How can I reload map chunks to their original state in SMP?

One of the frustrating things about working with server mods is that if a mod updates with a new feature that requires you to find something that spawns, you won't be able to find it in any of the chunks that have been saved in the world. If you are on an SMP server that gets a lot of use, you really need to travel far to find these things (it could be a new type or ore or maybe a new type of tree that spawns maybe) Most chunks are still pristine and untouched but have been added to the world file because someone came by that chunk at one point.

It would be great if I could have chunks 'refresh' or 'rollback' to their original state instead of starting fresh on a new world.

Is there any way to do something like this?

Solution 1:

Deleting the region file should force the game to regenerate the chunks when they are entered.

Region files are located in a subfolder of the world directory called "region", and have names in the form r.x.z.mcr, where x and z are the region's coordinates. The coordinates for the region a chunk belongs to can be found by taking the floor of the chunk coordinates divided by 32.

You can also use World Edit's //regen command to regenerate specific areas of the map.

Solution 2:

1. Get WorldEdit,
2. Select the area with //pos1 and //pos2
3. //expand vert the selected area vertically (bedrock to sky)
4. Use the command //regen and that area will be reset back to normal as if no one touched it.