Rotation between two points

Right, yet again rotations have defeated me!

What I have are two, 2-dimensional points (x and y only, the z co-ordinate is irrelevant). What I want to do is have an object at point A rotated such that its z-axis is aimed at point B, while ensuring that the Y-axis remains pointing up (so the object stays flat).

Point B is actually calculated using a vector that indicates the direction from point A towards point B.

So this is a short answer.

I think you want to use llRot2Axes to get Fwd, Left, and Up. Change them, and use llAxes2Rot to make the new rotation.

lee

Hmm, cheers for the suggestion, but I tried something along those lines earlier, it's the changing the axes part that I don't understand, and random trial and error hasn't worked thus far

vector fwd = llVecNorm(B - A);
vector left = <0.0, 0.0, 1.0> % fwd;
rotation new_rot = llEuler2Rot(<0.0, PI_BY_TWO, PI_BY_TWO>;
new_rot = new_rot * llAxes2Rot(fwd, left, fwd % left);

Oops, didn't realize that the Y-axis was meant to be up. This edit should work.

Awesome, that works perfectly, cheers!