Question

I have a model in space in Unity (C#), and this model is skydiving. It’s always facing the ground, but X and Z rotate. The effect I’m going for is that when I rotate, rather than rotating around the model center, I rotate around a point a set distance directly to the models left or right, depending. I already have the rotation logic, but what I don’t have is how to determine the world position of “X pixels to the right” since rotation changes what is right/left. For example:

When I start, left is -1,0; right is +1,0 x
I rotate around left 45 degrees. left is still -1,0. But now my position is (~) -.7,.7. And since my “left” is still pointed at -1,0, “right is suddenly pointing at (~) 0,1.4

So how do I determine, given the model’s Vector3 position, the model’s X,Z rotation, and the offset, where “to the left” and “to the right” are.

For those visual types, Just Cause 2 did it right (though it can be difficult to tell sometimes):
http://youtu.be/C6H3PPfx1KI?t=2m

Thanks, everyone.

Answer 1

It sounds like you just want to do the following:

1. Assign left / right coordinates in model space left = (-1, 0, 0), right = (1, 0, 0).
2. Transform rotation point(s) from model space to world space (e.g. worldLeft = transform.TransformPoint(left)).
3. Rotate around world space point (transform.RotateAround(worldLeft, Vector3.up, speed * Time.deltaTime)).