I've searched but haven't found anything quite like this.
I think I need a combination of path or surface constraint and kinematics but I'm not sure.
Picture a curved hallway with varying width.
I want a large box to move down the hallway with the right front corner of the box always touching the right wall and the left rear corner always touching the left wall.
How do I do this?
In reality, we are wanting to animate a barge going up a river. We have GPS paths of two opposite corners of the barge. Of course a simple follow path constraint won't work. I need the rear of the barge to swing around to follow the other GPS path.
As you can see from my post below yours I have been wrestling with some rigging issues. I have attached one way to do what you need to do. I'm sure some of the hotshots here will have a more elegant way but sometimes just making it work for a deadline is more important.
Just animate the two point helpers and the boat will follow.
Here are the basics:
Create box (boat)
Create two splines (bow and stern paths)
Create two point helpers
Constrain the helpers to the splines with 'path constraint'
Create a bone with a nub. Don't automatically assign IK.
Put Skin on box
Assign two bones to skin
Select and link bone 1 to point helper 1
Select and link bone 2 to the point helper 2
Apply a 'look-at' constraint to bone 1 and pick point helper 2 as the target.
Go to Envelopes and weight table and make sure all weights for bone 2 verts are 0.000
Animate the point helpers along the paths and the boat will follow
Edit: I went ahead and animated it and attached that too.
Rob Holmes
------------------------------------------------------------------------------------------------------------------------------------------That might do it.
I've never done Bones before so I'll have to look that and rigging up.
I did notice I could get rid of the smaller bone and things still work fine.
Can't wait to give it a try. Might be next week at this point.
Rob Holmes
------------------------------------------------------------------------------------------------------------------------------------------Yeah sorry about that.
For some reason before my first response I didn't scroll down far enough to see your perfectly fine step by step instructions. I edited my post but apparently you saw it before my edit.
I did end up giving it a whirl. My skin is floating away even though I (thought I) applied it while the box was over the bone. I'll mess with it a bit more next week. Fun! Thanks a lot. I appreciate the help.
Rob Holmes
------------------------------------------------------------------------------------------------------------------------------------------Helper one at the front of the boat...and on path.
Helper two at the stern...also on path.
Boat link to helper one...
Helper one with a look at constraint to helper two...align boat as needed.
Should do it!