Render Block OBJ

In this chapter I show how you can make a block that renders a static model exported from Blender or another 3D program that supports WaveFront OBJ files. The result looks like this:

The first thing you have to do is to add this to your ClientProxy.preInit(). This makes sure the obj loader knows about your domain:

public static class ClientProxy extends CommonProxy {
    @Override
    public void preInit(FMLPreInitializationEvent e) {
        super.preInit(e);

        OBJLoader.INSTANCE.addDomain(MODID);

        ...
    }
}

Then there is the block:

public class ModelBlock extends Block {

    public ModelBlock() {
        super(Material.ROCK);
        setUnlocalizedName(ModTut.MODID + ".modelblock");
        setRegistryName("modelblock");
    }

    @SideOnly(Side.CLIENT)
    public void initModel() {
        ModelLoader.setCustomModelResourceLocation(Item.getItemFromBlock(this), 0, new ModelResourceLocation(getRegistryName(), "inventory"));
    }

    @Override
    @SideOnly(Side.CLIENT)
    public boolean shouldSideBeRendered(IBlockState blockState, IBlockAccess worldIn, BlockPos pos, EnumFacing side) {
        return false;
    }

    @Override
    public boolean isBlockNormalCube(IBlockState blockState) {
        return false;
    }

    @Override
    public boolean isOpaqueCube(IBlockState blockState) {
        return false;
    }
}

Then you also need a blockstate as usual (blockstates/modelblock.json). Here instead of using another JSON as a model we directly refer to the obj that is exported from Blender. Because Blender and Forge apparently don't agree on vertical texture coordinate (the v axis) you need to add the flip-v attribute:

blockstates/modelblock.json

{
  "forge_marker": 1,
  "defaults": {
    "custom": { "flip-v": true },
    "model": "modtut:model.obj"
  },
  "variants": {
    "normal": [{}],
    "inventory": [{}]
  }
}

The obj file you exported from Blender should go to models/block/model.obj. Note that you also need the model.mtl file which is also exported by blender, but you have to modify it so that all referenced textures now use the standard <modid>:<name> format:

models/block/model.obj

newmtl None
Ns 0
Ka 0.000000 0.000000 0.000000
Kd 0.8 0.8 0.8
Ks 0.8 0.8 0.8
d 1
illum 2
map_Kd modtut:blocks/modeltexture

Another method of adding textures is through the blockstate file, by adding texture maps. One of the benefits of this is that you can re-export your .mtl file without having to add the map_Kd line each time. Your .mtl file will have at least one newmtl [name] line. To map the texture, add #[name] to the texture map. Instead of the previous example, where you added a map_Kd line, you could just change the blockstate to the following:

{
  "forge_marker": 1,
  "defaults": {
    "custom": { "flip-v": true },
    "model": "modtut:model.obj",
    "textures": {
      "#None": "modtut:blocks/modeltexture"
    }
  },
  "variants": {
    "normal": [{}],
    "inventory": [{}]
  }
}