Help me understand "DinoSpawnWeightMultipliers"

[Floyd Collins]

Hello! I want to adjust how dinos spawn on my server. I found about that parameter in Game.ini and want to understand how it works before starting messing with it.
So, for example, let's take our beloved dodo.
First, SpawnLimitPercentage. Looks like every setting in this game (or in UE?) is about multipliers. So 1.0 is "default" spawn rate, and we can control how much of each dino we want.
Theoretically, this line:
DinoSpawnWeightMultipliers=(DinoNameTag="Dodo",OverrideSpawnLimitPercentage=True,SpawnLimitPercentage=2.0,SpawnWeightMultiplier=1.0)
Should allow twice as much dodos in my world, while with this
DinoSpawnWeightMultipliers=(DinoNameTag="Dodo",OverrideSpawnLimitPercentage=True,SpawnLimitPercentage=0.2,SpawnWeightMultiplier=1.0)
There should be 80% less dodos on map, amirite?
However, it's not really obvious what are "default" numbers and how are they stored.
This is nothing more than idea, but i suspect that dino pool is something like (with default settings, ie DinoCountMultiplier=1 and no adjusted weights):
20000 dinos on map
5% dodos, ie 1000 dodos
10% coel, ie 2000 coels
1% rex
0.01% alpha rex (just a very low chance to spawn?)
etc etc etc...
So setting SpawnLimitPercentage=2.0 will allow 2000 dodos. Probably.

Now, for parameter i do not fully understand, it's SpawnWeightMultiplier. Looks like by default there is something close to even spawn distribution, so if i kill, for example, a dodo, somewhere in the world another dodo can spawn. As well as alpha t-rex instead of dodo. But we have somewhat stable number of dodos on island, so with default settings game will try to keep around 1000 dodos on map and dodo will have higher chance of spawning. But if i set something like
DinoSpawnWeightMultipliers=(DinoNameTag="Troodon",OverrideSpawnLimitPercentage=True,SpawnLimitPercentage=2.0,SpawnWeightMultiplier=2.0)
Then troodons will have higher chance of spawning instead of dodos when some dodos are killed. Just a theory, will be happy if someone will be able to confirm/correct me.

Oh, and another question. If i adjust SpawnLimitPercentage and SpawnWeightMultiplier, will i need adjusting every other dino as well, or just buffing/nerfing several dinos will be enough?

Thanks in advance.

[🦊 Hermit]

I think you're pretty close, but I'm not sure it's quite 100% accurate. At least, as far as I understand it.

First of all, I believe spawning is run on a per-node basis, rather than across the entire map. The only creatures which take into account map numbers are titanosaurs, which are limited to three per map. All other dinos are judged by how many have spawned from that particular spawn node, rather than how many are on the entire map at once.

I believe each dino has an unwritten number as to how many of them will spawn from a given node, in relation to other dinos which can spawn from that same node. So for example, dodos are innately more frequently chosen than trikes on beach spawns. And this innate number is equivelant to 100% in the SpawnWeightMultiplier factor.

So if trikes, parasaurs and dodos are all set to 1.0 SpawnWeightMultiplier, they are all at 100% (default) of their potential spawn, and so will spawn in the numbers and ratios seen in the game (I would guess roughly 50% dodos, 25% trikes, 25% parasaurs judging by the number of them I see). Setting one of their SpawnWeightMultipliers to 2.0 will increase that dino's spawn chance to 200%, relative to the other dinos from that node.

The SpawnLimitPercentage, on the other hand, acts like a clamp on spawns for the dino type selected. So if you set a LimitPercentage of 0.25 on dodos, then dodos will only ever be picked to spawn from their nodes a maximum of 25% of the time, irrespective of their spawn weight value. 75% of the time it will choose other dinos that could possibly spawn from that node instead, and which ones it chooses will be based upon the spawn weights of those other dinos.

This means you can guarentee at least a certain number of a particular dino will spawn, by setting their SpawnWeight very high so they will be picked much more frequently than others, but at the same time prevent that dino type from squeezing other spawns out completely because once they hit the limit they will then be disgarded until existing ones are killed/despawn, and other dino types will be spawned instead.

Because it's set up this way, it means that you wouldn't have to adjust every single dino's spawn weight, no. The game calculates all the percentages relative to each other, so while an adjustment in one will increase/reduce spawns, they will not override them completely and prevent other dinos from spawning too.

You could, however, create a massive imbalance if you set the SpawnWeight very high and the SpawnLimit to 1.0 (100%)...this would make the node much more likely to choose that dino type, and not limit itself in spawning that dino type at all, which could conceivably cause it to pick all one dino type until it had filled up all it's slots and no more could spawn from that node without existing dino death/despawn.

(I've edited and rewritten this post far too much, sorry if it's confusing :( )

[Floyd Collins]

Thanks, that was an interesting read.
So generally, slight adjustments of SpawnLimitPercentage (ie down to 0.5 or upto 1.5) should be fine, especially for dinos with relatively small spawn pools (ie rock golems, thylacoleos, squids and so on), if you do not touch SpawnWeightMultiplier parameter.

[🦊 Hermit]

In theory yes. There are some dinos which have a unique, dedicated spawner for their type of dino only (quetz, giga, I believe the thyla might be one of those too, plus a few others) and no other dinos spawn at their node. In which case adjusting the SpawnWeight for those may not make a difference, because that dino will be chosen 100% of the time regardless of it's weight.

In those cases you might need to use the NPCSpawnContainer configs to add those rare dinos to another spawn node too, one which does have other dino types spawning from it, and then limit it in those nodes in order to prevent overspawn.

[Ioritana]

The wiki says that the spawnlimit is a hard limit on the chance the dino will spawn during a spawn calculation. "the type will never be spawned more than SpawnLimitPercentage * 100 percent of the time, regardless of multiplier." This has got to be a complicated calculation.

With just three dinos:
Dodos, weight:6,limit:50%
Dilos, weight:3,limit:20%
Trikes, weight:1,limit:40%

It must calculate it like this: starting with the highest weight, spawn rate is the percentage of total weight (60%) oops, no that's higher than the limit, so it's the limit.
Next highest spawn rate is the percentage of remaining weight (75%) and remaining rate (50%) which is 37.5%, once again too high for the limit, so it's 20%
Then the trike get's the remaining rate of 30%

So the spawnlimit as a limit to spawning rate is a terrible idea when it should just be a population density limit, for example: don't spawn dodos if more than 50% of the creatures in an area are dodos. I mean, it could very well be working that way. Wildcards documentation has been bad before.