Creation of Blocks

In its most simple form, the definition of a block looks like this:

{
  "type": "block:simple",
  "entries": [
    {
      "id": "my_first_block",
	  "creativeTab": "buildingBlocks"
    }
  ]
}

The id property defines the internal name of the block. It has to be unique in your mod.

If you start the game now, you should see the block in the Building Blocks creative tab and can already place it. However it still uses the missing texture and model. To fix this, you need to create a Block State file. This file tells the game what model and thus texture to use for what state of the block. The file should be located in assets/mymod/blockstates and should have the exact same name as the id of the block, in our case this is my_first_block.json. The contents of the file might look like this:

{
  "variants": {
	"normal": {"model": "mymod:my_first_block"},
	"inventory": {"model": "mymod:my_first_block"}
  }
}

The normal variant tells the game what model is being for the block in the world. In this case the model file is assets/mymod/models/block/my_first_block.json. The contents of that file might look like this:

{
    "parent": "block/cube_all",
    "textures": {
        "all": "mymod:blocks/my_first_block"
    }
}

This will make the block look like a regular cube with the texture located at assets/mymod/textures/blocks/my_first_block.png.

The inventory variant tells the game what model is being used if the block is an item in an inventory. Since this variant applies to the block's item, the file is assets/mymod/models/item/my_first_block.json. The contents of that file might look like this:

{
  "parent": "mymod:block/my_first_block",
  "display": {
    "thirdperson": {
      "rotation": [ 10, -45, 170 ],
      "translation": [ 0, 1.5, -2.75 ],
      "scale": [ 0.375, 0.375, 0.375 ]
    }
  }
}

This will make the block's item look like the block's model.

There's one last thing missing: if you hover of the block in the inventory, the displayed name is tile.my_first_block.name. This is the unlocalized name of the block. To add a localized name for it, add the following line to assets/mymod/lang/en_US.lang (create it if it doesn't exist):