Illustrations of Important Simulation Parameters and Quantities Measured. (a) Sketch of constraint region, an angular region of size 2δ centered at the contacting filopodium's initiation angle θc, which is created by filopodial contact with a guidance cue. The growth cone cannot migrate into the constraint region. (b) A repulsive cue migration sequence where the growth cone migrates with a pre-contact trajectory angle ζpre until it makes filopodial contact with a repulsive cue. The turn angle φ is calculated from the difference between the pre-contact trajectory angle ζpre and the post-contact trajectory angle ζpost.