Reconsider our world coordinate system

[philpax]

Our world coordinate system, as described here, is left-handed +x right +y back +z up, with the reasoning that this is similar to Unreal. However:

• Unreal is alone in this particular convention of left-handed z-up: https://twitter.com/freyaholmer/status/1325556229410861056
• Unreal's coordinate system, as far as I can tell, is +x forward, +y right, +z up, which means our scheme is uniquely odd

This leads to a lot of confusion when handling assets from other platforms, as well as generally doing transformations; we don't appear to share a coordinate scheme with any other engines or applications.

Should we change this while we still have the chance?

[ten3roberts]

Another thing to note is that glam assumes and suggests Y up left-hand coordinates for euler angles and conversions. These docs are visible and accessible inside our scripting, but breaks the assumption when used