What paths can and cannot do

What kind of paths can PathFinder follow?

Paths and path groups work best when the robot generally drives in the same direction and multiple paths continue straight line driving. 

Can Pathfinder generate paths where the robot drives in reverse?

PathFinder paths always go in the forward direction, however, for any path the robot can drive backward by negating the velocities, then exchanging left for right. You should also exchange the left and right encoder values.

Can I have a 90-degree turn in my path?

A 90-degree turn requires a point-turn and is discontinuous in curvature and therefore not possible to create in PathFinder.