Change friction behavior in freecam to use smooth nudge #21455

[rossleonardy]

Objective

• Fixes Friction in free_cam controller doesn't account for delta time #21455
• Change the behavior of freecam to use smooth nudge instead of an exponential, per-frame fall off

Solution

• As written, the freecam's velocity decays by half every loop.
• Instead, I used smooth_nudge, which takes the time difference into account so that its behavior isn't depended on the fixed main loop's hz.
• The freecam plugin took a f32 that defaulted to 0.5, and was written so lower numbers would have faster decay. In smooth nudge terms, you could describe this as 64 log 2 at the fixed time step of 64 hz, which is a decay rate of around 44.3.
• I used 40.0 as this seems like an easily understandable default.
• This is a breaking change because now higher numbers (instead of lower numbers) supplied to friction, will increase the decay rate. However, all of the examples that use freecamplugin relied on the default() friction value, and it was only recently added, so I think this is okay.

Testing

• I tested this change in the examples that use freecam;

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[alice-i-cecile]

Thanks!