# Objective
Update a camera's frustum only when needed.
- Maybe a performance gain from not having to compute frusta when not
needed, at the cost of change detection (?)
- Making "fighting" with `update_frusta` less tedious, see
https://github.com/bevyengine/bevy/issues/9077 and
https://discord.com/channels/691052431525675048/743663924229963868/1127566087966433322
## Solution
Add change detection filter for `GlobalTransform` or `T:
CameraProjection` in `update_frusta`, since those are the cases when the
frustum needs to be updated.
## Note
I don't think a migration guide and changelog are needed, but I'm not
100% sure, I could put something like "if you're fighting against
`update_frusta`, you can do it only when there is a change to
`GlobalTransform` or `CameraProjection` now", what do you think? It's
not really a breaking change with a normal use case.
77824b96ff