Trying to understand how NPC spawning works?

adoxa wrote:
[c]longevity[/c] is read, but haven’t checked if it’s used.

There’s also [c]feeling_to_local[/c], all of which are read, but seemingly ignored - it checks for [c]group_reroll_frequency[/c] instead; [c]feeling_to_formation[/c] is processed (but again, unsure if it’s actually used) and definitely causes the others to be ignored.

Intersting, do you have any idea what group_reroll_frequency does? The name sounds as though it could be useful…

For the discussion at large, just to throw another wrench in the works of these guesses and tests, repop_time seems to be relative to density. That is, if you set repop_time to 1000, and your density is 10, encounters spawn slowly. If you still have repop on 1000, but then you set your density to 1000 as well, encounters spawn much much faster.

I haven’t been able to confirm anything but one guess of mine is that repop_time means something like “Time until the area has been repopulated up to the desired density”… however I haven’t been able to figure stuff out for sure which is why I came here hoping to figure it out.

Thanks for everyone who’s helping work this stuff out, I really just want to be able to spawn enemies at reliable intervals so my players don’t get overwhelmed too fast!! I’m hoping to get down to a real understanding of these parameters at some point…

Huh, now that’s very interesting - nice testing! I am indeed overlapping multiple area and patrol path encounters, and with the highest density set at 10, it makes sense that the respawn times are getting divided down to be really fast and unexpected to me.

You say it sums all the relief times together, do you mean both repop time and relief time or specifically just relief time? I’m going to have to do some testing of this on my own now and try and go further with understanding it. Thank you very much for putting me on the right track with this.

I’ve been testing this a bit this morning, removing all overlapping fields to try and just nail down some consistency on timings out of one field with a single encounter and a single permutation within that encounter whose weight is set to 1.

Initially, and at times, things seem to very much reflect what I’d expect with the new knowledge! For instance, with these settings,

density = 10
repop_time = 300
relief_time = 1200

I was expecting an initial spawn to take about 30 seconds, and then reinforcement spawns during that fight to only come in at 120 second intervals. This is exactly what happened at first! I was super excited that the issue might have been cracked completely.

However after further testing there still seems to be things I’m not grasping. After leaving the fight, nothing else spawned for 5+ minutes after, and then after quick loading my SP save I was testing on I couldn’t get anything else to spawn at all for a similar amount of time before giving up.

Further, in a subsequent test I just lowered repop_time to = 1, expecting an instant initial spawn but then for the 1200 relief time to make those reinforcement intervals still be at 120 seconds. This was not the case, and more enemies spawned constantly, seeming to only be running off the repop time here.

I then tried the opposite - repop time left to 300, but relief time turned down to 1. Results got even less like what I expected here. Initial spawn was quick again, at about 20 seconds, but it then took around three minutes and 40 seconds (if I remember right) to spawn a reinforcement enemy. Trying to see if there would be consistency, I killed the initial enemy then stayed in the fight against the reinforcement for another three minutes and 40 seconds - another enemy spawned around this time, which makes the timing seem consistent!

However at that point, another enemy then spawned with seconds afterwards, and then another right after, and another, for a total of four. They seemed to stop spawning rapid fire at this point, but I exploded about 20 to 30 seconds after so I’m not sure what would’ve happened next.
My guess is that relief_time was not in effect until that moment they started rapid-fire spawning, but why? What made that moment when relief_time was called in to spawn things?

So, while initial results seemed to play by the expected rules, things ended up feeling more random again in the end. I’m not sure if it really is some random element to the game, or if it’s just there’s still more math not being understood here - perhaps things are getting divided or multiplied by other things too? If all these values interact and multiply each other in unknown ways, it would make sense why the end results seem so inscrutable and random to me.

The questions I’m left with after this to test further are:

1: Why is it so hard to get consistent timings out of these parameters? Is there a random element designated somewhere else that we don’t know about, or is it just an intended part of these parameters that they’re averages or min and max boundaries rather than exact, static times?

2: What exactly decides when repop_time is in play vs. when relief_time is? Both seem to have their own effects on when an enemy is spawned, but it’s not as straightforward as I expect. Are the seemingly random results actually because the triggers for relief time and repop time to take effect are different to what I think, and are occurring at certain times and contexts in gameplay that I don’t know about?

