbr_input, out.color);
#endif
#ifdef OIT_ENABLED
let alpha_mode = pbr_input.material.flags & pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_RESERVED_BITS;
if alpha_mode != pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_OPAQUE {
// The fragments will only be drawn during the oit resolve pass.
oit_draw(in.position, out.color);
discard;
}
#endif // OIT_ENABLED
#ifdef FORWARD_DECAL
out.color.a = min(forward_decal_info.alpha, out.color.a);
#endif
return out;
}