Switching to new modpack but keeping my stuff from my old world?

[Ieldra]

I've added too many mods with new worldgen. I'm fed up with going "elsewhere" to mine and want to restart with FTB Monster (+AM2) rather than DW20.

But I don't want to lose all my stuff since I dislike the early game. I've tried this: dump stuff in my ME network, put the storage modules and some strategic resources in a few resonant strongboxes, keep those in my inventory and copy the player and level.dat files over. That does work nicely, barring a new non-critical ID conflicts, but apparently some terrain data is moved over as well, resulting in odd biome and terrain changes along straight lines after loading the new world with the old level.dat. This can be avoided by using the same seed but that same seed does not generate the same world in Monster as it does in DW20, even using the exact same settings. Which would not be a problem if I liked that world, but I don't. It is totally boring.

Ideally, I would want my old world restarted with a different modpack. Since that does not appear to be possible, I want to have some of my old stuff as described above in a world newly-created from some non-random seed, without those terrain problems. I would also like to keep my Thaumcraft and Ars Magica research.

I'm sure that's possible somehow. I just haven't found out how. Someone has recommended creating a Mystcraft Age, copying the complete old world over to there and take from there whatever I need. That would probably not let me keep my research though...

(Something occurred to me: is it possible to recreate a world but keep player data by setting a new seed with NBT Explorer, deleting all terrain data and load the world)?

 

[belgabor]

Should be possible to kill the remnants of your old world with MCEdit, but I don't know it well enough to say for sure.

 

[Ieldra]

All right I think I solved this problem myself. 90% of it, anyway:

(1) Create a new world in Monster
(2) Copy the level.dat of the old world over. If both are from FTB modpacks for the same Minecraft version the number of ID conflicts should be minimal - or irrelevant, if they're about mods not in the new pack.
(3) Use NBT Explorer to set a new seed for the new world (Open the new world's level.dat for that). Save the edited level.dat and delete all dimension and region data from the world folder. Also delete the relevant Mapwriter data.
(4) Load the world. Terrain will be created and should be OK, and your Thaumcraft research is carried over by copying the level.dat of the old world.
(5) Repeat 3 and 4 until you like the world.

I haven't checked Ars Magica research yet but the unlocked entries of the Arcane compendium are kept in a text file you can edit, and if you lost knowledge of spell components you can re-create that by cheating some Infinity Orbs in. Now if I could find a way to recreate my old world exactly, terrain-wise, my day would be perfect.

 

[GreenZombie]

How about:
1. make sure both packs have mystcraft.
2. Create a mystcraft age, and move some critical infrustructure there.
3. Create a completely new world with the new pack.
4. Copy over the MYST_DIM1 folder and the 'agedata.dat' file from the .\data folder of the old world.
5. /tpx as an OP can port you to the age to access your stuff.

--
But really, level.dat doesn't carry any world data. What you need to do is copy level.dat over to the new game AND DELETE THE REGION folder, to regen the initial chunks that were generated with the overwritten level.dat's seed.

 

[Ieldra]

How about:
But really, level.dat doesn't carry any world data. What you need to do is copy level.dat over to the new game AND DELETE THE REGION folder, to regen the initial chunks that were generated with the overwritten level.dat's seed.

Yep, doing that. I wonder if there's a way to recreate the geography of my old world. I'm ok with the new one - just wondering. Because the same seed doesn't create the same world, even though the world creation parameters are the same.

 

[GreenZombie]

Yep, doing that. I wonder if there's a way to recreate the geography of my old world. I'm ok with the new one - just wondering. Because the same seed doesn't create the same world, even though the world creation parameters are the same.

Well, between your old and new pack the mods that have added biomes have changed.

In the best case, you are using the same world generator, and the coarse geography should be the same: i.e. all the rivers and ocean biomes will be in the same place, and the land biomes will have the same general shapes and borders - the actual biome assignments will be different however, and that is unavoidable, unless you can ensure that both mod packs have the exact same number of biomes registered.

 

[Ieldra]

All right, that worked well. I have a shiny new world, with most of my old base dismantled, packed up and transferred, and with my Thaumcraft and AM2 research including created spells apparently intact.

LOL, this was some moving day:

My old workshop before dismantling:

My old workshop before moving out (I magically switched the quarried stone back into cobble so I would have more of my preferred building material in my new world):

An finally, my new home. Looks a bit drab yet, but there's a nice deep river which will satisfy my power needs until I need to run the Extractor again:

The biggest downside is that I need to capture new aura nodes. Also my flux wrench was replaced by some block update detector and I had to cheat it back in. All in all, it appears not too bad. There are some Mystcraft related conflict error messages in the log of this kind:

2014-06-19 22:46:48 [Information] [STDOUT] CONFLICT @ 1028 item slot already occupied by net.minecraft.item.ItemBlock@146c981f while adding net.minecraft.item.ItemBlock@657725b2
2014-06-19 22:46:48 [Information] [fml.ItemTracker] The mod Mystcraft is overwriting existing item at 1284 (com.xcompwiz.mystcraft.block.BlockInkMixer from Mystcraft) with net.minecraft.item.ItemBlock

...but I would be very surprised if Mystcraft had problems.

 

[YX33A]

The MystCraft issue is mostly a non-issue. Mods occasionally overwrite their own items. AM2 does it as well. AM2 does it because it's a hacky solution to a stupid issue but a better solution Mithion has yet to locate.

That said, why one wouldn't use AE Dimensional Storage for such a task is well and truly beyond me. It's a simple, yet elegant solution for moving your base. Just need a 256x256 spatial storage cell or dozen, and no part of your base is left behind. May want to sort them, and freaking name them if possible, because putting it all back together again can be a right bitch if it's a big base.

 

[Ieldra]

The MystCraft issue is mostly a non-issue. Mods occasionally overwrite their own items. AM2 does it as well. AM2 does it because it's a hacky solution to a stupid issue but a better solution Mithion has yet to locate.

That said, why one wouldn't use AE Dimensional Storage for such a task is well and truly beyond me. It's a simple, yet elegant solution for moving your base. Just need a 256x256 spatial storage cell or dozen, and no part of your base is left behind. May want to sort them, and freaking name them if possible, because putting it all back together again can be a right bitch if it's a big base.

I was in the process of building a new base anyway, because the old one showed all signs of organic growth and its logistics were inefficient. I didn't want it as it was. Also, the power cost of AE spatial storage was beyond me at this point.

I thought of using it to store my aura nodes, but....too late. I had already dismantled my power generation at that time.