Second Life Forums Archive - Sensors are totally broken

Manuel Paz

Registered User

Join date: 20 Oct 2005

Posts: 10

12-12-2005 20:52

I would like to know whether or not other people have the same exprience as I relatively to sensors in SL. I think they are totally broken. For starters, they don't detect anything across sims, contrary to what the wiki says. Secondly, I get some objects detected which are totally out of range, as when I set range to 96 and get objects detected at more than 200 meters away! Then I get what I call blinking detections: two completely separate sets of objects are detected in alternating events: first one set, then the second one, then the first one again and so on. Some other times I have range set at 96 and yet I cannot detect anything farther than 20 meters away or so.

Huge bugs.

Micheal Moonlight

Registered User

Join date: 4 Sep 2005

Posts: 197

12-12-2005 21:18

can't say i've ever noticed any of these bugs in my scripts using sensors.. radars, moneyballs, home security... the only blip i've ever noticed was when lindens were around invis and it reports there key value but no name. As for across sim, that one might be broken... it seems to be 75% chance it will detect them, if it does it continues to with no problem.. if it dosn't then usually after 4-5 cycles of the sensor it finally does which I tend to think would be normal for cross server/sim detections.

Eloise Pasteur

Curious Individual

Join date: 14 Jul 2004

Posts: 1,952

12-12-2005 23:41

Actually the 200m way is when it DOES detect across sims! llDetectedPos() returns the local co-ordinates. If you're in 250, 250 and they're diagonally away in 5,5 you're actually about 14m apart. But you put those numbers in to llVecDist and you'll get something more list 345m!

But I agree sensing across sim borders is a little dodgy.

Aurael Neurocam

Will script for food

Join date: 25 Oct 2005

Posts: 267

12-13-2005 00:13

Also, sensors in attachments never detect across sims.

I have tested sensors in objects (a follow me script, for example), and those seem to work just fine... as long as you're not in no-script land.

_____________________

Senuka Harbinger

A-Life, one bit at a time

Join date: 24 Oct 2005

Posts: 491

12-13-2005 08:25

as to the 20m range and the "blinking" returns, that's because sensors can only return up to 16 objects/avatars, anything more than that is ignored. what's happening in those cases is that you have 16 returns within the 20m limit, or the two that are blinking are exactly the same distance away (or switching distances) and you have already detected 15 objects/avatars, so your 1st ping (sensor) will return one of them, and the 2nd ping will return the other.

_____________________

My SLExchange shop

Typos are forgiven; desecrating the english language with reckless abandon and necrophilic acts is not.

The function is working perfectly fine. It's just not working the way you wanted it to work.

Travis Lambert

White dog, red collar

Join date: 3 Jun 2004

Posts: 2,819

12-13-2005 08:35

From my experience in testing, both in 1.7 and on the 1.8 Preview grid - Sensor doesn't appear to work across sim boundaries.

The wiki is currently incorrect on this behavior.

_____________________

------------------
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The Shelter is a non-profit recreation center for new residents, and supporters of new residents. Our goal is to provide a positive & supportive social environment for those looking for one in our overwhelming world.

Haravikk Mistral

Registered User

Join date: 8 Oct 2005

Posts: 2,482

12-13-2005 09:15

The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate?
So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5).

Lex Neva

wears dorky glasses

Join date: 27 Nov 2004

Posts: 1,361

12-13-2005 10:17

From: Haravikk Mistral

The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate?
So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5).

Actually, in my experience with this bug, that's EXACTLY how it works. I've been fiddling around with a script that detects avatars and plots them on a little map, and sometimes for no reason I can see, it detects avatars over 200m away and in another sim entirely. The dots I rez show up way far way on my map, making me believe that llSensor's feeding me data relative to the sim I'm in, even when objects are in another sim: I'm getting values over 256 and under 0.

This means that sometimes, even when there are well over 16 avs near me, I see up to 3 or 4 avs in neighboring sims, and on one occasion on the sim diagonally conencted to the one I was in. I explore, and it turns out that those people are most definitely in those sims at the positions sensed.

I've reported this bug...

Harris Hare

Second Life Resident

Join date: 5 Nov 2004

Posts: 301

12-13-2005 12:34

I've been using sensors a lot lately and I haven't noticed any odd detections that I'm aware of. I am aware of the sensor not detecting across sim borders (which is something that actually works to my advantage).

If it's any help, I only scan for AGENT(s) at 96m TWO_PI. I don't scan in an attachment and I only use llSensor (not llSensorRepeat).

Tezkat Murakami

Ebil Genius

Join date: 25 Sep 2005

Posts: 12

12-13-2005 13:46

From: Haravikk Mistral

The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate?
So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5).

Um... that is how it works now. The problem with cross-sim detection is not the functions themselves but the fact that neighbouring sims don't talk to each other very often. What you usually see when running cross-border sensors is a 5 second or so cycle of no_sensor events (or simply failure to detect objects/agents on the other side, if scanning for multiple targets) followed by a hit. Unfortunately, the first ping is sometimes (often?) outside of this narrow communications window, so applications based on llSensor will have more problems with sim borders than ones with repeating sensors.

