Preparation
Before we get started making our corn crop, we’ll need to make a couple of changes to the base item/block infrastructure we’ve already created. Specifically what we need to change has to do with item models. Currently, BlockBase
and ItemBase
have their own registerItemModel
methods. We’re going to move this into the ItemModelProvider
interface so that blocks and items we create that don’t extend BlockBase
or ItemBase
can still use our system for registering item models.
Create a new ItemModelProvider
interface and add one method to it:
package net.shadowfacts.tutorial.item;
import net.minecraft.item.Item;
public interface ItemModelProvider {
void registerItemModel(Item item);
}
This interface functions exactly the same as the registerItemModel
methods in BlockBase
and ItemBase
.
Next, we’ll change BlockBase
to implement ItemModelProvider
. Just add the implements ItemModelProvider
after the class declaration, change the reigsterItemModel
method to accept an Item
instead of an ItemBlock
and add @Override
to the registerItemModel
method.
We’ll repeat a similar process for ItemBase
. Add implements ItemModelProvider
, change registerItemModel
to accept an Item
, and add @Override
to it.
Now that we’ve changed our BlockBase
and ItemBase
classes, we’ll need to make some changes to our ModItems
and ModBlocks
classes to ensure that ItemModelProvider#registerItemModel
is called even if the block or item isn’t a subclass of our block or item base classes.
In ModBlocks
, simply change block instanceof BlockBase
to block instanceof ItemModelProvider
and change the cast from BlockBase
to ItemModelProvider
. Do the same for the ModItems
class, replacing ItemBase
with ItemModelProvider
in the appropriate section of the code.
Due to the way we are going to implement our crop, we’ll need to make another modification to our ModBlocks
class. Before we make this modification, let me explain why it’s necessary.
Our crop is going to have 3 important parts:
- The crop block
- The seed item
- The food item
Because we have a separate seed item, the crop block won’t have an ItemBlock
to go along with it.
In our register(T block, ItemBlock itemBlock)
method, we’ll need to add a null check to itemBlock
so we don’t attempt to register itemBlock
if it’s null.
Lastly, we’ll need to make one change in our main TutorialMod
class. Due to the way Minecraft’s ItemSeed
works, our blocks need to be initialized before we can call the constructor of our seed. Simply move the ModItems.init
call in TutorialMod.preInit
to after the ModBlocks.init
call.
Crop
The crop we are going to create will be corn.
As I mentioned before, our crop will be divided into 3 main parts:
- The crop block (corn crop)
- The seed item (corn seed)
- The food item (corn)
We’re going to create these one at a time. At the intermediate stages, our code will contain errors because we are referencing things we haven’t created yet, but everything should be fine at the end.
Corn Crop
Let’s create a class called BlockCropCorn
that extends Minecraft’s BlockCrops
. The crop block won’t have an ItemBlock
so this class won’t implement ItemModelProvider
and it is why we need that null check in ModBlocks.register
.
In this class, we’ll need to override 2 methods to return our own items instead of the vanilla ones. getSeed
should return ModItems.cornSeed
and getCrop
should return ModItems.corn
.
package net.shadowfacts.tutorial.block;
import net.minecraft.block.BlockCrops;
import net.minecraft.item.Item;
import net.shadowfacts.tutorial.item.ModItems;
public class BlockCropCorn extends BlockCrops {
public BlockCropCorn() {
setUnlocalizedName("cropCorn");
setRegistryName("cropCorn");
}
@Override
protected Item getSeed() {
return ModItems.cornSeed;
}
@Override
protected Item getCrop() {
return ModItems.corn;
}
}
Minecraft will use the seed and crop we specified to determine what to drop when our crop block is broken. Let’s register our block in the ModBlocks
class:
// ...
public static BlockCropCorn cropCorn;
public static init() {
// ...
cropCorn = register(new BlockCropCorn(), null);
}
// ...
The last thing we’ll need to do is create a model. Download the textures from here and save them into src/main/resources/assets/tutorial/textures/blocks/corn/
and have there filenames the 0.png
through 7.png
.
Let’s create a blockstate for our crop. Create src/main/resources/assets/tutorial/blockstates/cropCorn.json
. We’re once again going to be using the Forge blockstates format because this is a fairly complicated blockstate.
