bevy_animation_graph 0.1.0

Animation graph library for the Bevy game engine
Documentation

Crates.io Crates.io CI

Bevy Animation Graph

Motivation

Animation graphs are an essential tool for managing the complexity present in the animation pipelines for modern 3D games. When your game has tens of animations with complex blends and transitions, or you want to generate your animations procedurally from very few keyframes, simple animation clip playback is not enough.

This library aims to fill this gap in the Bevy ecosystem.

Current Features

  • Animation graphs are assets. They can be loaded from asset files, or created in code with an ergonomic API.
  • Available nodes:
    • Animation clip playback.
    • Animation chaining (i.e. play one node after another).
    • Looping.
    • Linear Blending (in bone space).
    • Mirror animation about the YZ plane.
    • Apply a given rotation to some bones in a pose using a bone mask.
    • Arithmetic nodes:
      • F32: Add, Subtract, Multiply, Divide, Clamp.
      • Vec3: Rotation arc.
    • Speed up or slow down animation playback.
    • Animation graph node.
  • Nesting animation graphs as nodes within other graphs.
  • Support for custom nodes written in Rust (with the caveat that custom nodes cannot be serialized/deserialized as assets).
  • Export animation graphs in graphviz .dot format for visualization.
  • Output from graph nodes is cached to avoid unnecessary computations.

Planned Features

In order of priority:

  1. Finite state machines.
  2. Synchronization tracks.
  3. More procedural animation nodes:
    1. Two-bone IK
  4. Graph editor UI tool
  5. Ragdoll and physics integration (inititally bevy_xpbd, possibly rapier later):
    1. Using a bone mask to specify which bones are kinematically driven, and which bones are simulated (i.e. ragdolled)
    2. Pose matching with joint motors (pending on joint motors being implemented in bevy_xpbd, currently WIP)
  6. FABRIK node (?).

Installation

This library is available in crates.io. To install the latest published version run

cargo add bevy_animation_graph

or manually add the latest version to your Cargo.toml.

To install the latest git master, add the following to Cargo.toml

# ...
[dependencies]
# ...
bevy_animation_graph = { git = "https://github.com/mbrea-c/bevy_animation_graph.git" }
# ...

Usage and examples

The documentation in docs.rs contains an introduction of the library and an explanation of a simple animation graph example.

The complete example is also included in examples/fox.rs.

The resulting locomotion graph looks like this: Locomotion graph example And the parameter computation graph: Parameter graph example

A more complex example is included in examples/human.rs.

Contributing

If you run into a bug or want to discuss potential new features, feel free to post an issue, open a PR or reach out to me in Discord (@mbreac in the Bevy discord).

FAQ

Is this ready for production?

No. The library is still in an early stage, and there is likely to be bugs, missing features, performance issues and API breakage as I iron out the kinks in the coming months. However, it has reached the point where it is useful and stable enough that I've started to integrate it into my game, and it may be useful to you for small-ish projects or game jams.

Acknowledgements

Many thanks to Bobby Anguelov for his lectures on animation programming.