Detecting Whether an Avatar is Facing an Object?

I am using llSensorRepeat to periodically determine the avatars that are close ( within 10m ) of a specified object which contains the script, using PI/6 I can get just the ones that are close and more-or-less directly in front of the object, but is there a way to determine if they are facing the object? I am not sure whether I'd want to use the detected velocity, rotation or whatnot and what target values I'd be looking for.

Any help/tips would be greatly appreciated and if anyone knows of an example script I could look at that'd also be terrific!

Thank you,
Jexx

Well, the forward vector of an avatar can be obtained with llRot2Fwd(llDetectedRot(f)). What you'd then want to do would be to check whether that was in the same direction as the direction to the object i.e. llVecNorm(llGetPos() - llDetectedPos(f)). You can use the dot product to see whether they are in the same direction: forward * dirToObject > 0.0.

Thank you for helping with that, and explaining each step of the calculations - I couldn't have asked for a better response...

Much appreciated!
-Jexx

My pleasure!

Oh, and you might want to be careful with llSensorRepeat - there seems to be a big fat bug with it in the latest update that turns it off if you cross sims or teleport. You should be okay sticking to the same sim as far as I know.

Thanks for the tip - so that bug wouldn't come into play if the script were on a static object that is not attached/moving , right?



Jexx

Lindens doing sim restarts to fix llSensor() problems this might fix the llSensorRepeat() problems too.
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