Would I set it up like this tank track tutorial?
I imagine I could set up a chain of bones along a curve, weight paint the belt mesh to the corresponding bones, and set up a few constraints and drivers so they follow the curve when the motor engines rotate? I also imagine I could probably confine a driver to a displacement modifier (vertex grouped to the parts of the curve that are between the motors) to cause the curve to wobble ever so slightly?
I've just switched Blender off for the day so I'll have a crack tomorrow! But boy am I keen to work out how to make things work!
Hang on, I can't add a displacement modifier to a curve. What else could I do to make it wobble in certain spots?
You don't necessarily need to animate the belt, only loop the texture to give the illusion of the belt rotating.
You could use a noise modifier in the graph editor if you want to add some wobble, you only need add a duplicate keyframe at the start and end of the timeline to add the modifier. You may want to consider wobble on the engine itself.
My first thought is a curve to use as a path. Then use hooks to bones of an Armature for the wobble. You can use empties, but then you have to manage all those actions if you later decide to expand your animation. Then use follow path constraint on belt mesh point it to the curve and check follow and offset. With offset you have a 0.00 to 1.00 range 0 being start of curve and 1 being the end of the curve. I personally would setup a driver using a bone, because I like to keep as much of the animation data attached to a rig.
Sorry to flood your post, but I just thought of an even easier way to setup a control bone. Instead of using offset(so uncheck that on the follow path constraint) use the time evaluation. By default the evaluation is 0 to 100. Click the curve/path then under curve/data tab of the properties editor under the path panel change time from 100 to 359. That way it goes from 0(start of curve) to 359(end of curve). Then in your driver you can use:
degrees(var)%360
Where var would be the axis(X, Y, or Z) rotation of the control/driving bone.
Thanks guys! And Dwayne I encourage you to flood my posts, I really appreciate you providing all your knowledge whenever I ask something! I'll have a crack at your tips if I get a moment this evening!