# Objective
- Closes#9384.
## Solution
- Make the movement speed of the `CameraController` adjustable with the
scroll wheel as mentioned
[here](https://github.com/bevyengine/bevy/issues/9384#issuecomment-1668957931).
The speed use an exponential progression (10% increase per scroll tick
by default) to allow adapting the speed to different scales.
- For the `scene_viewer` example, make the default speed proportional to
the size of the scene using what's computed for the default camera
placement. This gives a good enough default to fly over the scene from
the outside. I don't think there's a good way to get a default speed
fitting for all scenes since some are meant to be viewed from outside
while other are traversable environments.