shadowfacts.net/site/tutorials/forge-modding-112/json-block-models.md

metadata.title = "JSON Block Models"
metadata.date = "2016-08-08 13:58:00 -0400"
metadata.series = "forge-modding-112"
metadata.seriesName = "Forge Mods for 1.12"

We're going to add a new block that has a custom JSON model (that is, one defined completely by us, not one of Mojang's).

The first thing we'll need to do is create a block class. We need to create a new class instead of just using the BlockBase class because w'll need to override a couple of methods to have the model render properly. Our BlockPedestal class will extend our BlockBase class so we can use the code we've already written for item model registration.

The two methods we'll be override are isOpaqueCube and isFullCube. In both of these methods, we'll want to return false from both of these methods in order to change some of the default Minecraft behavior.

isOpaqueCube is used to determine if this block should cull faces of the adjacent block. Since our block doesn't take up the entirety of the 1m^3 cube, we'll want to return false so the faces of adjacent blocks can be seen behind our block.

isFullCube is used to determine if light should pass through the block. Once again, we'll want to return false because our block is less than 1m^3 so we'll want light to propgate through it.

package net.shadowfacts.tutorial.block;

import net.minecraft.block.material.Material;
import net.minecraft.block.state.IBlockState;

public class BlockPedestal extends BlockBase {

	public BlockPedestal() {
		super(Material.ROCK, "pedestal");
	}
	
	@Override
	@Deprecated
	public boolean isOpaqueCube(IBlockState state) {
		return false;
	}
	
	@Override
	@Deprecated
	public boolean isFullCube(IBlockState state) {
		return false;
	}

}

Next, we'll need to register our pedestal block in our ModBlocks class.

// ...
public class ModBlocks {
	// ...
	public static BlockPedestal pedestal = new BlockPedestal();
	// ...
}

Don't forget to add a localization for the pedestal block!

# Blocks
# ...
tile.pedestal.name=Pedestal
# ...

Next we'll need to create a blockstate file at assets/tutorial/blockstates/pedestal.json that tells Forge which model to use for the normal variant and the inventory variant.

Note: See Basic Forge Blockstates for more information about the Forge blockstate format.

{
	"forge_marker": 1,
	"variants": {
		"normal": {
			"model": "tutorial:pedestal"
		},
		"inventory": {
			"model": "tutorial:pedestal",
			"transform": "forge:default-block"
		}
	}
}

Our blockstate file does a couple of things.

1. It instructs Forge to use the model at assets/tutorial/models/block/pedestal.json for both the normal and inventory variants.
2. It uses the forge:default-block transformation for the inventory variant. This makes the block appear at the proper angle in the inventory and in the hand.

Now we need to create the Pedestal model itself. The model will be located at assets/tutorial/models/block/pedestal.json.

{
	"textures": {
		"pedestal": "blocks/stonebrick",
		"particle": "blocks/stonebrick"
	},
	"elements": [
		{
			"from": [3, 0, 3],
			"to": [13, 11, 13],
			"faces": {
				"down": {
					"uv": [0, 0, 10, 10],
					"texture": "#pedestal",
					"cullface": "down"
				},
				"north": {
					"uv": [0, 0, 10, 11],
					"texture": "#pedestal"
				},
				"south": {
					"uv": [0, 0, 10, 11],
					"texture": "#pedestal"
				},
				"west": {
					"uv": [0, 0, 10, 11],
					"texture": "#pedestal"
				},
				"east": {
					"uv": [0, 0, 10, 11],
					"texture": "#pedestal"
				}
			}
		},
		{
			"from": [2, 11, 2],
			"to": [14, 12, 14],
			"faces": {
				"down": {
					"uv": [0, 0, 12, 12],
					"texture": "#pedestal"
				},
				"north": {
					"uv": [0, 0, 12, 1],
					"texture": "#pedestal"
				},
				"south": {
					"uv": [0, 0, 12, 1],
					"texture": "#pedestal"
				},
				"west": {
					"uv": [0, 0, 12, 1],
					"texture": "#pedestal"
				},
				"east": {
					"uv": [0, 0, 12, 1],
					"texture": "#pedestal"
				}
			}
		},
		{
			"from": [1, 12, 1],
			"to": [15, 13, 15],
			"faces": {
				"down": {
					"uv": [0, 0, 14, 14],
					"texture": "#pedestal"
				},
				"up": {
					"uv": [0, 0, 14, 14],
					"texture": "#pedestal"
				},
				"north": {
					"uv": [0, 0, 14, 1],
					"texture": "#pedestal"
				},
				"south": {
					"uv": [0, 0, 14, 1],
					"texture": "#pedestal"
				},
				"west": {
					"uv": [0, 0, 14, 1],
					"texture": "#pedestal"
				},
				"east": {
					"uv": [0, 0, 14, 1],
					"texture": "#pedestal"
				}
			}
		}
	]
}

The model has two primary parts, the textures and the elements.

The textures section contains a map of texture name to the location of the texture itself. We define the pedestal texture as blocks/stonebrick and then reference it using #pedestal in the face texture attribute. (The particle texture is used by Minecraft to generate the block breaking particle.)

The elements section is an array of all the cuboid elements that the model is composed of.

Each element has 3 properties:

1. from: This is the bottom/left/backmost point of the element.
2. to: This is the top/right/frontmost point of the elemnt. With the from property, this is used to determine the size of the element.
3. faces: This is an object containg a map of directions to faces. All the faces are optional.

Each face has several properties:

1. texture: This is the texture to use for the face. This can be a reference to a predefined texture (e.g. #pedestal) or a direct reference (e.g. blocks/stonebrick).
2. uv: This is an array of 4 integer elements representing the minimum U, mimumin V, maximum U, and maximum V (in that order). The U coordinates are the top and bottom Y coordinates of the texture defining the vertical section of the texture to use. The V coordinates are the left and right X coordinates of the texture defining the horizontal section of the texture to use.
3. cullface: This is optional. If specified, this face will be culled if there is a solid block against the specified face of the block.