{
"forge_marker": 1,
"defaults": {
"model": "cross"
},
"variants": {
"age": {
"0": {
"textures": {
"cross": "tutorial:blocks/corn/0"
}
},
"1": {
"textures": {
"cross": "tutorial:blocks/corn/1"
}
},
"2": {
"textures": {
"cross": "tutorial:blocks/corn/2"
}
},
"3": {
"textures": {
"cross": "tutorial:blocks/corn/3"
}
},
"4": {
"textures": {
"cross": "tutorial:blocks/corn/4"
}
},
"5": {
"textures": {
"cross": "tutorial:blocks/corn/5"
}
},
"6": {
"textures": {
"cross": "tutorial:blocks/corn/6"
}
},
"7": {
"textures": {
"cross": "tutorial:blocks/corn/7"
}
}
}
}
}
The model
specified in the defaults
section is Minecraft’s cross
model which is just the same texture rendered twice. You can see what this model looks like by looking at the various flowers in vanilla.
The age
property is the age of the crop. All the objects inside the age
object are for one value of the property. In our case, age
can have a value 0 through 7 so we’ll need separate JSON objects for each of those. For each value of age, we’ll have a different texture that is specified in the textures
object with the name cross
.
Corn Seed
Now let’s make our corn seed item. Create a new class called ItemCornSeed
that extends ItemSeeds
and implements ItemModelProvider
.
In our constructor, we’ll need to pass a couple of things to the ItemSeeds
constructor, ModBlocks.cropCorn
and Blocks.FARMLAND
. The first parameter of the ItemSeeds
constructor is the crop block and the second is the soil block. Since we implemented ItemModelProvider
, we’ll need to provide an implementation for registerItemModel
which will just use our registerItemRenderer
proxy method.
package net.shadowfacts.tutorial.item;
import net.minecraft.init.Blocks;
import net.minecraft.item.Item;
import net.minecraft.item.ItemSeeds;
import net.shadowfacts.tutorial.TutorialMod;
import net.shadowfacts.tutorial.block.ModBlocks;
public class ItemCornSeed extends ItemSeeds implements ItemModelProvider {
public ItemCornSeed() {
super(ModBlocks.cropCorn, Blocks.FARMLAND);
setUnlocalizedName("cornSeed");
setRegistryName("cornSeed");
}
@Override
public void registerItemModel(Item item) {
TutorialMod.proxy.registerItemRenderer(item, 0, "cornSeed");
}
}
Let’s register our corn seed in ModItems
.
// ...
public static ItemCornSeed cornSeed;
public static void init() {
// ...
cornSeed = register(new ItemCornSeed());
}
// ...
Lastly, we’ll create a simple JSON model for the corn seed. First you’ll want to download the texture from here and save it to src/main/resources/assets/tutorial/textures/items/cornSeed.png
. Now create a JSON file in the models/item
folder called cornSeed.json
. This model with be fairly similar to our copper ingot model, it will just have a parent of item/generated
and a layer 0 texture of tutorial:items/cornSeed
.
{
"parent": "item/generated",
"textures": {
"layer0": "tutorial:items/cornSeed"
}
}
Corn Item
For now, our corn item is going to be a simple instance of our ItemBase
class which means you won’t be able to eat it (yet!). Let’s add our corn item to our ModItems
class.
// ...
public static ItemBase corn;
public static void init() {
// ...
corn = register(new ItemBase("corn").setCreativeTab(CreativeTabs.FOOD));
}
// ...
Now let’s also make a simple model for our corn item. Download the texture from here and save it as corn.png
in the textures/items
folder. Now let’s create a corn.json
file for our model. This model will also be very simple, with a parent of item/generated
and a layer 0 texture of tutorial:items/corn
.
{
"parent": "item/generated",
"textures": {
"layer0": "tutorial:items/corn"
}
}
Localization
Now let’s quickly add localization for new items:
# ...
item.corn.name=Corn
item.cornSeed.name=Corn Seed
# ...
Finished
Now, you should be able to launch game from inside the IDE and see our corn seed in the materials creative tab, plant it, grow it with bone meal, and break it to get corn and more seeds.