Not actually a problem, i need a help to figure out how to generate common structures in forests that fits with the forest itself. So the structure is actually generated on the solid ground, not in water, not in air. Right now to do this i got this check in the function that loads my structure

flag = true;
			if(check) {
				for (int i = 0; i < 16; i++) {
					for (int j = 0; j < 16; j++) {
						if (!world.getBlockState(pos.add(i, -1, j)).getBlock().equals(Blocks.GRASS)) {
							flag = false;
							break;
						}
					}
				}
			}


			if (flag) {
//place the structure}

 

So here i'm saying that if an area of 16x16 blocks in the forest is made of grass than spawn the structure. But, as you might guess, in the forest is really hard to have flat plains area, and this results in the structure being pretty rare. So how can i do to make the structure generate in a proper way BUT let it not be too rare?

I'd recommend that you only check the "corners" of this area. If there are blocks inside this area, remove them. If there's a hole between & below these points, fill them in.

I've actually managed to do this, but i guess i'llchange it to check the corners

boolean flag = true;
			HashMap<BlockPos, Integer> nograss = new HashMap<BlockPos, Integer>();

			for (int i = 0; i < template.getSize().getX(); i++) {
				for (int j = 0; j < template.getSize().getZ(); j++) {
					BlockPos down = pos.add(i, -1, j);
					Block b = world.getBlockState(down).getBlock();
					if (!b.equals(Blocks.GRASS)) {
						nograss.put(down, 0);
					}
				}
			}

			if (!nograss.isEmpty()) {
				for(Entry<BlockPos, Integer> entry : nograss.entrySet()) {
					BlockPos top = world.getTopSolidOrLiquidBlock(entry.getKey());
					if(Math.abs(top.getY() - entry.getKey().getY()) > 3) {
						flag = false;
						break;
					}
					else
						entry.setValue(Math.abs(top.getY() - entry.getKey().getY()));
				}
				if(flag) {
					for(Entry<BlockPos, Integer> entry : nograss.entrySet()) {
							for(int i = 0; i < entry.getValue()+1; i++) {
								world.setBlockState(entry.getKey().down(i), Blocks.COBBLESTONE.getDefaultState());
						}
					}

				}
			}

			if (flag) { //do stuff
}

 

So what i do is: check all the blocks, if there are some blocks that don't have grass under them then add it's position to an HashMap. Then, if this HashMap is not empty check if the location of the structure (the blocks that made the base and are in the HashMap) are at most 3 blocks up from the ground. If there is at least one that is up more than 3 blocks then the structure will not generate. Else, every block that has not grass underneath is at most 3 blocks up from the ground, so place 3 blocks of cobblestone down to the ground, so it will looks like the structure has some layers of cobblestone and then the structure itself (mostly like villages sometimes generates)