bevy/crates
Patrick Walton 8154164f1b
Allow animation clips to animate arbitrary properties. (#15282)
Currently, Bevy restricts animation clips to animating
`Transform::translation`, `Transform::rotation`, `Transform::scale`, or
`MorphWeights`, which correspond to the properties that glTF can
animate. This is insufficient for many use cases such as animating UI,
as the UI layout systems expect to have exclusive control over UI
elements' `Transform`s and therefore the `Style` properties must be
animated instead.

This commit fixes this, allowing for `AnimationClip`s to animate
arbitrary properties. The `Keyframes` structure has been turned into a
low-level trait that can be implemented to achieve arbitrary animation
behavior. Along with `Keyframes`, this patch adds a higher-level trait,
`AnimatableProperty`, that simplifies the task of animating single
interpolable properties. Built-in `Keyframes` implementations exist for
translation, rotation, scale, and morph weights. For the most part, you
can migrate by simply changing your code from
`Keyframes::Translation(...)` to `TranslationKeyframes(...)`, and
likewise for rotation, scale, and morph weights.

An example `AnimatableProperty` implementation for the font size of a
text section follows:

     #[derive(Reflect)]
     struct FontSizeProperty;

     impl AnimatableProperty for FontSizeProperty {
         type Component = Text;
         type Property = f32;
fn get_mut(component: &mut Self::Component) -> Option<&mut
Self::Property> {
             Some(&mut component.sections.get_mut(0)?.style.font_size)
         }
     }

In order to keep this patch relatively small, this patch doesn't include
an implementation of `AnimatableProperty` on top of the reflection
system. That can be a follow-up.

This patch builds on top of the new `EntityMutExcept<>` type in order to
widen the `AnimationTarget` query to include write access to all
components. Because `EntityMutExcept<>` has some performance overhead
over an explicit query, we continue to explicitly query `Transform` in
order to avoid regressing the performance of skeletal animation, such as
the `many_foxes` benchmark. I've measured the performance of that
benchmark and have found no significant regressions.

A new example, `animated_ui`, has been added. This example shows how to
use Bevy's built-in animation infrastructure to animate font size and
color, which wasn't possible before this patch.

## Showcase


https://github.com/user-attachments/assets/1fa73492-a9ce-405a-a8f2-4aacd7f6dc97

## Migration Guide

* Animation keyframes are now an extensible trait, not an enum. Replace
`Keyframes::Translation(...)`, `Keyframes::Scale(...)`,
`Keyframes::Rotation(...)`, and `Keyframes::Weights(...)` with
`Box::new(TranslationKeyframes(...))`, `Box::new(ScaleKeyframes(...))`,
`Box::new(RotationKeyframes(...))`, and
`Box::new(MorphWeightsKeyframes(...))` respectively.
2024-09-23 17:14:12 +00:00
..
bevy_a11y Reflected traits for resources and components: bevy_a11y (#15192) 2024-09-14 01:43:16 +00:00
bevy_animation Allow animation clips to animate arbitrary properties. (#15282) 2024-09-23 17:14:12 +00:00
bevy_app Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_asset bevy_reflect: Add ReflectRef/ReflectMut/ReflectOwned convenience casting methods (#15235) 2024-09-23 16:50:46 +00:00
bevy_audio Reflect derived traits on all components and resources: bevy_audio (#15211) 2024-09-15 14:24:00 +00:00
bevy_color Fix floating point math (#15239) 2024-09-16 23:28:12 +00:00
bevy_core Unify crate-level preludes (#15080) 2024-09-08 17:10:57 +00:00
bevy_core_pipeline Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_derive Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_dev_tools Added HeadlessPlugins (#15203) (#15260) 2024-09-19 16:44:43 +00:00
bevy_diagnostic Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_dylib Generate links to definition in source code pages on docs.rs and dev-docs.bevyengine.org (#12965) 2024-07-29 23:10:16 +00:00
bevy_ecs Allow animation clips to animate arbitrary properties. (#15282) 2024-09-23 17:14:12 +00:00
bevy_encase_derive Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_gilrs Update gilrs requirement from 0.10.1 to 0.11.0 (#15245) 2024-09-16 23:34:04 +00:00
bevy_gizmos Reduce runtime panics through SystemParam validation (#15276) 2024-09-23 16:54:21 +00:00
bevy_gltf Allow animation clips to animate arbitrary properties. (#15282) 2024-09-23 17:14:12 +00:00
bevy_hierarchy move ShortName to bevy_reflect (#15340) 2024-09-21 20:52:46 +00:00
bevy_input Use of deprecated function in example for ButtonInput (#15221) 2024-09-15 15:22:39 +00:00
bevy_internal Spirv passthrough main (adopted, part deux) (#15352) 2024-09-22 14:51:14 +00:00
bevy_log Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_macro_utils Generate links to definition in source code pages on docs.rs and dev-docs.bevyengine.org (#12965) 2024-07-29 23:10:16 +00:00
bevy_math Fix floating point math (#15239) 2024-09-16 23:28:12 +00:00
bevy_mikktspace Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_pbr Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_picking Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_ptr Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_reflect Allow animation clips to animate arbitrary properties. (#15282) 2024-09-23 17:14:12 +00:00
bevy_render Reduce runtime panics through SystemParam validation (#15276) 2024-09-23 16:54:21 +00:00
bevy_scene Rename push children to add children (#15196) 2024-09-16 23:16:04 +00:00
bevy_sprite feature gate picking backends (#15369) 2024-09-22 19:35:15 +00:00
bevy_state Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_tasks Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_text Reflect derived traits on all components and resources: bevy_text (#15229) 2024-09-15 17:21:02 +00:00
bevy_time Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_transform Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_ui feature gate picking backends (#15369) 2024-09-22 19:35:15 +00:00
bevy_utils move ShortName to bevy_reflect (#15340) 2024-09-21 20:52:46 +00:00
bevy_window Allow to expect (adopted) (#15301) 2024-09-20 19:16:42 +00:00
bevy_winit Remove ReceivedCharacter (#15126) 2024-09-10 00:22:06 +00:00