I don't know what it's called, or if it's a bone constraint or object constraint, but imagine a dog tied up to a tree. Then the collar won't go past a certain point, which means the dog won't go past a certain point. How do I set up a constraint that says the end point of one hook/bone has to stay within some radius of the start hook/bone? What is that called?
Hi Sid,
There's a few ways to achieve this.
- Limit Distance Constraint (object or bone is the same)
- IK chain w/o stretching
- Spline IK
- and probably a few others.
It's also worth pointing out that you might not even need a constraint. Just don't animate the dog collar (or object etc) past that point.
Sometimes adding limitations actually makes it harder.
eg - Beginner riggers often have the idea of adding a floor constraint (oh that's another one) to the IK legs to stop the feet going through the floor.
But in actuality this creates more work for the animator because they have an extra control that they need to take care of.
It becomes especially hard to walk up or down stairs, or keep the right amount of penetration with the floor to make it look like it's making good contact.
The best solution for that is not to add the constraint at all. If the animator creates bad animation, it's not because there wasn't a floor constraint. It's because they are bad at animating.
Of course, I don't know exactly what you are trying to do but if it's a dog tried to a tree, I would use IK (with stretching) and then animating to look good.
(I've never animated a dog tied to a tree, but I have animated a cute donkey tied to a tree)