Get number of agents in a parcel

[KT Kingsley]

Is there a clever way of getting the number of agents in a parcel, other than getting the list length returned by llGetAgentList (AGENT_LIST_PARCEL, []);? I want to do this in an existing script that's already using near the full memory capacity without causing a stack-heap collision.

 

[Fenix Eldritch]

So you basically want to avoid the overhead of a potentially lengthy list returned by llGetAgentList... I suppose you could circumvent that by using a sensor event, since the num_detected parameter can be used as an index to all targets sensed within the sensor sweep. You would need to iterate over num_detected and for each one, pull out the uuid with llDetectedKey and perform some operations on that single user to determine if they're over your land. If the target is over your land, increment a counter.

As for how to determine if an individual avatar is over you land, one approach is to extract the target's position and check that position against llGetLandOwnerAt.

Edit: I forgot that sensors only return the first 16 hits, so this may not be the most robust solution...

Edited November 5, 2019 by Fenix Eldritch

[KT Kingsley]

Also sensors have a range of only 96m.

[Fenix Eldritch]

Yeah, if your parcel is larger than that, that's another limitation

[KT Kingsley]

This is for any parcel, anywhere. If it were just for my parcel, the size of the llGetAgentList return wouldn't be an issue.  

[Rolig Loon]

In the days before llGetAgentList (really not that long ago) , we had to do rather clunky things with drones to gather the information.  I still have a couple of devices in my MP shop that use a drone to scamper around, making overlapping sensor sweeps to gather certain types of information that llGetAgentList cannot.  It's all rather cumbersome, but it works.  You have to make all sorts of allowances for eliminating redundant entries, avoiding no-script areas, watching out for obstacles, and a host of other hazards.  Still, for some applications a drone is a workable solution.

[Nova Convair]

Before firing out a swarm of sensor drones it's alot easier and less resourceful to place a 2nd script which performs the counting - no memory problems then.

I don't know of any other way too.

[Gayngel]

You could use llGetAgentList in another script and link message the list length to your existing script.

[KT Kingsley]

Thanks, everybody. It seems there isn't a clever trick that can be used for this, so brute force it is.

And, Rolig, I remember the time before llSetRegionPos and before llGetAgentList when those drones had to scamper around in ten metre steps and you had to check the conditions for each step if you wanted to be safe.

[Mollymews]

another instance where we would like a function

integer llGetNumberOfAgents( integer scope)

where scope is the same as llGetAgentList()

 

[Erwin Solo]

Yeah, we need a parcel version of http://wiki.secondlife.com/wiki/LlGetRegionAgentCount