Fabric Wiki

Making blocks directional (facing into certain directions) is also done using block states. This example describes a vertical version of the andesite slab.

public class PolishedAndesiteSideBlock extends HorizontalFacingBlock {

	public PolishedAndesiteSideBlock(Settings settings) {
		super(settings);
		setDefaultState(this.stateManager.getDefaultState().with(Properties.HORIZONTAL_FACING, Direction.NORTH));
	}

	@Override
	protected void appendProperties(StateManager.Builder<Block, BlockState> stateManager) {
		stateManager.add(Properties.HORIZONTAL_FACING);
	}

	@Override
	public VoxelShape getOutlineShape(BlockState state, BlockView view, BlockPos pos, EntityContext ctx) {
		Direction dir = state.get(FACING);
		switch(dir) {
			case NORTH:
				return VoxelShapes.cuboid(0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.5f);
			case SOUTH:
				return VoxelShapes.cuboid(0.0f, 0.0f, 0.5f, 1.0f, 1.0f, 1.0f);
			case EAST:
				return VoxelShapes.cuboid(0.5f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f);
			case WEST:
				return VoxelShapes.cuboid(0.0f, 0.0f, 0.0f, 0.5f, 1.0f, 1.0f);
			default:
				return VoxelShapes.fullCube();
		}
	}

	public BlockState getPlacementState(ItemPlacementContext ctx) {
		return (BlockState)this.getDefaultState().with(FACING, ctx.getPlayerFacing());
	}

}

polished_andesite_side_block.json

{
  "variants": {
    "facing=north": { "model": "bitmod:block/polished_andesite_side_block" },
    "facing=east":  { "model": "bitmod:block/polished_andesite_side_block", "y":  90},
    "facing=south": { "model": "bitmod:block/polished_andesite_side_block", "y": 180 },
    "facing=west":  { "model": "bitmod:block/polished_andesite_side_block", "y": 270 }
  }
}

side.json

{   "parent": "block/block",
    "textures": {
        "particle": "#side"
    },
    "elements": [
        {   "from": [ 0, 0, 0 ],
            "to": [  16, 16, 8 ],
            "faces": {
                "down":  { "uv": [ 0, 8, 16, 16 ], "texture": "#bottom", "cullface": "down" },
                "up":    { "uv": [ 0, 8, 16, 16 ], "texture": "#top",    "cullface": "up" },
                "north": { "uv": [ 0, 0, 16, 16 ], "texture": "#side",   "cullface": "north" },
                "south": { "uv": [ 0, 0, 16, 16 ], "texture": "#side"  },
                "west":  { "texture": "#side",   "cullface": "west" },
                "east":  { "texture": "#side",   "cullface": "east" }
            }
        }
    ]
}

polished_andesite_side_block.json

{
    "parent": "bitmod:block/side",
    "textures": {
        "bottom": "block/polished_andesite",
        "top": "block/polished_andesite",
        "side": "block/polished_andesite"
    }
}