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mgi388
d60a1b8166
## Objective - When looking at the `array_texture` example, it wasn't clear to me how I could send the "layer" to the GPU, but it turns out that [MeshTag is one recommended way](https://discord.com/channels/691052431525675048/866787577687310356/1444495450999754823) to pass this. - The example previously extracted a fake "layer" from the world position, but IIUC this isn't the most realistic way to demonstrate layer selection. ## Solution - Update the `array_texture` example by using `MeshTag`. - Add a system to the example that periodically changes the `MeshTag` on entities to show that the mesh tag can also change dynamically at runtime (and show how easy it is). ## Testing and showcase Before, you can see each cube's texture is fixed. <img width="1280" height="747" alt="image" src="https://github.com/user-attachments/assets/1ffde7db-8110-4431-b4e8-3a5a4ba5c5db" /> After, you can see each cube's texture changes as time passes. https://github.com/user-attachments/assets/b1227659-5886-4d2c-a401-84b80423c798 ---- I'm hoping for a rendering dev to validate this approach is correct, and useful. I think it is, but [I'm only just starting to understand](https://discord.com/channels/691052431525675048/866787577687310356/1444888786478829668) how to use this stuff and it's [possibly not the only way](https://discord.com/channels/691052431525675048/866787577687310356/1444888304020488365) so I don't want to submit this if it's the wrong approach to teach future me's.
62 lines
2.1 KiB
WebGPU Shading Language
62 lines
2.1 KiB
WebGPU Shading Language
#import bevy_pbr::{
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forward_io::VertexOutput,
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mesh_functions,
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mesh_view_bindings::view,
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pbr_types::{STANDARD_MATERIAL_FLAGS_DOUBLE_SIDED_BIT, PbrInput, pbr_input_new},
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pbr_functions as fns,
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pbr_bindings,
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}
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#import bevy_core_pipeline::tonemapping::tone_mapping
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@group(#{MATERIAL_BIND_GROUP}) @binding(0) var my_array_texture: texture_2d_array<f32>;
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@group(#{MATERIAL_BIND_GROUP}) @binding(1) var my_array_texture_sampler: sampler;
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@fragment
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fn fragment(
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@builtin(front_facing) is_front: bool,
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mesh: VertexOutput,
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) -> @location(0) vec4<f32> {
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// Determine which layer of the array texture to sample from based on the
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// mesh tag which originates from the MeshTag component on the entity.
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let layer = mesh_functions::get_tag(mesh.instance_index);
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// Prepare a 'processed' StandardMaterial by sampling all textures to resolve
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// the material members
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var pbr_input: PbrInput = pbr_input_new();
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pbr_input.material.base_color = textureSample(my_array_texture, my_array_texture_sampler, mesh.uv, layer);
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#ifdef VERTEX_COLORS
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pbr_input.material.base_color = pbr_input.material.base_color * mesh.color;
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#endif
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let double_sided = (pbr_input.material.flags & STANDARD_MATERIAL_FLAGS_DOUBLE_SIDED_BIT) != 0u;
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pbr_input.frag_coord = mesh.position;
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pbr_input.world_position = mesh.world_position;
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pbr_input.world_normal = fns::prepare_world_normal(
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mesh.world_normal,
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double_sided,
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is_front,
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);
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pbr_input.is_orthographic = view.clip_from_view[3].w == 1.0;
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pbr_input.N = normalize(pbr_input.world_normal);
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#ifdef VERTEX_TANGENTS
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let Nt = textureSampleBias(pbr_bindings::normal_map_texture, pbr_bindings::normal_map_sampler, mesh.uv, view.mip_bias).rgb;
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let TBN = fns::calculate_tbn_mikktspace(mesh.world_normal, mesh.world_tangent);
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pbr_input.N = fns::apply_normal_mapping(
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pbr_input.material.flags,
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TBN,
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double_sided,
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is_front,
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Nt,
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);
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#endif
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pbr_input.V = fns::calculate_view(mesh.world_position, pbr_input.is_orthographic);
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return tone_mapping(fns::apply_pbr_lighting(pbr_input), view.color_grading);
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}
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