bevy/assets/shaders/array_texture.wgsl
Robert Swain 84991d34f3 Array texture example (#5077)
# Objective

- Make the reusable PBR shading functionality a little more reusable
  - Add constructor functions for `StandardMaterial` and `PbrInput` structs to populate them with default values
  - Document unclear `PbrInput` members
- Demonstrate how to reuse the bevy PBR shading functionality
- The final important piece from #3969 as the initial shot at making the PBR shader code reusable in custom materials

## Solution

- Add back and rework the 'old' `array_texture` example from pre-0.6.
- Create a custom shader material
  - Use a single array texture binding and sampler for the material bind group
  - Use a shader that calls `pbr()` from the `bevy_pbr::pbr_functions` import
- Spawn a row of cubes using the custom material
- In the shader, select the array texture layer to sample by using the world position x coordinate modulo the number of array texture layers

<img width="1392" alt="Screenshot 2022-06-23 at 12 28 05" src="https://user-images.githubusercontent.com/302146/175278593-2296f519-f577-4ece-81c0-d842283784a1.png">

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-06-28 00:58:50 +00:00

64 lines
1.8 KiB
WebGPU Shading Language

#import bevy_pbr::mesh_view_bindings
#import bevy_pbr::mesh_bindings
#import bevy_pbr::pbr_types
#import bevy_pbr::utils
#import bevy_pbr::clustered_forward
#import bevy_pbr::lighting
#import bevy_pbr::shadows
#import bevy_pbr::pbr_functions
[[group(1), binding(0)]]
var my_array_texture: texture_2d_array<f32>;
[[group(1), binding(1)]]
var my_array_texture_sampler: sampler;
struct FragmentInput {
[[builtin(front_facing)]] is_front: bool;
[[builtin(position)]] frag_coord: vec4<f32>;
[[location(0)]] world_position: vec4<f32>;
[[location(1)]] world_normal: vec3<f32>;
[[location(2)]] uv: vec2<f32>;
#ifdef VERTEX_TANGENTS
[[location(3)]] world_tangent: vec4<f32>;
#endif
#ifdef VERTEX_COLORS
[[location(4)]] color: vec4<f32>;
#endif
};
[[stage(fragment)]]
fn fragment(in: FragmentInput) -> [[location(0)]] vec4<f32> {
let layer = i32(in.world_position.x) & 0x3;
// Prepare a 'processed' StandardMaterial by sampling all textures to resolve
// the material members
var pbr_input: PbrInput = pbr_input_new();
pbr_input.material.base_color = textureSample(my_array_texture, my_array_texture_sampler, in.uv, layer);
#ifdef VERTEX_COLORS
pbr_input.material.base_color = pbr_input.material.base_color * in.color;
#endif
pbr_input.frag_coord = in.frag_coord;
pbr_input.world_position = in.world_position;
pbr_input.world_normal = in.world_normal;
pbr_input.is_orthographic = view.projection[3].w == 1.0;
pbr_input.N = prepare_normal(
pbr_input.material.flags,
in.world_normal,
#ifdef VERTEX_TANGENTS
#ifdef STANDARDMATERIAL_NORMAL_MAP
in.world_tangent,
#endif
#endif
in.uv,
in.is_front,
);
pbr_input.V = calculate_view(in.world_position, pbr_input.is_orthographic);
return pbr(pbr_input);
}