# Link static mesh to a skeletal mesh with physics constraint

Can I link a static mesh to a skeletal mesh using a physics constraint ?

I have skeletal mesh (an animal) that I want to drag or pull around a static mesh (a cart), if I link the two togeather in the blueprint of the character, it lets me compile it, but the cart then “flaps around wildly” behind the animal, its looks broken.

Can I even do what I am trying to do ?

Any thoughts ?

The cart should be the root of the blueprint and not the skeletal mesh. Maybe you did it the other way around?

I did do it the other way round with the animal the root, and the cart being dragged around.

I’ll try it the other way round as you suggest, but how would I get the idea that the animal is dragging the cart ? surely the animal drags, the cart has physics simulation enabled… and then it will behave as if its dragged … no ?

Ok, somehow I managed to misunderstand it as your cart would carry animals around. Anyways, have you checked the “Always Create Physics State” in collisions?

Yes I have that check on both the static mesh and the skeletal mesh.

Ok, what you’re trying to achieve is possible and you seem to do it the correct way. What is the shape of your cart? Does it have turning wheels etc?

The cart has wheels but at the moment they dont turn. So the whole thing scrapes along behind the animal. Except it does it flaps around wildly.

Ok, I’ll try to do it with the third person blueprint. Not exactly an animal but should be the same principle. I’ll let you know if I run into the same issue and can come up with a solution.

Ok, I got exactly the same issue. The problem is that the root is at the same location with the skeletal mesh, so the rotation of the actor swerves the cart around.

The static mesh and the root mesh (skeletal mesh) dont share the same root and I have moved the static mesh far enough away from the skeletal mesh so they dont touch. The cart flips on one location to another in a single frame some times up in the air some times below the ground. It moves so fast its not what you would call animated. It just pings from one random position to the next. also if I turn on similate in the blue print the cart simpy falls straight down …

I see. Maybe it’s jerking around because there is a single constraint acting as the joint. It may behave correctly if you use a bunch of constraints, similar to this guy does with chains: - YouTube

Sorry for the delay in getting back to you, this is solved and my horse and cab are now moving together beautifully.

The problem was that the horse was “inside” the mesh for the cab, so it was bouncing about to “get free”.

Please could you give some info on how you did it?