Non-Trivial World Altering (1)

[MephistosChan]

When ever we update then its often best to restart from scratch to ensure the proper balance of ores and other world generation spawns. You lose structures and any terraforming work every time.

How about a utility that that allows the importation of the skin of the world but regenerates the ground beneath?

This could be achieved by taking the highest and lowest point in each chunk and adding a small fudge factor (or possibly rounding to a multiple of 16 if that makes more sense with chunk loading).

Yes this is possible with MCedit but the selection area would be huge and the importation to a new world would cause large and ugly vertical breaks.

[jakj]

This would be far too fiddly. What about a mod that affects worldgen just below the surface? The fudge factor would be too imprecise, and you would get drastic breaks (like geological strata) even without that. What exactly would the algorithm use to determine ground level? Would you have to blacklist all above-ground blocks like trees and man-made structures, or would you try to whitelist simple blocks like dirt and sand as the "surface"? What about floating islands---how would the algorithm tell the difference between a floating island and regular surface with a cave beneath? What about large areas covered with marble or basalt? A world converter could not count on having the game running or having the .cfg files accessible, so you would have to configure the world converter with which versions of which mods you have installed and what block IDs they are using.

And that's just off the top of my head.

[MephistosChan]

Ah yes all true, but I did put non-trivial in the title. :)

[fabricator77]

Two major problems:

1) The usual reason for having to get a new map, is to get a new biome feature. For example the jungle biome in 1.25 or the cocoa plants in the 12w19a snapshot. Hence is the new surface you want to keep, or at least what is growing on it.

2) As jakj stated, block ID changes are another problem you'd need to deal with.

Would be easier to find the changes made to the world compared to a new version of it using the same seed. Then use that raw data somehow to locate man made structures. Note easier not easy.

How about some sort of copy paste tool which can blend edges ? That would hide the usual cliffs you end up with from copying whole chunks into a new world.

[MephistosChan]

Copy/ paste with blend would be good, add chunk select from a map and it would be perfect. There are often areas that are unused or the player would be willing to sacrifice to get new spawns.

[Shukaro]

https://github.com/hetmankp/mcmerge

Once you delete unwanted extra chunks, that will let you blend chunk boundaries together.