[1.12] Custom Vine World Gen

I want to generate a special vine for my mod in world like how vines generate in vanilla swamps/jungles. Here's the code:

private void generateMoss(World world, Random rand, int chunkX, int chunkZ, Predicate<Biome> predicate) {
		BlockPos position = new BlockPos(chunkX * 16 + 8, 64, chunkZ * 16 + 8);
		Biome biome = world.getBiome(position);
		if (!predicate.test(biome)) return;
		for (; position.getY() < 128; position = position.up()) {
			if (world.isAirBlock(position) && world.isAirBlock(position.down(1))) {
				for (EnumFacing enumfacing : EnumFacing.Plane.HORIZONTAL.facings()) {
					if (ModObjects.spanish_moss.canPlaceBlockOnSide(world, position, enumfacing)) {
						IBlockState iblockstate = ModObjects.spanish_moss.getDefaultState().withProperty(BlockVine.SOUTH, enumfacing == EnumFacing.NORTH).withProperty(BlockVine.WEST, enumfacing == EnumFacing.EAST).withProperty(BlockVine.NORTH, enumfacing == EnumFacing.SOUTH).withProperty(BlockVine.EAST, enumfacing == EnumFacing.WEST);
						world.setBlockState(position, iblockstate, 2);
						break;
					}
				}
			}
			else {
				position = position.add(rand.nextInt(4) - rand.nextInt(4), 0, rand.nextInt(4) - rand.nextInt(4));
			}
		}
	}

However, this just generates very parse patches of one block vines instead of long draping vines from trees in swamps. The code here is basically copied from the vanilla class though. 

Thanks!