0b5302d96a
# Objective Transparently uses simple `EnvironmentMapLight`s to mimic `AmbientLight`s. Implements the first part of #17468, but I can implement hemispherical lights in this PR too if needed. ## Solution - A function `EnvironmentMapLight::solid_color(&mut Assets<Image>, Color)` is provided to make an environment light with a solid color. - A new system is added to `SimulationLightSystems` that maps `AmbientLight`s on views or the world to a corresponding `EnvironmentMapLight`. I have never worked with (or on) Bevy before, so nitpicky comments on how I did things are appreciated :). ## Testing Testing was done on a modified version of the `3d/lighting` example, where I removed all lights except the ambient light. I have not included the example, but can if required. ## Migration `bevy_pbr::AmbientLight` has been deprecated, so all usages of it should be replaced by a `bevy_pbr::EnvironmentMapLight` created with `EnvironmentMapLight::solid_color` placed on the camera. There is no alternative to ambient lights as resources.
99 lines
3.3 KiB
Rust
99 lines
3.3 KiB
Rust
//! Renders a glTF mesh in 2D with a custom vertex attribute.
|
|
|
|
use bevy::{
|
|
gltf::GltfPlugin,
|
|
prelude::*,
|
|
reflect::TypePath,
|
|
render::{
|
|
mesh::{MeshVertexAttribute, MeshVertexBufferLayoutRef},
|
|
render_resource::*,
|
|
},
|
|
sprite::{Material2d, Material2dKey, Material2dPlugin},
|
|
};
|
|
|
|
/// This example uses a shader source file from the assets subdirectory
|
|
const SHADER_ASSET_PATH: &str = "shaders/custom_gltf_2d.wgsl";
|
|
|
|
/// This vertex attribute supplies barycentric coordinates for each triangle.
|
|
///
|
|
/// Each component of the vector corresponds to one corner of a triangle. It's
|
|
/// equal to 1.0 in that corner and 0.0 in the other two. Hence, its value in
|
|
/// the fragment shader indicates proximity to a corner or the opposite edge.
|
|
const ATTRIBUTE_BARYCENTRIC: MeshVertexAttribute =
|
|
MeshVertexAttribute::new("Barycentric", 2137464976, VertexFormat::Float32x3);
|
|
|
|
fn main() {
|
|
App::new()
|
|
.add_plugins((
|
|
DefaultPlugins.set(
|
|
GltfPlugin::default()
|
|
// Map a custom glTF attribute name to a `MeshVertexAttribute`.
|
|
// The glTF file used here has an attribute name with *two*
|
|
// underscores: __BARYCENTRIC
|
|
// One is stripped to do the comparison here.
|
|
.add_custom_vertex_attribute("_BARYCENTRIC", ATTRIBUTE_BARYCENTRIC),
|
|
),
|
|
Material2dPlugin::<CustomMaterial>::default(),
|
|
))
|
|
.add_systems(Startup, setup)
|
|
.run();
|
|
}
|
|
|
|
fn setup(
|
|
mut commands: Commands,
|
|
asset_server: Res<AssetServer>,
|
|
mut materials: ResMut<Assets<CustomMaterial>>,
|
|
mut images: ResMut<Assets<Image>>,
|
|
) {
|
|
// Add a mesh loaded from a glTF file. This mesh has data for `ATTRIBUTE_BARYCENTRIC`.
|
|
let mesh = asset_server.load(
|
|
GltfAssetLabel::Primitive {
|
|
mesh: 0,
|
|
primitive: 0,
|
|
}
|
|
.from_asset("models/barycentric/barycentric.gltf"),
|
|
);
|
|
commands.spawn((
|
|
Mesh2d(mesh),
|
|
MeshMaterial2d(materials.add(CustomMaterial {})),
|
|
Transform::from_scale(150.0 * Vec3::ONE),
|
|
));
|
|
|
|
commands.spawn((
|
|
Camera2d,
|
|
EnvironmentMapLight {
|
|
intensity: 1.0 / 5.0,
|
|
..EnvironmentMapLight::solid_color(&mut images, Color::WHITE)
|
|
},
|
|
));
|
|
}
|
|
|
|
/// This custom material uses barycentric coordinates from
|
|
/// `ATTRIBUTE_BARYCENTRIC` to shade a white border around each triangle. The
|
|
/// thickness of the border is animated using the global time shader uniform.
|
|
#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
|
|
struct CustomMaterial {}
|
|
|
|
impl Material2d for CustomMaterial {
|
|
fn vertex_shader() -> ShaderRef {
|
|
SHADER_ASSET_PATH.into()
|
|
}
|
|
fn fragment_shader() -> ShaderRef {
|
|
SHADER_ASSET_PATH.into()
|
|
}
|
|
|
|
fn specialize(
|
|
descriptor: &mut RenderPipelineDescriptor,
|
|
layout: &MeshVertexBufferLayoutRef,
|
|
_key: Material2dKey<Self>,
|
|
) -> Result<(), SpecializedMeshPipelineError> {
|
|
let vertex_layout = layout.0.get_layout(&[
|
|
Mesh::ATTRIBUTE_POSITION.at_shader_location(0),
|
|
Mesh::ATTRIBUTE_COLOR.at_shader_location(1),
|
|
ATTRIBUTE_BARYCENTRIC.at_shader_location(2),
|
|
])?;
|
|
descriptor.vertex.buffers = vec![vertex_layout];
|
|
Ok(())
|
|
}
|
|
}
|