Does anyone have an avatar watcher script?

Does anyone have a script that will cause an object to rotate on it's z-axis, so that it always faces the nearest av?
It needs to have a long range too, because it is a big object.
I have a script that causes the object to rotate around all 3 axis and face the av, but I only want it to rotate around the z and I cannot figure out how to resrict it to just that.

I am a tyro in LSL so I apologise if the answer seems obvious to those of you with more experience.

Any assistance appreciated.

Thanks

Try putting

llSetStatus(STATUS_ROTATE_X | STATUS_ROTATE_Y, FALSE);

in your script's state_entry() somewhere. Not sure it'll do what you want, but it should stop the object from rotating round the x and y axes.

See http://www.lslwiki.net/lslwiki/wakka.php?wakka=llSetStatus

Thanks for that Innula. I am off to try it now

That is definitely the simplest, easiest solution. If for some reason that isn't sufficient, you could use logic similar to the following to calculate a suitable rotation. Assuming the object's "forward" direction is its local x-axis:

facePosition(vector pos, float rotStrength, float rotTau)
{
   vector posOffset = pos-llGetPos();
   if (llFabs(posOffset.z) > 0.999)
   {
      // Straight up/down.  Any direction should do.
      return;
   }

   vector localY = llVecNorm(<0.0, 0.0, 1.0>%posOffset);
   vector localX = localY%<0.0, 0.0, 1.0>;  // Already a unit vector

   rotation rot = llAxes2Rot(localX, localY, <0.0, 0.0, 1.0>);

   llRotLookAt(rot, rotStrength, rotTau);
}

There's a small optimization that can be done for the cross products in this case, but I think it is slightly more understandable as written above so I'll leave the optimization as an exercise for the reader.

Afraid I cannot get either of those to work, but thanks for your help.
Perhaps I should show what I have so far:

default
{
state_entry()
{
llSensorRepeat("", "", AGENT, 20.0, PI, 0.2);
}

sensor(integer total_number)
{
llLookAt( llDetectedPos(0) + <.0, 0.0, 1.0>, 3.0, 1.0 );
}
}

This makes the object sense the av and turn in response to it, but it does not point right at it and I only want it to rotate around the z axis.
I understand you can use llRotLookAt for this but I am unable to get that working either.

I tried this as suggested:
default
{
state_entry()
{
llSetStatus(STATUS_ROTATE_X | STATUS_ROTATE_Y, FALSE);
llSensorRepeat("", "", AGENT, 20.0, PI, 0.2);
}

sensor(integer total_number)
{
llLookAt( llDetectedPos(0) + <.0, 0.0, 1.0>, 3.0, 1.0 );
}
}

But that made no difference.
Please excuse my ignorance, I am not very experienced at this and am trying to learn.

Any input appreciated

Well, part of your problem at least is the expression 'llDetectedPos(0)+<.0, 0.0, 1.0>'. That will make the object look just [EDIT: ABOVE] the detected avatar. You might want to make it just 'llDetectedPos(0)'. Or store the result of that in a vector variable and then set the z-component of that vector equal to that in the position of your object.

Also, I believe llLookAt() points the local z-axis toward the point mentioned. It is more common that the local x-axis represents "forward". In the Edit window, select the "Local" coordinate frame, then select your object (if it is already selected, select something else and then go back to it). Which color axis is pointing "forward"? If it is red, that's the local x-axis. If it is green, that's the local y-axis. If it is blue, that's the local z-axis. If none of those point "forward", you might need to do some careful adjusting to the rotation to get your object pointed in the right way.

Thanks for the info on axes, that was new to me and is bound to be useful.

I have tried this too:

default
{
state_entry()
{
llSensorRepeat("", "", AGENT, 20.0, PI, 0.2);
llSetStatus(STATUS_ROTATE_X | STATUS_ROTATE_Y, FALSE);
}

sensor(integer total_number)
{
llRotLookAt( llDetectedRot(0) + <0.0, 0.0, 0.0, 0.0>, 3.0, 1.0 );
}
}

Finally got the llRotLookAt command to work but this seems to make the object emulate the av's rotation, so that if you turn your back on it, it turns away from you. If I can stop it doing that I have it, but I am still fiddling with it at this stage.

That is the correct behaviour, it will rotate to the same rotation as the detected rotation.

