Create a "balloon" that is anchored to the ground by a string and will return to its start position after bumped.

I'd like to have an object that behaves like a helium filled balloon attached to a stiff string that is anchored to the ground. Another way to think about it would be a blade of grass responding to a wind blowing over it. I've tried a spring joint with the y anchor point raised but it works the opposite of what I need, like a rock hanging on a string. A negative Y anchor creates unwanted behavior.

Is a configurable joint the way to go and if so can you please talk me through the steps to create it.

Hrrm, and as a second quick question, are joints expensive on the Iphone?

Thanks, --Goody!

If you got it working like a rock on a string, then you probably only need to invert the gravity for that object to make it work like a balloon instead.

You can uncheck the checkbox on the Rigidbody for "Use Gravity" to make it not use the global gravity force.

Then you can add a Constant Force component and specify a force that goes upwards.