[1.12] Cascading worldgen lag

[JimiIT92]

In my WorldGenMinable i've added some code to generate some underwater plants. The code i'm using is the same code i used in 1.10 and always worked. But in 1.12 i'm giving this odd error when creating a new world or loading new chunks

MineWorld loaded a new chunk (-115, -93  Dimension: 0) during chunk population, causing cascading worldgen lag. Please report this to the mod's issue tracker. This log can be disabled in the Forge config.

This is the class i'm using to place the blocks underwater

 
	package com.mw.world.gen.feature;
	import java.util.Random;
	import com.mw.blocks.BlockUnderwaterPlant;
	import net.minecraft.block.Block;
import net.minecraft.block.state.IBlockState;
import net.minecraft.init.Biomes;
import net.minecraft.init.Blocks;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;
import net.minecraft.world.gen.feature.WorldGenerator;
	public class WorldGenUnderwaterPlants extends WorldGenerator{
	    private IBlockState state;
    
    public WorldGenUnderwaterPlants(IBlockState stateIn) {
        this.state = stateIn;
    }
    
    @Override
    public boolean generate(World worldIn, Random rand, BlockPos pos) {
        if(worldIn.getBlockState(pos).getBlock() != Blocks.WATER || 
                worldIn.getBlockState(pos.up()).getBlock() != Blocks.WATER)
            return false;
        if(worldIn.getBiome(pos) == Biomes.OCEAN ||
                worldIn.getBiome(pos) == Biomes.DEEP_OCEAN) {
            if((worldIn.getBlockState(pos.down()).getBlock() != Blocks.SAND ||
                    worldIn.getBlockState(pos.down()).getBlock() != Blocks.DIRT ||
                    worldIn.getBlockState(pos.down()).getBlock() != Blocks.GRAVEL) 
                    && this.state.getBlock() instanceof BlockUnderwaterPlant)
                if(!worldIn.isAirBlock(pos))
                worldIn.setBlockState(pos.down(), Blocks.SAND.getDefaultState());
            worldIn.setBlockState(pos, state);
            return true;
        }
        return false;
    }
}

[LexManos]

It works yes, but it causes other chunks to be loaded. 

You can see here for more information here

But basically in this case, you problem is your setBlock doesn't have any flags passed in so it notifies the neighbors of the change, which if you're on a chunk border loads the other chunk.

[JimiIT92]

I've tried adding a flag to the setBlockState, by doing this

worldIn.setBlockState(pos.down(), Blocks.SAND.getDefaultState(), 2);

But that doesn't fixed this

[quadraxis]

For worldgen, you should probably pass the flag 18 (16 | 2). Otherwise the game will trigger updates for observers, which will also load chunks.

 

In this case, vanilla isn't the best example to follow, as Mojang didn't update the flags they used for worldgen when that new flag was added.

[JimiIT92]

No matter if i set the flag to 2, 16 or 16|2, it still spams that error The thing i don't unserstand is why it happens only with this, and not for example with custom flower generation

[CosmicDan]

On 20/09/2017 at 6:58 AM, JimiIT92 said:

No matter if i set the flag to 2, 16 or 16|2, it still spams that error The thing i don't unserstand is why it happens only with this, and not for example with custom flower generation

What about 19?

 

Seems quite a few mods have this problem and nobody knows how to fix it. Maybe you should add an option to dump a stacktrace with these warnings @LexManos because it is a bit of a problem.

[LexManos]

No, you're in the dev environment, Just set a breakpoint at the info line and see the stack yourself...

[JimiIT92]

Tried with 16|3 (19), still had that error I tried with every flag and i always got this message, but only for underwater plants (i have a custom flowers generator and that never gave me an error)