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https://github.com/bevyengine/bevy
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54006b107b
# Objective A big step in the migration to required components: meshes and materials! ## Solution As per the [selected proposal](https://hackmd.io/@bevy/required_components/%2Fj9-PnF-2QKK0on1KQ29UWQ): - Deprecate `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle`. - Add `Mesh2d` and `Mesh3d` components, which wrap a `Handle<Mesh>`. - Add `MeshMaterial2d<M: Material2d>` and `MeshMaterial3d<M: Material>`, which wrap a `Handle<M>`. - Meshes *without* a mesh material should be rendered with a default material. The existence of a material is determined by `HasMaterial2d`/`HasMaterial3d`, which is required by `MeshMaterial2d`/`MeshMaterial3d`. This gets around problems with the generics. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, previously nothing was rendered. Now, it renders a white default `ColorMaterial` in 2D and a `StandardMaterial` in 3D (this can be overridden). Below, only every other entity has a material:   Why white? This is still open for discussion, but I think white makes sense for a *default* material, while *invalid* asset handles pointing to nothing should have something like a pink material to indicate that something is broken (I don't handle that in this PR yet). This is kind of a mix of Godot and Unity: Godot just renders a white material for non-existent materials, while Unity renders nothing when no materials exist, but renders pink for invalid materials. I can also change the default material to pink if that is preferable though. ## Testing I ran some 2D and 3D examples to test if anything changed visually. I have not tested all examples or features yet however. If anyone wants to test more extensively, it would be appreciated! ## Implementation Notes - The relationship between `bevy_render` and `bevy_pbr` is weird here. `bevy_render` needs `Mesh3d` for its own systems, but `bevy_pbr` has all of the material logic, and `bevy_render` doesn't depend on it. I feel like the two crates should be refactored in some way, but I think that's out of scope for this PR. - I didn't migrate meshlets to required components yet. That can probably be done in a follow-up, as this is already a huge PR. - It is becoming increasingly clear to me that we really, *really* want to disallow raw asset handles as components. They caused me a *ton* of headache here already, and it took me a long time to find every place that queried for them or inserted them directly on entities, since there were no compiler errors for it. If we don't remove the `Component` derive, I expect raw asset handles to be a *huge* footgun for users as we transition to wrapper components, especially as handles as components have been the norm so far. I personally consider this to be a blocker for 0.15: we need to migrate to wrapper components for asset handles everywhere, and remove the `Component` derive. Also see https://github.com/bevyengine/bevy/issues/14124. --- ## Migration Guide Asset handles for meshes and mesh materials must now be wrapped in the `Mesh2d` and `MeshMaterial2d` or `Mesh3d` and `MeshMaterial3d` components for 2D and 3D respectively. Raw handles as components no longer render meshes. Additionally, `MaterialMesh2dBundle`, `MaterialMeshBundle`, and `PbrBundle` have been deprecated. Instead, use the mesh and material components directly. Previously: ```rust commands.spawn(MaterialMesh2dBundle { mesh: meshes.add(Circle::new(100.0)).into(), material: materials.add(Color::srgb(7.5, 0.0, 7.5)), transform: Transform::from_translation(Vec3::new(-200., 0., 0.)), ..default() }); ``` Now: ```rust commands.spawn(( Mesh2d(meshes.add(Circle::new(100.0))), MeshMaterial2d(materials.add(Color::srgb(7.5, 0.0, 7.5))), Transform::from_translation(Vec3::new(-200., 0., 0.)), )); ``` If the mesh material is missing, a white default material is now used. Previously, nothing was rendered if the material was missing. The `WithMesh2d` and `WithMesh3d` query filter type aliases have also been removed. Simply use `With<Mesh2d>` or `With<Mesh3d>`. --------- Co-authored-by: Tim Blackbird <justthecooldude@gmail.com> Co-authored-by: Carter Anderson <mcanders1@gmail.com>
74 lines
2.7 KiB
Rust
74 lines
2.7 KiB
Rust
//! Skinned mesh example with mesh and joints data loaded from a glTF file.
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//! Example taken from <https://github.com/KhronosGroup/glTF-Tutorials/blob/master/gltfTutorial/gltfTutorial_019_SimpleSkin.md>
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use std::f32::consts::*;
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use bevy::{math::ops, prelude::*, render::mesh::skinning::SkinnedMesh};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.insert_resource(AmbientLight {
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brightness: 750.0,
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..default()
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})
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.add_systems(Startup, setup)
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.add_systems(Update, joint_animation)
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.run();
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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// Create a camera
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commands.spawn(Camera3dBundle {
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transform: Transform::from_xyz(-2.0, 2.5, 5.0)
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.looking_at(Vec3::new(0.0, 1.0, 0.0), Vec3::Y),
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..default()
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});
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// Spawn the first scene in `models/SimpleSkin/SimpleSkin.gltf`
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commands.spawn(SceneBundle {
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scene: asset_server
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.load(GltfAssetLabel::Scene(0).from_asset("models/SimpleSkin/SimpleSkin.gltf")),
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..default()
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});
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}
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/// The scene hierarchy currently looks somewhat like this:
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///
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/// ```text
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/// <Parent entity>
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/// + Mesh node (without `Mesh3d` or `SkinnedMesh` component)
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/// + Skinned mesh entity (with `Mesh3d` and `SkinnedMesh` component, created by glTF loader)
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/// + First joint
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/// + Second joint
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/// ```
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///
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/// In this example, we want to get and animate the second joint.
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/// It is similar to the animation defined in `models/SimpleSkin/SimpleSkin.gltf`.
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fn joint_animation(
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time: Res<Time>,
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parent_query: Query<&Parent, With<SkinnedMesh>>,
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children_query: Query<&Children>,
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mut transform_query: Query<&mut Transform>,
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) {
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// Iter skinned mesh entity
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for skinned_mesh_parent in &parent_query {
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// Mesh node is the parent of the skinned mesh entity.
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let mesh_node_entity = skinned_mesh_parent.get();
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// Get `Children` in the mesh node.
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let mesh_node_children = children_query.get(mesh_node_entity).unwrap();
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// First joint is the second child of the mesh node.
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let first_joint_entity = mesh_node_children[1];
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// Get `Children` in the first joint.
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let first_joint_children = children_query.get(first_joint_entity).unwrap();
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// Second joint is the first child of the first joint.
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let second_joint_entity = first_joint_children[0];
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// Get `Transform` in the second joint.
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let mut second_joint_transform = transform_query.get_mut(second_joint_entity).unwrap();
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second_joint_transform.rotation =
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Quat::from_rotation_z(FRAC_PI_2 * ops::sin(time.elapsed_seconds()));
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}
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}
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