I was reading back over the road map and was wondering if you have considered a mechanic for creating spawner cores for mobs that don't traditionally appear with spawners? It seems like with the proposed spawner extractor it would only be possible to make blaze, zombie, and skeleton powered spawners in most cases.

I'm thinking that some system where mobs are sucked in and compressed fits the theme of the mod very well.

First, an Air Grate in Vacuum mode is used to suck mobs into a special mob compressor. This might be a new multiblock or simply a special interaction between a standard pressure chamber interface and an air grate. A minimum number of mobs is required in order to produce the basic mob essence. Let's say you need 9 mobs to get your initial essence. This can't be used to reliably make a spawner yet, and indeed could even contain the essence of multiple mob types if you're not careful in feeding it. This essence would have a purity rating by mob type. Feeding it only the initial 9 mobs results in a very low purity essence which can be increased in this step up to some threshold by feeding it more mobs. Let's say it starts at 10% and can go up to 50% total purity with this method.

Next, this essence needs to be further purified. This can be done using the UV light box. It will bring up the purity to 100% total but it won't remove types. So if I had initially created an essence that contained 25% zombie and 25% skeleton, the resulting core would be 50% zombie and 50% skeleton after exposure to the light box. This means that when I go to make a spawner out of it, it's got a 50% chance of actually producing the type that I want. If I hadn't purified it at all, instead I'd have a 25% chance of either mob and a 50% chance of complete failure.

The air cost for this purification step should also be substantial. Meaning it would be smart to get a lot of mobs together for the initial step to save on air, but if that's not possible due to the mob being very rare (witches as a prime example) then you can at least still make a pure spawner with a very limited initial input at the cost of more air.

So let's say I actually want a witch spawner. I'd have to actively filter the mobs I'm feeding it in the first step to ensure it only gets witches in. Easily done with drones. Then, once I've fed it enough, the essence is fed through the light box and finally I've got my 100% pure witch core that can be used to produce the air powered spawner.

This wouldn't necessarily replace what you've proposed already, but simply offer an involved mechanic for creating spawners for other mob types. If all you want is a blaze spawner, for instance, you'd be better off extracting a pure core out of an existing vanilla spawner and skip the hassle of compression/purification.

Sorry, haven't had time to comment on this in the last few days, been busy porting to 1.16...

Haven't forgotten about this though, I will be back to continue the discussion!

No trouble at all. Just random ideas I had late at night. :D Good luck with 1.16! Hope we can all kind of find a place to settle for a while though. Feels like modding is moving at breakneck speeds here recently

So, there's an alpha out for 1.16.1 (yay!), and while I think about adding biofuels to it, let's have a chat about this :)

I do like these ideas, but I'm not sure about adding a whole new multiblock for it. How about a portable mob-absorption device (think Ghostbusters), where you go out adventuring for your rare mob, and when you find it, you deploy your Mob Absorber (or whatever it's called). The Mob Absorber would need to be prepared by giving it negative pressure (say, better than -0.75 bar), and be good for X number of mobs before you need to take it back and "re-vacuum" it.

When deployed, it would suck in all nearby mobs, converting them to the Spawner Essence fluid you discussed above. This fluid might be tricky to implement, but FluidStacks can have NBT so it could work. Mixing stacks of this fluid would need to combine the proportions properly, and might need a custom fluid tank to do...

Also, not sure about using the UV Light Box to purify - it's only set up to expose PCB's right now, and not really set up for fluids at all. I think a new machine might be better for that.

But here's a second idea: back to the original Spawner Extractor idea, what if it left behind an empty spawner cage? And had a "reverse" mode that sucked in the nearest mob, creating a spawner of that mob type? Then you could run the Extractor in standard mode again to extract the spawner core...

I really like the ghost busters block, actually. It's got a very cool theme element to it. If you could do the big bright light when it's open too, it would have a nice wow factor to using it.

It wouldn't be too difficult to simply pack up a compressor and a vacuum pump and carry them all around for use on the go, either. No worse than using a gas lift currently to pump oil. Just set it up temporarily and lead mobs over to it.

As for the mob essence, I wasn't actually thinking of it being a liquid. Just a regular old item so you can more easily store the nbt on it and adjust it as more mobs get absorbed. That would make it easier to run through the UV light box too. Although, that purification idea was primarily born from your comment once-upon-a-time of looking for more uses for the UV light box.

The empty spawner cage might work too, but I think it would have to be a custom block. An empty vanilla spawner defaults to spawning pigs, I think.

I'm also kind of thinking of skyblock packs. If a vanilla spawner is always a requirement to get started, then there may well be no way to access PNC spawning. Sure, a pack author could make that happen, but I feel if you're going to get into mob spawning, it should be on your own terms. Interface with Vanilla, yes, but not be beholden to it.

So let's say an empty Mob Cage can be crafted and we have the original Spawner Extractor with both push and pull mode.

