https://github.com/Jondolf/bevy_heavy
Mass properties for Bevy's geometric primitives.
https://github.com/Jondolf/bevy_heavy
bevy game-development geometry mass math physics rust
Last synced: 28 days ago
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Mass properties for Bevy's geometric primitives.
- Host: GitHub
- URL: https://github.com/Jondolf/bevy_heavy
- Owner: Jondolf
- License: apache-2.0
- Created: 2024-02-23T17:43:10.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2025-03-21T00:00:11.000Z (29 days ago)
- Last Synced: 2025-03-21T00:26:05.761Z (29 days ago)
- Topics: bevy, game-development, geometry, mass, math, physics, rust
- Language: Rust
- Homepage: https://docs.rs/bevy_heavy
- Size: 201 KB
- Stars: 11
- Watchers: 2
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE-APACHE
Awesome Lists containing this project
- awesome-bevy - `bevy_heavy`
README
# `bevy_heavy`
[](https://github.com/Jondolf/bevy_heavy#license)
[](https://github.com/Jondolf/bevy_heavy/actions/workflows/ci.yml)
[](https://crates.io/crates/bevy_heavy)
[](https://docs.rs/bevy_heavy)
`bevy_heavy` is a crate for computing mass properties (mass, angular inertia, and center of mass)
for the [geometric primitives] in the [Bevy game engine][Bevy]. This is typically required
for things like physics simulations.
[geometric primitives]: https://docs.rs/bevy/latest/bevy/math/primitives/index.html
[Bevy]: https://bevyengine.org
## Features
- `MassProperties2d` and `MassProperties3d` structs containing the mass, angular inertia, and local center of mass
- Mass property computation for all of Bevy's [geometric primitives]
- Eigensolver for symmetric 3x3 matrices
- Support for `bevy_reflect` and `serde` through the `bevy_reflect` and `serialize` feature flags
## Usage
Mass properties can be computed individually for shapes using the `mass`, `angular_inertia`,
and `center_of_mass` methods:
```rust
use bevy_heavy::{ComputeMassProperties2d, MassProperties2d};
use bevy_math::{primitives::Rectangle, Vec2};
let rectangle = Rectangle::new(2.0, 1.0);
let density = 2.0;
let mass = rectangle.mass(density);
let angular_inertia = rectangle.angular_inertia(mass);
let center_of_mass = rectangle.center_of_mass();
```
You can also compute all mass properties at once, returning `MassProperties2d` for 2D shapes,
or `MassProperties3d` for 3D shapes. This can be more efficient when more than one property is needed.
```rust
let mass_props = rectangle.mass_properties(density);
```
The mass property types have several helper methods for various transformations and operations:
```rust
let shifted_inertia = mass_props.shifted_angular_inertia(Vec2::new(-3.5, 1.0));
let global_center_of_mass = mass_props.global_center_of_mass(Vec2::new(5.0, 7.5));
```
You can also add and subtract mass properties:
```rust
let mass_props_2 = MassProperties2d::new(mass, angular_inertia, Vec2::new(0.0, 1.0));
let sum = mass_props + mass_props_2;
approx::assert_relative_eq!(sum - mass_props_2, mass_props);
```
To support mass property computation for custom shapes, implement `ComputeMassProperties2d`
or `ComputeMassProperties3d` for them.
## Supported `bevy_math` Versions
| `bevy_math` | `bevy_heavy` |
| ----------- | ------------ |
| 0.16 RC | main |
| 0.15 | 0.1 |
## License
`bevy_heavy` is free, open source, and permissively licensed! Except where noted (below and/or in individual files),
all code in this repository is dual-licensed under either:
- MIT License ([LICENSE-MIT](/LICENSE-MIT) or )
- Apache License, Version 2.0 ([LICENSE-APACHE](/LICENSE-APACHE) or )
at your option. This dual-licensing approach is the de-facto standard in the Rust ecosystem,
and there are [very good reasons](https://github.com/bevyengine/bevy/issues/2373) to include both.