I am seeing unexpected behaviour when running Forge. Spawners in dungeons are different types to the spawner in that location in a world with the same seed in Vanilla Minecraft.

 

For example, start a creative world in Vanilla with the seed 35267400.

 

/tp -238 52 389

This is a Zombie spawner.

 

Start a new world with the same seed with Forge installed, no other mods required.

/tp -238 52 389

This is now a skeleton spawner.

 

I can't see any consistency with the changes in spawners:

 

Coordinates          Vanilla  Forge

/tp -238 52 389 - zombie  skelly

/tp -143 39 110 - spider    zombie

/tp -118 29 398 - zombie  zombie

/tp -177 25 431 - zombie  skelly

/tp -481 53 517 - zombie  spider

/tp -451 50 539 - skelly    zombie

/tp -534 39 616 - skelly    zombie

/tp -524 33 548 - skelly    spider

 

The behaviour I expect is for the spawners to be the same type in both vanilla Minecraft and with Forge installed.

 

I have confirmed this behaviour on Mac with Forge 10.12.0.1023 and also Forge 10.12.0.1029.

 

Thanks for all your great work on Forge!

KeepOnDigging.

 

I'll look into it, but these types of world gen stuff are extreamly finnickey, as they are based of a Random Number Generator that has to be polled the exact correct number of times to get things to match up. So if a mod is added that polls the RNG it'll throw off everything after it.

If you're saying this is JUST forge installed, I will take a look see if I can find where the extra polls are coming from when I get back into town.

Yes, I only have Forge loaded.

 

Minecraft Forge 10.12.0.1029

3 mods loaded, 3 mods active.

 

Thanks for looking into this LexManos!

 

KeepOnDigging.

I have just confirmed that this problem still exists with Forge 10.12.1.1061.

 

I have installed just Minecraft 1.7.2, Forge and no other mods.

 

KeepOnDigging.