I'm working on a simple animation sequence in which three fish swim around in an ellipsis. The fish have already been animated with a swim cycle but when I attach them to a motion path the fish rotates over and under the path (y-axis) rather than rotating laterally (x-axis) to indicate turning while swimming.
I took a video of it to show what I'm talking about.
I tried keying the rotation, but the attributes are all in yellow and won't let me change them. Any suggestions?
It looks like maybe your fish are not oriented correctly before being attached to the motion path.
When we look at a fish, it's obvious to us which end is the 'front'. But Maya can't make that judgment. It assumes whatever part of the object is facing the positive X-axis is the front.
So... make sure your animated fish is facing +X. Freeze transformations so its rotation channels are zeroed. Then attach to the path. This should give you the result you're looking for.
The reason the channels are in yellow is because they are being controlled by something else (in this case, the motion path node). A common strategy to allow yourself extra control over the orientation of a path-animated object is to group it, then attach the group to the path instead of attaching the object directly. The object will inherit the transformations of the group (so it will move and rotate properly along the path), but you will still be free to adjust the position and rotation of the object using its own transform node.