https://www.posetteforever.com/viewtopic.php?f=1&t=2672&p=35051#p35051 ----------------------------------- VK Tuesday, 20 March 2007, 11:21 PM Re: Cars With Posable Pedals, Steering Wheel - Like The Cobra ----------------------------------- The phi-flags also define the rotation order of the actor, that is the order of the rotate channels in the .cr2. You can set up the rotation order in the phi or later in the .cr2. Most actors rotate about one axis (like the doors, hood, pedals, etc.). In this case, the rotation order doesn't matter, maybe you even delete the unused rotate channels from the .cr2. The rotation order does matter when the actor uses more than one rotation axis, like the front wheels (to drive and steer). There are two important rules for the order of the rotate channels: 1. Later rotate channels carry the rotation axis of prior rotate channels. 2. The middle (second of three) rotate channel can generate "gimbal lock". A "later channel" is a channel whose code appears later in the .cr2. The "middle" rotate channel is the channel whose code appears after the first and before the third rotate channel. Let's see what this means for the front wheels: We choose the rotation order "xyz". X-rotate revolves the driving wheel. Y-rotate turns the wheel when you are steering. Z-rotate is unused. When you drive and steer, you set both rotations, that is x-rotate (drive) y-rotate (steer). The subsequent steer channel carries the rotation axis of the prior drive channel. When you steer the wheel, the drive rotation axis is carried and points to a new direction. This is what you want. Rule 2 doesn't apply to the front wheels, since we use only 2 rotation axes.