Sensors are totally broken
Manuel Paz Registered User Join date: 20 Oct 2005 Posts: 10	12-12-2005 20:52 I would like to know whether or not other people have the same exprience as I relatively to sensors in SL. I think they are totally broken. For starters, they don't detect anything across sims, contrary to what the wiki says. Secondly, I get some objects detected which are totally out of range, as when I set range to 96 and get objects detected at more than 200 meters away! Then I get what I call blinking detections: two completely separate sets of objects are detected in alternating events: first one set, then the second one, then the first one again and so on. Some other times I have range set at 96 and yet I cannot detect anything farther than 20 meters away or so. Huge bugs.
Micheal Moonlight Registered User Join date: 4 Sep 2005 Posts: 197	12-12-2005 21:18 can't say i've ever noticed any of these bugs in my scripts using sensors.. radars, moneyballs, home security... the only blip i've ever noticed was when lindens were around invis and it reports there key value but no name. As for across sim, that one might be broken... it seems to be 75% chance it will detect them, if it does it continues to with no problem.. if it dosn't then usually after 4-5 cycles of the sensor it finally does which I tend to think would be normal for cross server/sim detections.
Eloise Pasteur Curious Individual Join date: 14 Jul 2004 Posts: 1,952	12-12-2005 23:41 Actually the 200m way is when it DOES detect across sims! llDetectedPos() returns the local co-ordinates. If you're in 250, 250 and they're diagonally away in 5,5 you're actually about 14m apart. But you put those numbers in to llVecDist and you'll get something more list 345m! But I agree sensing across sim borders is a little dodgy.
Aurael Neurocam Will script for food Join date: 25 Oct 2005 Posts: 267	12-13-2005 00:13 Also, sensors in attachments never detect across sims. I have tested sensors in objects (a follow me script, for example), and those seem to work just fine... as long as you're not in no-script land. _____________________
Senuka Harbinger A-Life, one bit at a time Join date: 24 Oct 2005 Posts: 491	12-13-2005 08:25 as to the 20m range and the "blinking" returns, that's because sensors can only return up to 16 objects/avatars, anything more than that is ignored. what's happening in those cases is that you have 16 returns within the 20m limit, or the two that are blinking are exactly the same distance away (or switching distances) and you have already detected 15 objects/avatars, so your 1st ping (sensor) will return one of them, and the 2nd ping will return the other. _____________________ My SLExchange shop Typos are forgiven; desecrating the english language with reckless abandon and necrophilic acts is not. The function is working perfectly fine. It's just not working the way you wanted it to work.
Travis Lambert White dog, red collar Join date: 3 Jun 2004 Posts: 2,819	12-13-2005 08:35 From my experience in testing, both in 1.7 and on the 1.8 Preview grid - Sensor doesn't appear to work across sim boundaries. The wiki is currently incorrect on this behavior. _____________________ ------------------ The Shelter The Shelter is a non-profit recreation center for new residents, and supporters of new residents. Our goal is to provide a positive & supportive social environment for those looking for one in our overwhelming world.
Haravikk Mistral Registered User Join date: 8 Oct 2005 Posts: 2,482	12-13-2005 09:15 The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate? So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5).
Lex Neva wears dorky glasses Join date: 27 Nov 2004 Posts: 1,361	12-13-2005 10:17 From: Haravikk Mistral The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate? So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5). Actually, in my experience with this bug, that's EXACTLY how it works. I've been fiddling around with a script that detects avatars and plots them on a little map, and sometimes for no reason I can see, it detects avatars over 200m away and in another sim entirely. The dots I rez show up way far way on my map, making me believe that llSensor's feeding me data relative to the sim I'm in, even when objects are in another sim: I'm getting values over 256 and under 0. This means that sometimes, even when there are well over 16 avs near me, I see up to 3 or 4 avs in neighboring sims, and on one occasion on the sim diagonally conencted to the one I was in. I explore, and it turns out that those people are most definitely in those sims at the positions sensed. I've reported this bug...
Harris Hare Second Life Resident Join date: 5 Nov 2004 Posts: 301	12-13-2005 12:34 I've been using sensors a lot lately and I haven't noticed any odd detections that I'm aware of. I am aware of the sensor not detecting across sim borders (which is something that actually works to my advantage). If it's any help, I only scan for AGENT(s) at 96m TWO_PI. I don't scan in an attachment and I only use llSensor (not llSensorRepeat).
Tezkat Murakami Ebil Genius Join date: 25 Sep 2005 Posts: 12	12-13-2005 13:46 From: Haravikk Mistral The simplest fix to cross-sim sensors (and other events like a touch) then would be to have the llDetectedPos() functions return values larger than 256 or less than 0 where appropriate? So if my sensor is at (0,5) in one sim, and the detected person is at (0,250) in their sim, it would give me their position as (0,-5). Um... that is how it works now. The problem with cross-sim detection is not the functions themselves but the fact that neighbouring sims don't talk to each other very often. What you usually see when running cross-border sensors is a 5 second or so cycle of no_sensor events (or simply failure to detect objects/agents on the other side, if scanning for multiple targets) followed by a hit. Unfortunately, the first ping is sometimes (often?) outside of this narrow communications window, so applications based on llSensor will have more problems with sim borders than ones with repeating sensors.

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Sensors are totally broken