A real pain in the axis...

I'm working on an object that needs to be able to rotate to point at a given location, but maintain a specific orientation with respect to the rest of the sim. Essentially I'm trying to orient on a provided roatation while ensuring that relative up/down for the object are correct with respect to the horizontal plane, and that the object's left/right axis is always perpendicular to global up/down. I'm convinced it's a simple matter of extrapolating and recombining euler rotations, but I'm entirely unsure how to go about it.

You are best off keeping to quaternions. If they don't drive you insane, that is.I required institutionalization last I tried to understand them, so I cannot offer further help per doctor's orders.

I'm using quats now. They're not doing what I need them to. Rotating between two positions using quaternions causes the object to rotate around all three local axes. What I *want* it to do is rotate around two specific axes. I first want it to rotate around global up/down so that it's pointed in the compass direction of its target (local forward is at zero elevation with respect to horizontal, pointed at the target), then rotate around local left/right so that it points directly at the target while still maintaining relative up/down in the right quadrants.

I made a teddy bear on a cloud that follows me, and faces towards me but always remains level (the generic pet script I had made him stare at my crotch). I used llLookAt() with something like:

llLookAt(<target.x, target.y, llGetPos().z>...)

Noooooot quite what I need, but thanks. I want full range of motion but not full range of rotation, if that makes any sense. The method you describe essentially clamps rotation to a single plane, making it useful for orienting on the compass position, but not the elevation. I will try using a pair of llLookAt()s to normalize it, but I get the feeling it won't work for a moving target.

I'm not completely understanding what you are shooting for but think the examples under combining rotations should get you closer.

I think I may accidentally have found a solution. It requires redesigning the object so as not to have to worry about roatational anomalies, but I think I'll manage.

how about llSetStatus(STATUS_ROTATE_X,FALSE)?
(or the Y and Z variant)

Redesign how? I'm trying to get a raft to stay rotated horizontally (x/z axes) but allow any vertical/y-axis rotation.

Alfred - just to make sure I'm understanding properly - you want to allow pitch and yaw, but no roll - like the turret of a tank?

If not, can you give us a real-world example of the sort of motion you're looking for?

And Eep - you want pitch only?

No, Ben, *I* want like a tank turret, but more like a floating raft. I have most everything else but free vertical rotation (around up/y/blue axis)...

Pitch and Yaw, no Roll:

vector point_at = the_point_to_aim_position - llGetPos();
vector corrected = point_at;
corrected.z = 0.0;
llRotLookAt(llRotBetween(<1, 0, 0>, corrected) * llRotBetween(corrected, point_at), 0.2, 0.5);

Yaw, noPitch nor Roll:

vector point_at = the_point_to_aim_position - llGetPos();
point_at.z = 0.0
llRotLookAt(llRotBetween(<1, 0, 0>, point_at), 0.2, 0.5);

Jes, I don't think you understand what I want because that's the 3rd script you've posted that does the same thing they ALL do: lock rotation on ALL 3 AXES. I want FREE ROTATION ON the vertical axis but LOCKED rotation on the other axes (horizontal and depth).

Eep, I already have a script that does what you're looking for, but I spent Valentine's day in RL I'll be in tonight (+-noon SL time) to find it.

I don't have one that does Alfred's requirements yet, but I should be able to put one together.

Yaw Only

        vector Offset = llDetectedPos(0) - llGetPos();
        float HalfAngle = llAtan2(Offset.y, Offset.x) / 2.0;
        llSetRot(<0.0, 0.0, llSin(HalfAngle), llCos(HalfAngle)>);

Yaw and Pitch

        vector Offset = llDetectedPos(0) - llGetPos();

        float Yaw = llAtan2(Offset.y, Offset.x) / 2.0;
        float Pitch = -llAtan2(Offset.z, llSqrt(Offset.x*Offset.x + Offset.y*Offset.y)) / 2.0;
        
        float SinYaw = llSin(Yaw);
        float CosYaw = llCos(Yaw);
        float SinPitch = llSin(Pitch);
        float CosPitch = llCos(Pitch);
        
        llSetRot(<-SinPitch*SinYaw, SinPitch*CosYaw, CosPitch*SinYaw, CosPitch*CosYaw>);

Thanks, Ben, but neither of these work either; they just allow all-axis rotation and don't use llRotLookAt, which is what I'm trying to do. When I switch llSetRot to llRotLookAt, the scripts act the same as all the others: restricted all-axis rotation.