mirror of
https://github.com/bevyengine/bevy
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12a2f83edd
# Objective
- This PR aims to make creating meshes a little bit more ergonomic,
specifically by removing the need for intermediate mutable variables.
## Solution
- We add methods that consume the `Mesh` and return a mesh with the
specified changes, so that meshes can be entirely constructed via
builder-style calls, without intermediate variables;
- Methods are flagged with `#[must_use]` to ensure proper use;
- Examples are updated to use the new methods where applicable. Some
examples are kept with the mutating methods so that users can still
easily discover them, and also where the new methods wouldn't really be
an improvement.
## Examples
Before:
```rust
let mut mesh = Mesh::new(PrimitiveTopology::TriangleList);
mesh.insert_attribute(Mesh::ATTRIBUTE_POSITION, vs);
mesh.insert_attribute(Mesh::ATTRIBUTE_NORMAL, vns);
mesh.insert_attribute(Mesh::ATTRIBUTE_UV_0, vts);
mesh.set_indices(Some(Indices::U32(tris)));
mesh
```
After:
```rust
Mesh::new(PrimitiveTopology::TriangleList)
.with_inserted_attribute(Mesh::ATTRIBUTE_POSITION, vs)
.with_inserted_attribute(Mesh::ATTRIBUTE_NORMAL, vns)
.with_inserted_attribute(Mesh::ATTRIBUTE_UV_0, vts)
.with_indices(Some(Indices::U32(tris)))
```
Before:
```rust
let mut cube = Mesh::from(shape::Cube { size: 1.0 });
cube.generate_tangents().unwrap();
PbrBundle {
mesh: meshes.add(cube),
..default()
}
```
After:
```rust
PbrBundle {
mesh: meshes.add(
Mesh::from(shape::Cube { size: 1.0 })
.with_generated_tangents()
.unwrap(),
),
..default()
}
```
---
## Changelog
- Added consuming builder methods for more ergonomic `Mesh` creation:
`with_inserted_attribute()`, `with_removed_attribute()`,
`with_indices()`, `with_duplicated_vertices()`,
`with_computed_flat_normals()`, `with_generated_tangents()`,
`with_morph_targets()`, `with_morph_target_names()`.
87 lines
2.7 KiB
Rust
87 lines
2.7 KiB
Rust
//! A shader that reads a mesh's custom vertex attribute.
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use bevy::{
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pbr::{MaterialPipeline, MaterialPipelineKey},
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prelude::*,
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reflect::TypePath,
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render::{
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mesh::{MeshVertexAttribute, MeshVertexBufferLayout},
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render_resource::{
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AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
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VertexFormat,
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},
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},
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};
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fn main() {
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App::new()
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.add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default()))
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.add_systems(Startup, setup)
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.run();
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}
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// A "high" random id should be used for custom attributes to ensure consistent sorting and avoid collisions with other attributes.
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// See the MeshVertexAttribute docs for more info.
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const ATTRIBUTE_BLEND_COLOR: MeshVertexAttribute =
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MeshVertexAttribute::new("BlendColor", 988540917, VertexFormat::Float32x4);
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/// set up a simple 3D scene
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fn setup(
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mut commands: Commands,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<CustomMaterial>>,
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) {
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let mesh = Mesh::from(shape::Cube { size: 1.0 })
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// Sets the custom attribute
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.with_inserted_attribute(
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ATTRIBUTE_BLEND_COLOR,
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// The cube mesh has 24 vertices (6 faces, 4 vertices per face), so we insert one BlendColor for each
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vec![[1.0, 0.0, 0.0, 1.0]; 24],
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);
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// cube
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commands.spawn(MaterialMeshBundle {
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mesh: meshes.add(mesh),
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transform: Transform::from_xyz(0.0, 0.5, 0.0),
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material: materials.add(CustomMaterial {
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color: Color::WHITE,
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}),
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..default()
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});
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// camera
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commands.spawn(Camera3dBundle {
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transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
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..default()
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});
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}
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// This is the struct that will be passed to your shader
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#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
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pub struct CustomMaterial {
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#[uniform(0)]
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color: Color,
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}
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impl Material for CustomMaterial {
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fn vertex_shader() -> ShaderRef {
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"shaders/custom_vertex_attribute.wgsl".into()
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}
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fn fragment_shader() -> ShaderRef {
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"shaders/custom_vertex_attribute.wgsl".into()
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}
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fn specialize(
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_pipeline: &MaterialPipeline<Self>,
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descriptor: &mut RenderPipelineDescriptor,
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layout: &MeshVertexBufferLayout,
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_key: MaterialPipelineKey<Self>,
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) -> Result<(), SpecializedMeshPipelineError> {
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let vertex_layout = layout.get_layout(&[
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Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
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ATTRIBUTE_BLEND_COLOR.at_shader_location(1),
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])?;
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descriptor.vertex.buffers = vec![vertex_layout];
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Ok(())
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}
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}
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