http://www.graphicall.org/ftp/ideasman42/curve_auto_twist.png Access next to the "3D" edit button. details... - open curves use the first points orientation and minimize twist for each new segment. - cyclic curves calculate the least twist in both directions and blend between them - AxisAngleToQuat replaced inline code. - Notice the model on the right now has more even corners. added Vec3ToTangent to arithb.c.