Spawn/despawn bubble with complex trigger

[Sim]

Hi everyone,

 

I am trying to create a bubble-like area with complex trigger that will spawn and despawn certain objects when any aircraft is present at the area. To support more than a single aircraft in the area I need some kind of a counter that gets +1 when someone enters and -1 when someone leaves. The counter should then "trigger" when it reaches 0 - hence, then the area can be unloaded (despawned).

 

I had a look at a couple of existing MP missions, but haven't seen a scheme that can handle multiple aircrafts without issues yet. Does anyone have an idea how to approach this?

 

To illustrate the problem:

 

aircraft A enters alive (counter = 0 + 1 = 1) -> spawn

aircraft B enters alive (counter = 1 + 1 = 2)

aircraft B leaves alive (counter = 2 - 1 = 1)

aircraft A leaves alive (counter = 1 - 1 = 0) -> despawn

 

There is an increment/decrement counter scheme available in the mission blocks sharing topic that seems to work, but it is based on reaching a certain counter value, rather than triggering when empty (at 0).

Edited June 21, 2015 by Sim

[coconut]

Let c1 be a cyclic counter up to N

Let g1 be a 0s timer acting as a gate after c1 (c1 output goes into g1).

 

To increase the counter, increase c1

To decrease the counter, deactivate g1, then increase c1 N-2 times, activate g1, increase c1 once more.

 

Make it so that N is larger than the maximum number of planes in the mission (e.g. 49 if AIs are not used or do not trigger the bubble).

[Sim]

...

 

Nice, just tried this scheme and it seems to work great. Although the bubble is intended for both players and AI, thus the N will need to be somewhat large number. Also, it seems you need to delay the timers at least 20ms before incrementing the counter multiple times. Seeing how I will need to increment them 20+ times, something someday will probably go wrong during this process.

 

Thanks for your help! Still, time to make a suggestion for Mission Editor as this functionality should be definitely available out of the box.

[coconut]

 

 

Also, it seems you need to delay the timers at least 20ms before incrementing the counter multiple times.

Yes, that could be a problem, but not too likely. If people flying in formation leave the bubble flying at 200kph, it's possible a decrease will be missed (or worse bugs if you forget to disable the input "decrease" 0s timer while decreasing) if people fly closer than 60m together (for N=50). That's quite a tight formation, but not unrealistic, I suppose.

 

To handle that problem, one would need to implement a queue of sorts on the input side. Probably doable, but I'm not sure how yet.