Anyways, here is the Dubins Path 3d thing. It should be fairly stable now. It cheats a little by shrinking radiuses if it gets into trouble.
Attachments in this post:
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20233211/06/23/image.png
http://fx-td.com/houdiniandchill/wp-content/uploads/discord/20233211/06/23/Dubins_Path_3D.hiplc