Extract mode, as you outlined, would suck the mob out of an existing vanilla spawner. This should probably destory the vanilla spawner upon completion so you don't leave a pig spawner behind.

Insert mode then only works with the crafted PNC Mob Cage. I do think this should still require multiple mobs, even if the purification idea is abandoned. This way it takes a little more planning and effort to capture rarer mobs like wither skeletons, witches, and vindicators. Once enough mobs are sucked in, then you have to reverse it to get your spawner core back out, going through the same battle as with a vanilla spawner.

I could see that working quite nicely.

One concern I had with the battle mode, however, is how easy it would be to cheese it. Since the only requirements are that the player remain close and there are no mobs in the area, one could simply light up the room. If you work around that by saying the spawner must be active (or even trigger progress off of spawn cycles) then the player could simply dig a hole and let them fall out of range.

Perhaps the battle should be a little more... intentional. As the extractor progresses, it spawns progressively tougher versions of the base mob that must be fought off and killed. They spawn at regular intervals and must be killed in range (16 block radius, perhaps) for the extractor to progress. If they get away, that's ok, but there's no progress for that mob and the next one comes out harder regardless. Once you've killed X mobs, the extractor completes.

Heh, just imagine the mayhem trying to get a creeper spawner.

My idea for the battle mode was to force-spawn mobs, regardless of light level. But that's a good point about dropping mobs through holes - it would be too easy to cheese it.

Not abandoning the purification idea just yet... I still quite like the idea of trapping mobs Ghostbusters style. Actually currently favouring that...

Even without purification, that ghost busters trap just sounds like so much fun to use. Bring it home, pop it in a pressure chamber to get the initial essence out (like when they would deposit the traps in the big red reactor thing).

Lol, so much nostalgia here

So, there's a build up now with some of these mechanics in place. If you're interested, give build 67 (for 1.16.3 and 1.16.4) a go...

Doesn't have all the stuff discussed here, but I think it works fairly well....

Oh, sweet. I'm definitely going to test this out, thanks for the heads up!

Alright. First impression? Amazing freaking work man. I was shocked at how fast the mobs were coming at me with the spawner extractor. Should make for a brutal surprise for anyone doing this the first time. Feels good though, it ought to be a tough fight.

Air usage feels good. I was able to get the spawner up to about 7 upgrades before some heavier infrastructure would be required. For a pure core, that spawns at a very respectable rate. And with an incomplete core it's not so painfully long. Good enough that an automated setup could be built to fill a core. Maybe even with the two cores swapping places periodically to speed the process up.

Flying mobs appear to be problematic to catch. They do go in, but Ghasts and Phantoms appear to be able to overpower the vacuum sucking. That'll probably take a fair amount of creativity from the player to overcome, like hiding out near a trap and letting the phantoms dive bomb them. It may also be possible to give the trap a hand in terms of Ghasts by setting up some air grates to push them into the block space directly above the vacuum. I don't think you need to change anything here, Let the player find a solution to these challenges.

Same with Shulkers, since they can't seem to be dragged. Those, at least, it's possible to get them by placing a charged vacuum down right next to one.

All in all, it feels like you've got the tools to make a pretty great farm with this. It requires a good amount of effort from the player, encourages them to get creative, is not overly cheap to run, and gives more incentive to use advanced compressors. It also has a very PNC feel, which is wonderful.

Oh, I didn't see anything, but is there a way to blacklist mobs? I could see a pack dev maybe wanting to blacklist certain things, like resource bees.

Nevermind, found it in the manual. My config just didn't update when I updated, I think.

Awesome, glad it's worked out well! I was concerned getting a filled spawner was going to be a bit tedious (and tbh if players have something like Industrial Foregoing available they will probably use that, but meh...), but having played with it a bit in survival as well, it's actually quite fun, especially if you're trying to be selective about what you capture.

I had noticed that flying (and swimming) mobs don't get pulled into the trap nearly as well as ground mobs. Not exactly sure why but as you say, adds a little more challenge... I do need to test out the air grate with Ghasts/Blazes/Phantoms... (although Blazes are probably easier to get by extracting a spawner).

Anyhow, v2.6.0 has just been released for 1.16.3/1.16.4, including the new spawner stuff :)

Believe it or not, I think you're actually about the only mod with sustainable 'powered' spawner at this point in 1.16. Industrial Foregoing hasn't re-implemented theirs yet and I think the plan is to gate it much later now. Apotheosis has modified vanilla spawners but it's rather tedious to work with and lacks any real charm. So this is really going to give people something fun and new to try.

Awesome work as always!

I'm using Apotheosis modded spawners this play through with industrial foregoing as the crushers (for the xp). You can't really see it very well in the two below gifs but i'm sharing the xp with a friend via Aerial Interface and yes, i have over 1300+levels getting a level about a second when it's on. I can't wait to try out the new spawners from pneumaticcraft to see if I can break those haha.