3: What role does toughness and max_battle_size play in these questions, if any?

4: Are these parameters tracking their values persistently in between loading saves? Is my testing method of quick loading and flying back into the same area part of why these values seem to sometimes misbehave? Does the game need to be fully shut down and restarted to have a good next testing environment?

I’ll keep on testing these things and trying to nail down a controlled and consistent result, but if you Adoxa or anyone else can help figure out the answer to these as well and the knowledge needed to gain that consistency, I’d really appreciate it. I already feel like I’ve got a bit more control now understanding the division element at play with repop time, so that’s been a huge boon already, thanks so much for that.

Yeah sure thing, posting my encounter (bmod_area_fc_x_grp_scouts_1) and the zone (Cheyenne Asteroid Field in Colorado) below

Note we made our own custom fighter classes we’re using for ship_by_class so you’ll want to set those back to whatever vanilla fighter class instead

;Permutations of 1 enemies per spawn

;Perm 0, 1 MFs
[EncounterFormation]
ship_by_class = 1, 1, bmod_sc_heavy_fighters
pilot_job = scout_job
make_class = wanderer
formation_by_class = fighters
behavior = wander
arrival = all, -tradelane, -object_jump_gate
allow_simultaneous_creation = yes
zone_creation_distance = 0
times_to_create = infinite

[Creation]
;1-2 Enemy Cap

;Perm 0, 1-2 MFs
permutation = 0, 1

[zone]
nickname = Zone_Li03_Cheyenne_field
ids_name = 261217
pos = 61910, 0, -39659
rotate = 0, 30, 0
shape = ELLIPSOID
size = 17000, 10000, 30000
property_flags = 64
visit = 32
spacedust = asteroiddust
spacedust_maxparticles = 50
ids_info = 65930
sort = 25
toughness = 10
density = 10
repop_time = 300
max_battle_size = 10
pop_type = lootable_field
relief_time = 1200
encounter = bmod_area_fc_x_grp_scouts_1, 3, 1
faction = fc_x_grp, 1
Music = zone_field_asteroid_rock

Let me know if you’d have rather I just send you the files by the way instead of the relevant snippets

Huh, so you reckon repop_time isn’t related to time at all, but is only a variable in the chance to spawn? That would explain why stuff seems so random - it’s literally always been a chance every 5 seconds, not a cooldown.

Thanks Adoxa, this is terrific to learn. I’ll try following your formula you’ve uncovered and see if things start doing what I’d expect.

Looking at what I have set up now, I can see that in a certain field in my mod, I have Density 16, Repop Time 420 - so without any enemies present, that would be 16 divided by 420 for 0.038 or a 3.8% chance for anything to spawn, every 5 seconds. Thinking about it, this makes a ton of sense why sometimes I get dry runs that seem to last forever, and other times, I just seem to luck out and get constant spawns.

Excellent investigating, thank you so much for saving my sanity here. Is there any way to adjust how often that chance pops? Make it roll every minute or two instead? EDIT: I see now that I can experiment with the Spacepop value you noted, I might try setting it to BELOW_NORMAL, NORMAL, HIGHEST so on and see what happens if anything.

Being able to adjust when the chance is rolled in any way would help smooth out this randomness a lot - having the chance be rolled every minute or thirty seconds, but a lot higher chance to spawn, for instance, would be a lot more reliable to balance with. Same as being able to adjust that per zone/encounter/whatever for different spawn rates, but that’s icing on the cake.

EDIT: Also, lol at the #17 at 17:17 - I’m same timezone as you so I saw it the same 8-)

The 18 ship crash thing is good to know, thanks Skotty.

Adoxa, thank you again for putting the pin on this; I can say now after a week this seems a totally solved issue. Your formula and understanding is bang on target in every way I can confirm, and your offset for the spawning interval heartbeat has worked perfectly.

This has completely changed our mod overnight a thousand times for the better, and we now have perfect control over what spawns when and tons of room for nuance in the future. Thank you so much! It’s the difference between night and day, and I’m super grateful to you for helping us get there.

Just going to pop in the right google search words in case someone’s trying to search engine find this in the future - this is how Freelancer NPC spawning works!