bevy/crates/bevy_transform
Rostyslav Toch d30391b583
Optimize transform propagation (#14373)
# Objective

- Optimize the `propagate_recursive` function in the transform system to
reduce CPU usage.
- Addresses performance bottleneck in transform propagation, especially
for scenes with complex hierarchies.

## Solution

- Avoided unnecessary cloning of `global_transform` when creating the
tuple in the `propagate_recursive` function.
- Used `as_ref()` method on `Mut<GlobalTransform>` when passing it to
the recursive call, avoiding an extra dereference.
- These changes significantly reduced the CPU usage of this function
from 4.91% to 1.16% of self function time.

## Testing

- Performance testing was conducted using the Hotspot GUI tool,
comparing CPU usage before and after the changes.
- `cargo run --release --example many_foxes`
- Tested on Fedora Linux.
---

## Showcase

Here are the PERF GUI results showing the improvement in CPU usage:

### Before

![image](https://github.com/user-attachments/assets/b5c52800-710b-4793-bf75-33e3eb1d2083)

### After

![image](https://github.com/user-attachments/assets/654a4feb-924c-41c8-8ff9-3a1027bd28b9)

As we can see, the CPU usage for the `propagate_recursive` function has
been reduced from 4.91% to 1.16%, resulting in a significant performance
improvement.

## Migration Guide

This change does not introduce any breaking changes. Users of the Bevy
engine will automatically benefit from this performance improvement
without needing to modify their code.
2024-07-22 18:53:16 +00:00
..
src Optimize transform propagation (#14373) 2024-07-22 18:53:16 +00:00
Cargo.toml Bump Version after Release (#14219) 2024-07-08 12:54:08 +00:00
README.md Add README.md to all crates (#13184) 2024-05-02 18:56:00 +00:00

Bevy Transform

License Crates.io Downloads Docs Discord

This crate contains types and functions associated with the Transform component.