Obstacle movement

- Points are defined locally; in relation to the shape's origin.
- The position of the shape defines the location of the origin in the
world. When the origin moves, so does the points, since they are defined
in relations to the origin.

- At the moment, the origin gets changed, after creation, to be in the
middle of the shape. This causes a bit of confusion for me, as I'm not
entirely sure how that affects everything, but it is necessarry and
needs to be figured out.