Hey all, Im having a hard time working out some rotation math in Xpresso (I'm also having a hard time explaining what I'm after, so please bare with me).

I want to take an object (which is rotated arbitrarily in 3d space) and then "look at it" through an orthogonal plane to get a single 2D rotation value. Effectively flattening 3D space to 2D planar space.

Here's a digram that attempts to explain what I'm going for. Any help would be greatly appreciated! Also, apologies if this makes little sense, I'm struggling to articulate what Im trying to do.