Hi...
Unfortunately you can't use 3D motions with quadrupeds.
However, to simulate your character walking forward, try switching to 3D View from the top toolbar and then move your character backwards along the Z-Axis so it appears further in the distance. Then simply move to the required keyframe on the time line and repeat the step, this time moving your character forward on the Z-Axis. Doing this when combined with a simple walk animation will make it look like your character is walking towards the camera.
Peter
Forum Administrator
www.reallusion.com