Let’s add some world generation into our mod that makes it so our tutorial block generates in the world. The first step to this is to create the class TutorialWorldGen in the package cubicoder.tutorialmod.world.gen. This class will implement IWorldGenerator. After you add the unimplemented method, create a constructor for the class and another, private method named genStandard().
package cubicoder.tutorialmod.world.gen;
import java.util.Random;
import net.minecraft.world.World;
import net.minecraft.world.chunk.IChunkProvider;
import net.minecraft.world.gen.IChunkGenerator;
import net.minecraft.world.gen.feature.WorldGenerator;
import net.minecraftforge.fml.common.IWorldGenerator;
public class TutorialWorldGen implements IWorldGenerator {
public TutorialWorldGen() {
}
@Override
public void generate(Random random, int chunkX, int chunkZ, World world, IChunkGenerator chunkGenerator, IChunkProvider chunkProvider) {
}
private void genStandard(WorldGenerator generator, World world, Random random, int chunkX, int chunkZ, int spawnTries, int minHeight, int maxHeight) {
}
}
Next, we need to add a field to hold the WorldGenMinable instance that will be used to generate the ore. We will initialize this in the constructor.
// ...
private final WorldGenMinable tutorialOverworldGen;
public TutorialWorldGen() {
tutorialOverworldGen = new WorldGenMinable(ModBlocks.FIRST_BLOCK.getDefaultState(), 15, BlockMatcher.forBlock(Blocks.STONE));
}
// ...
The first parameter in the WorldGenMinable constructor specifies the block that will be generated (technically, the blockstate). The second parameter is the average vein size, or about how many blocks will be in each vein. The third parameter specifies the block it will be replacing. Now we need to write our standard generation code in the genStandard() method.
// ...
private void genStandard(WorldGenerator generator, World world, Random random, int chunkX, int chunkZ, int spawnTries, int minHeight, int maxHeight) {
if(minHeight < 0) minHeight = 0;
if(maxHeight > 255) maxHeight = 255;
if(maxHeight < minHeight) {
int i = minHeight;
minHeight = maxHeight;
maxHeight = i;
} else if(maxHeight == minHeight) {
if(maxHeight < 255) {
maxHeight++;
} else minHeight--;
}
BlockPos chunkPosAsBlockPos = new BlockPos(chunkX << 4, 0, chunkZ << 4);
int heightDiff = maxHeight - minHeight + 1;
for (int i = 0; i < spawnTries; i++) {
generator.generate(world, random,
chunkPosAsBlockPos.add(
random.nextInt(16),
minHeight + random.nextInt(heightDiff),
random.nextInt(16)
)
);
}
}
The first part of this code simply does checks to make sure that the minHeight and maxHeight values are valid. Then, it finds the chunk position and randomly generates the ore based on the values we enter. It does this once for each spawn try.
Finally, we need to call the genStandard() method in the generate() method for our ore to generate. In order to do this, we must check the dimension we are in, so that we can make sure it only spawns in the Overworld.
@Override
public void generate(Random random, int chunkX, int chunkZ, World world, IChunkGenerator chunkGenerator, IChunkProvider chunkProvider) {
switch (world.provider.getDimensionType()) {
case NETHER:
break;
case OVERWORLD:
genStandard(genTutorial_overworld, world, random, chunkX, chunkZ, 10, 0, 200);
break;
case THE_END:
break;
}
}
Finally, we need to register our ore generator. In your main class’s init() method, call GameRegistry.registerWorldGenerator():
@EventHandler
public void init(FMLInitializationEvent event) {
// other init methods...
GameRegistry.registerWorldGenerator(new TutorialWorldGen(), 0);
}
The method takes in the ore generator class, as well as an int. The number specifies the generator’s weight, meaning that a higher number here would make the generator run later.
Then look in the world to find your ore! Note that you’ll have to travel far away or create a new world in order to find it, as this does not generate in already-generated chunks.
