Preclusive zone problem

[kmg454]

I was just playing around the motion detect zones to eliminate fast changing sunlight using the preclusive zone.
On the Wiki page it say : The Preclusive zone is processed first; if it is small, and is triggered, the rest of the zone/image will not be processed.

I made a very small Preclusive zone and trigger it while there is an active zone too and there still was an alarm.
On the picture the Preclusive zone is the blue spot, so when we open the door on the right side the Preclusive zone is triggered first and I think this must eliminate other alarms in the active zone.
But I still got alarms because the red active zone is also triggered.
Tried also to add the preclusive zone inside the active zone but seems no difference at all.

Maybe I do not understand how the preclusive zone works and someone can explain it to me.

[rockedge]

interesting. There is a thread talking about detecting if a train is traveling left to right or right to left using active and preclusive zones.
viewtopic.php?f=36&t=26313
I have been experimenting also with using the preclusive zone as you are but I get the same results as you do. I am not sure how the preclusive zone is supposed to work. I would like a better understanding of how it is supposed to function.

[kmg454]

Very frustrating when something is not working as you think it must work, I hope the designers of the Zoneminder zones are reading this tread and will explain how it works.
I think the whole zone setup is very difficult to understand and think there are so much settings that nobody exactly know what he is doing while setting up a zone.

[Pedulla]

Preclusive zones work.
You have to set their sensitivity in the preclusive zone low enough to trigger at least at the same time as, but preferrably before, the active zone is triggered.
One warning though, specific to your scene, make sure the location of the preclusive zone is not located somewhere in the scene where the shadow of an entrant might be cast over the preclusive zone. This would cause no alarm to be triggered.

See the definition here: https://wiki.zoneminder.com/Defining_Zones

Hope that helps.

As to the commentary on the design of ZoneMinder, there are positions available on the development team.

[kmg454]

The wikki page say The Preclusive zone is processed first; if it is small, and is triggered, the rest of the zone/image will not be processed.

In my case it does not work. So when i open the door on the right it triggers first the preclusive zone and then the active zone but I still got an alarm.

In the tread of the train spotting left and right I see also that it is not working, so I guess maybe there is a bug using the preclusive zone.

[suknil]

Try to set "Extend Alarm Frame Count" to 20.

[kmg454]

Try to set "Extend Alarm Frame Count" to 20.

No difference