bevy/crates/bevy_pbr/src/prepass/prepass.wgsl

#import bevy_pbr::prepass_bindings
#import bevy_pbr::mesh_functions

// Most of these attributes are not used in the default prepass fragment shader, but they are still needed so we can
// pass them to custom prepass shaders like pbr_prepass.wgsl.
struct Vertex {
    @location(0) position: vec3<f32>,

#ifdef VERTEX_UVS
    @location(1) uv: vec2<f32>,
#endif // VERTEX_UVS

#ifdef NORMAL_PREPASS
    @location(2) normal: vec3<f32>,
#ifdef VERTEX_TANGENTS
    @location(3) tangent: vec4<f32>,
#endif // VERTEX_TANGENTS
#endif // NORMAL_PREPASS

#ifdef SKINNED
    @location(4) joint_indices: vec4<u32>,
    @location(5) joint_weights: vec4<f32>,
#endif // SKINNED
}

struct VertexOutput {
    @builtin(position) clip_position: vec4<f32>,

#ifdef VERTEX_UVS
    @location(0) uv: vec2<f32>,
#endif // VERTEX_UVS

#ifdef NORMAL_PREPASS
    @location(1) world_normal: vec3<f32>,
#ifdef VERTEX_TANGENTS
    @location(2) world_tangent: vec4<f32>,
#endif // VERTEX_TANGENTS
#endif // NORMAL_PREPASS
}

@vertex
fn vertex(vertex: Vertex) -> VertexOutput {
    var out: VertexOutput;

#ifdef SKINNED
    var model = skin_model(vertex.joint_indices, vertex.joint_weights);
#else // SKINNED
    var model = mesh.model;
#endif // SKINNED

    out.clip_position = mesh_position_local_to_clip(model, vec4(vertex.position, 1.0));
#ifdef DEPTH_CLAMP_ORTHO
        out.clip_position.z = min(out.clip_position.z, 1.0);
#endif // DEPTH_CLAMP_ORTHO

#ifdef VERTEX_UVS
    out.uv = vertex.uv;
#endif // VERTEX_UVS

#ifdef NORMAL_PREPASS
#ifdef SKINNED
    out.world_normal = skin_normals(model, vertex.normal);
#else // SKINNED
    out.world_normal = mesh_normal_local_to_world(vertex.normal);
#endif // SKINNED

#ifdef VERTEX_TANGENTS
    out.world_tangent = mesh_tangent_local_to_world(model, vertex.tangent);
#endif // VERTEX_TANGENTS
#endif // NORMAL_PREPASS

    return out;
}

#ifdef NORMAL_PREPASS
struct FragmentInput {
    @location(1) world_normal: vec3<f32>,
}

@fragment
fn fragment(in: FragmentInput) -> @location(0) vec4<f32> {
    return vec4(in.world_normal * 0.5 + vec3(0.5), 1.0);
}
#endif // NORMAL_PREPASS