bevy/crates/bevy_transform
Nicola Papale f32ee63fb1
Fix transform propagation of orphaned entities (#7264)
# Objective

- Fix #7263

This has nothing to do with #7024. This is for the case where the
user opted to **not** keep the same global transform on update.

## Solution

- Add a `RemovedComponent<Parent>` to `propagate_transforms`
- Add a `RemovedComponent<Parent>` and `Local<Vec<Entity>>` to
`sync_simple_transforms`
- Add test to make sure all of this works.

### Performance note

This should only incur a cost in cases where a parent is removed.

A minimal overhead (one look up in the `removed_components`
sparse set) per root entities without children which transform didn't
change. A `Vec` the size of the largest number of entities removed
with a `Parent` component in a single frame, and a binary search on
a `Vec` per root entities.

It could slow up considerably in situations where a lot of entities are
orphaned consistently during every frame, since
`sync_simple_transforms` is not parallel. But in this situation,
it is likely that the overhead of archetype updates overwhelms
everything.

---

## Changelog

- Fix the `GlobalTransform` not getting updated when `Parent` is removed

## Migration Guide

- If you called `bevy_transform::systems::sync_simple_transforms` and
`bevy_transform::systems::propagate_transforms` (which is not
re-exported by bevy) you need to account for the additional
`RemovedComponents<Parent>` parameter.

---------

Co-authored-by: vyb <vyb@users.noreply.github.com>
Co-authored-by: JoJoJet <21144246+JoJoJet@users.noreply.github.com>
2023-04-09 20:53:33 +00:00
..
src Fix transform propagation of orphaned entities (#7264) 2023-04-09 20:53:33 +00:00
Cargo.toml chore: Release (#7920) 2023-03-06 05:13:36 +00:00
README.md transform: remove some dependencies and cleanup 2020-07-10 01:49:23 -07:00

Bevy Transform

This crate is largely a 1:1 port from legion_transform (ecs: legion, math: nalgebra) to bevy (ecs: bevy_ecs, math: glam)