Create a parallel world for the overworld and the nether.
Similar with Overworld Mirror , but it not work at 1.7.10. I play 1.7.10 with mod now so I wrote one, and add additional dimension for nether.
Use hay bale to create portal to enter parallel overworld.
Use soul sand to create portal to enter parallel nether.
Exactly same as original world terrain generation unless you change the "seed_offset" in config file.
Mod ores and structures or biomes will also generate in parallel world.
Activate portal with:
Source code:https://github.com/HuJK/MCMod_Parallel-World/
Change log:
1.0.0: Firse release
1.0.2: Fix MCreator bug (Too many zombie pigman spawn in portal block)
1.0.3: Remove some useless code generate by MCreator
1.0.6: Change config filename from "prallelWorld.cfg" to "ParallelWorld.cfg"
1.0.7: Fix MCreator bug (Portal block is ubbreakable in survival mode)
Fix the biome of Nerher is not hell
1.0.8: Fix bug for incorrect xp display
Mods made with MCreator.