Positioning things perpendicular to the ground.

I want to script some cubes to automatically rotate themselves so that they're perpendicular to the ground. I'm assuming that llGroundNormal() is the best thing to use, but my knowledge of vector math is really lacking, and I'm not sure how to convert llGroundNormal()'s results into something llSetRot() can use. Can anyone help?

Some skilled geometer should have a better or more complete answer, but if an answer is urgently needed, I would think that llAxes2Rot() should be able to do this, with a little experimentation.

There's probably loads of ways to calculate it, but here's a single-line solution:

llSetRot(llRotBetween(<0.0, 0.0, 1.0>, llGroundNormal(<0.0, 0.0, 0.0>)));

It works pretty simply by calculating the rotation between global 'up' and the ground's normal, and then applying it as the object's rotation.

That works perfectly, Pedro. Thank you!