add third-person view camera & player box

[meyerzinn]

In preparation for physics, it is useful to have an actual player model & a third-person camera to watch.

I'm not sure how physics will integrate quite yet, but I imagine it replaces the rotation slerp with an angular acceleration.

[meyerzinn]

Another consideration for physics: It's a bit weird to have translation on the Player entity but rotation on Body. We could get around this pretty easily by using a cylinder for collision detection instead of an AABB, which makes it rotation-independent.

[Game4all]

Is this good to go as is ? @meyerzinn

[Game4all]

apart from a nit, looks good to me.

[meyerzinn]

@Game4all should be good to go if you approve of the refactors.

[meyerzinn]

Actually, give me a little bit to try and flatten the entity tree and make the integration of physics more obvious/ergonomic.

[Game4all]

@meyerzinn still need a bit of time? (apologies for the ping)

[meyerzinn]

@Game4all no worries, sorry for the delay -- my internship started and I'm working full-time this summer, so I might not have a chance to finish this up. I was working on collision detection in https://github.com/meyerzinn/vx_bevy/tree/collisions2 but didn't quite have time to hammer out the bugs.