bevy/examples/shader/custom_vertex_attribute.rs
Joona Aalto 0166db33f7
Deprecate shapes in bevy_render::mesh::shape (#11773)
# Objective

#11431 and #11688 implemented meshing support for Bevy's new geometric
primitives. The next step is to deprecate the shapes in
`bevy_render::mesh::shape` and to later remove them completely for 0.14.

## Solution

Deprecate the shapes and reduce code duplication by utilizing the
primitive meshing API for the old shapes where possible.

Note that some shapes have behavior that can't be exactly reproduced
with the new primitives yet:

- `Box` is more of an AABB with min/max extents
- `Plane` supports a subdivision count
- `Quad` has a `flipped` property

These types have not been changed to utilize the new primitives yet.

---

## Changelog

- Deprecated all shapes in `bevy_render::mesh::shape`
- Changed all examples to use new primitives for meshing

## Migration Guide

Bevy has previously used rendering-specific types like `UVSphere` and
`Quad` for primitive mesh shapes. These have now been deprecated to use
the geometric primitives newly introduced in version 0.13.

Some examples:

```rust
let before = meshes.add(shape::Box::new(5.0, 0.15, 5.0));
let after = meshes.add(Cuboid::new(5.0, 0.15, 5.0));

let before = meshes.add(shape::Quad::default());
let after = meshes.add(Rectangle::default());

let before = meshes.add(shape::Plane::from_size(5.0));
// The surface normal can now also be specified when using `new`
let after = meshes.add(Plane3d::default().mesh().size(5.0, 5.0));

let before = meshes.add(
    Mesh::try_from(shape::Icosphere {
        radius: 0.5,
        subdivisions: 5,
    })
    .unwrap(),
);
let after = meshes.add(Sphere::new(0.5).mesh().ico(5).unwrap());
```
2024-02-08 18:01:34 +00:00

87 lines
2.6 KiB
Rust

//! A shader that reads a mesh's custom vertex attribute.
use bevy::{
pbr::{MaterialPipeline, MaterialPipelineKey},
prelude::*,
reflect::TypePath,
render::{
mesh::{MeshVertexAttribute, MeshVertexBufferLayout},
render_resource::{
AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
VertexFormat,
},
},
};
fn main() {
App::new()
.add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default()))
.add_systems(Startup, setup)
.run();
}
// A "high" random id should be used for custom attributes to ensure consistent sorting and avoid collisions with other attributes.
// See the MeshVertexAttribute docs for more info.
const ATTRIBUTE_BLEND_COLOR: MeshVertexAttribute =
MeshVertexAttribute::new("BlendColor", 988540917, VertexFormat::Float32x4);
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<CustomMaterial>>,
) {
let mesh = Mesh::from(Cuboid::default())
// Sets the custom attribute
.with_inserted_attribute(
ATTRIBUTE_BLEND_COLOR,
// The cube mesh has 24 vertices (6 faces, 4 vertices per face), so we insert one BlendColor for each
vec![[1.0, 0.0, 0.0, 1.0]; 24],
);
// cube
commands.spawn(MaterialMeshBundle {
mesh: meshes.add(mesh),
transform: Transform::from_xyz(0.0, 0.5, 0.0),
material: materials.add(CustomMaterial {
color: Color::WHITE,
}),
..default()
});
// camera
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}
// This is the struct that will be passed to your shader
#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
struct CustomMaterial {
#[uniform(0)]
color: Color,
}
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
"shaders/custom_vertex_attribute.wgsl".into()
}
fn fragment_shader() -> ShaderRef {
"shaders/custom_vertex_attribute.wgsl".into()
}
fn specialize(
_pipeline: &MaterialPipeline<Self>,
descriptor: &mut RenderPipelineDescriptor,
layout: &MeshVertexBufferLayout,
_key: MaterialPipelineKey<Self>,
) -> Result<(), SpecializedMeshPipelineError> {
let vertex_layout = layout.get_layout(&[
Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
ATTRIBUTE_BLEND_COLOR.at_shader_location(1),
])?;
descriptor.vertex.buffers = vec![vertex_layout];
Ok(())
}
}