direction between two positions?

I need a rotation that corresponds to the direction between to positions, and rez an object with that orientation. Assume for now that the object is already "luckily" oriented, that is, if it needs to point <1,0,0> then the euler rotation <1,0,0> is the correct orientation.

Is this correct:

rotation orientation(vector p1, vector p2)
{
    return (llEuler2Rot(llVecNorm(p2 - p1)));
}

This doesn't seem to work. Is my concept wrong, or should I look elsewhere for the problem?

Thanks!
Jeff

From what I'm seeing here, you are converting a rotational vecotor (p2 - p1) to a rotational vector (llEuler2Rot() ).

Just try:
{
return (llVecNorm(p2 - p1)
}

you dont have Euler representations, you're already inputing rotational vectors, which llVecNorm() already expects. if you are working with eular, do this...

vector eul = <0, 0, 45>; //45 degrees around the z-axis, in Euler form
eul *= DEG_TO_RAD; //convert to radians rotation
rotation quat = llEuler2Rot( eul ); //convert to quaternion

hope that helps

I don't think <1,0,0> is an Euler rotation. It is a vector pointing ahead one unit on the x-axis, right? (If not, ignore me forever.) An Euler is 3 angles, in radians.

Vectors are just 3 floats, grouped together.

Whether they're used for "position" or "velocity" or "impuse" or "force" or "Euler rotation" is up to how the numbers are used.

Not necessarily... When converting an Euler vector to a rotation, if you want the rotation to be equivalent, then you need to pass an Euler rotation.

If you are just passing a direction vector, you will not get the results you expect.

And since llRezObject() expects a quaternion, the OP is asking how to turn a direction vector into a quaternion.

Agreed. I was just making the rather silly point that vectors can be used to hold any arbitrary 3 floats. I frequently use them just to simplify passing a couple of values as a sort-of-array/list-of-3.

<1,0,0> _could_ be used as an EulerRotation, but it's probably not the one the OP wanted -- one that rotates about the X axis by 1 radian =~ 57.3 degrees.

But I was just being a dork. Ignore me now.

OK, I've learned that a normalized vector is not the same thing as a Euler rotation. (Thanks Lee!)

But what's answer to my question? How do I convert two positions into a rotation?

I have positions p1 and p2. What I need is the rotation so that rezzing an object at p1 causes it to point to p2. What's the trick?

Thanks!
Jeff

No idea.. Rotations and quatrathingies always makes my head hurt. The example code on this page might be able to help you, tho..

wow, thanks Meade!

I saw that function entry and dismissed it since it's not what I need at all. But the getRotToPointAxisAt() function looks like may have a clue for me. Thanks!

I'll let y'all know if it works out.

Cheers
Jeff