Yes, that's what I mean by resetting them. Here's what you need to do to reproduce it in the demo scene: 1) In the hierarchy, choose the face-shaped spline. Then in inspector, uncheck the "Loop". 2) Then unfold the spline in the hierarchy to expose all its points. Then choose all its points and do the same thing: set the Z positions into 0. This will make all the points in one plane. 3) Now, select the first point, and then set the "Preceding Control Point" and "Following Control Point" into (0,0,0) in the inspector window. 4) Back to hierarchy, select "CubeConstantSpeed". Then set the "Travel Mode" into "Ping Pong". This step is not necessary but make things easier to see the problem later. 5) Now start playing. I hope I describe the step correctly. Sorry for the late reply and thank you for your quick reply.