[Solved]redoing world generation with custom ores

[aw_wolfe]

1.11.2

 

I lack in understanding how minecraft generates the world block information. I had been assuming that everything is generated on the fly when the system asks for a chunk of blocks and then minecraft data only stores things that the players have changed. So it 'overlays' the changes onto the procedural generation.--This may not be correct.

My issue is that I created some ores and set them to generate (using one of many examples) and they all did (or so I thought).  One ore was meant to be very rare, much rarer than diamonds. I am using this modding to teach my kids java, so for fun, I sent them looking for the rare or ('mithril'). They couldn't find it. So I created a custom command "/find [object] [radius]" that searches a given radius of blocks for a specific object(block).  Anyway, my rare ore wasn't generating at all. Testing it out, the minimum parameters I found actually generated any ore were (size=3, chances=1),so calling WorldGenMinable(ore, [size<3]) never produced any ore, ever.

 

genSurface(...){
	....
	generateOre(ModBlocks.oreMithril.getDefaultState(),world,random,chunkX*16,chunkZ*16,2,30,3,1);//min to spawn any
}

private void generateOre(IBlockState ore, World world, Random random, int x, int z, int minY, int maxY, int size, int chances) {
		int deltaY = maxY - minY;
	
		for (int i = 0; i < chances; i++) {
			BlockPos pos = new BlockPos(x + random.nextInt(16), minY + random.nextInt(deltaY), z + random.nextInt(16));
	
			WorldGenMinable generator = new WorldGenMinable(ore, size);
			generator.generate(world, random, pos);
		}
	}

I'm sure there is some reason in the WorldGenMinable code why...but, while doing all this, my kids were building their little world. After fixing the mithril ore, I tested in newly created world and it worked, generating at a rate of about 1/10 of diamond ore. Updating the mod in the game my kids were enjoying, and reloading the game. I once again checked with my /find command and the mithril was still not being generated. This I'm not sure why. my find searches over 8,000,000 blocks. I did not think that the blocks were created and stored at game creation, only a table or registered blocks and a procedural generation was done...if so, the new updated mod should have created some mithril.

 

Obviously, I don't know what is going on. If anyone can state how the minecraft world gen, data, overlay works, I'd appreciate it.  Also, if there is anything I can do to update a previous world with new worldgen (no new ores, just changing the chances of creating), I'd more than appreciate it (kids too).

 

Thanks,

Tony

Edited March 31, 2017 by aw_wolfe
solved

[Draco18s]

  On 3/31/2017 at 1:37 AM, aw_wolfe said:

So it 'overlays' the changes onto the procedural generation.--This may not be correct.

Expand  

It is not.

When a chunk is generated fresh, it gets saved, regardless of if anything changed or not.

[TheMasterGabriel]

  On 3/31/2017 at 1:37 AM, aw_wolfe said:

minecraft data only stores things that the players have changed.

Expand  

 

 

 

 

 

 

Minecraft has no concept of what you've changed unless you explicitly code it to. When a chunk generates, it looks at what biome it is supposed to be, generates the height map (placing the biome-specific surface blocks as well), and then decorates it with ores, trees, structures, etc. Then that's it; it will not be generated/populated again. Once a chunk has been generated, it stays in that state forever (unless a mod regens the chunk manually, like Rejuvenation Missiles from ICBM). In your case, if a chunk generates before your ore is set to spawn, it will not spawn in that chunk. Any new world decorating you do (like fixing the spawn rate of your ore ) will only occur in freshly generated chunks.

 

Edit:

  On 3/31/2017 at 1:37 AM, aw_wolfe said:

8,000,000

Expand  

 

 The fact that you were iterating over such a huge number of blocks also probably led you to think nothing was happening, when in fact it either crashed internally, was just taking a ridiculously long time, both, or something in between.

Edited March 31, 2017 by TheMasterGabriel

[aw_wolfe]

Thanks.

 

I do get a return on /find command, even for the large searches...even if to say '0 found'. I figured the large search area would be well outside anything generated when my player is first created. I am testing against searching for diamonds and can search a radius of 300 in about 6 seconds.

 

I loaded new ore mod in a new world (generated with old ore mod and no mithril) and it did not find any. Then spend a few minutes flying off in one direction and re-searched,  and found some. So Draco is correct.  I did not expect minecraft to create that many chunks at start of game.

 

I think I'll write a custom command to turn some stone into mithril and use it once to 'patch' a world and then rely on the worldgen to take care of new areas.

Thanks.