Try llLookAt instead which will point the z axis at the target. Setting status on the axis will not stop all the axes(who in the heck knew that the plural of axis is axes????) from rotating with this function. Here I am cheating it so that it will point the z axis at the target but at the same elevation.

default {
    state_entry() {
        llSensorRepeat("", "", AGENT, 20.0, PI, 0.2);
    }
    sensor(integer total_number) {
        vector pos = llGetPos();
        vector target = llDetectedPos(0);
        target.z = pos.z;
        llLookAt(target, 3,1);
    }
}

very nice jesse, helps alot to make sure it still looks straight ahead instead of a little up or down depending on the avatar's height, i was struggling with that a couple months ago and never thought of that. i never used the script i was trying work on. i think i got the agent's height and then added 45% of that to the detected z position, so it was roughly pointing at the head but it would still have a little bit of an odd rotation sometimes

edit: a while back someone was trying to get an object to stop "facing down" when it was supposed to look at the avatar. and because as explained above, llLookAt makes the z axis point towards the target, the solution was to make the root invisible or work it into the object another way and rotate it away from the rest of the links, so that when the root was pointing at the target, the rest of the object would face the target as desired

Burning Life or some other celebration a couple of years ago is the only time I have done a display. About 20 clown heads with llLookAt in their noses and threw in a Swarm script. They would all just kind of meander around until some poor soul got too close and then they would all turn and stare at the same time. I never had what you would call a clown phobia but it even got to be kind of creepy to me as I tweaked the scripts

lol nice

Wrote this a while ago, works fine for me.

// This is a script designed to look at the nearest avatar
vector startPos;
vector curPos;
vector oldpos = <0,0,0>;
vector offset;             // offset from Agent
integer iteration;
float rotationRate;       // degrees of rotation per iteration
float sensorInterval = 1;     // seconds between sensor scan.

default
{
    state_entry()
    {
        key id;
        llSensorRepeat( "", id, AGENT, 96, PI, sensorInterval );
        llSetStatus( 1, FALSE );  // turn Physics off.
        llSay (0,"ready...");
    }


    sensor(integer total_number)
    {
        vector position = llDetectedPos(0);
        llLookAt (position,1,.1);
    }
}

Thank you to everyone for their suggestions. Thanks to you , and help from friends in world, I now have several ways to solve this problem, and some increased understanding of of LSL. Maybe one day I will even comprehend it

of course you could creep everyone out with an eye that seems to always look at everyone's screen (black sphere inside a hollow sphere colored on the inside only, inside a hollow white sphere colored on the inside only)

Nice! And maybe make it blink?????
Sounds like a nice project

Hi again.
Thanks to all who contributed to finding a solution for this.
I am using this code and it works great:

default {
state_entry() {
llSensorRepeat("", "", AGENT, 20.0, PI, 0.2);
}
sensor(integer total_number) {
vector pos = llGetPos();
vector target = llDetectedPos(0);
target.z = pos.z;
llLookAt(target, 3,1);
}
}

However, I am now looking for a code to add to the script so that the object will rise by a set amount (say 10m for the sake of example) as it turns toward the nearest av.
Any input whatsoever very much appreciated

*Bump*

setting STATUS_ROTATE_X, STATUS_ROTATE_Y and STATUS_ROTATE_Z only prevents rotation due to physical collisions.

When they are set to false on a physical object, they will only rotate about that axis if told to by a script.

All you need to do is store the vector position of an avatar, and then change the z-value to match the position of the object you're rotating. that way, it will never tilt up. Unless the detected avatar is within the same space the object is in, in which case it may be slightly twitchy, as it tries to point inside itself.


so:

vector here = ZERO_VECTOR;
vector mySize = ZERO_VECTOR;

default {
state_entry(){
llSensorRepeat("", NULL_KEY, AGENT, 96, 4*PI, 0.5);
here = llGetPos();
mySize = llGetScale();
}
on_rez(integer param){
here = llGetPos();
mySize = llGetScale();
}
sensor(integer total){
vector tpos = llDetectedPos(0); // detected objects ordered by their proximity to the sensor

float distance = llVecDist(here, tpos);
if (distance < mySize.x){
tpos *= (distance/mySize.x) * 1.5; // if the object is really close, look at a point behind it
}
tpos.z = here.z; // adjust target altitude to object's center to avoid tilting vertically
llLookAt(tpos, 0.5, 1);
}
}

Look at post #8