# plane var (atom)

Source: https://ref.dm-lang.org/atom/var/plane
Added in BYOND 509.

### Default value
> `FLOAT_PLANE`

### Possible values
> \-10000 to 10000 (integers only), `FLOAT_PLANE+p`

The value of plane overrides layer, and is mainly used for non-topdown map formats like isometric. Positive values are drawn on top, and negative values are drawn below. This mostly deprecates `EFFECTS_LAYER` and `BACKGROUND_LAYER`, but they can still be useful when using `PLANE_MASTER` for effects (see [appearance_flags](https://ref.dm-lang.org/atom/var/appearance_flags.md)).

The special value `FLOAT_PLANE` can be used for images and overlays, to take on the plane of the parent atom. Whenever an icon or icon_state is used directly as an overlay, this is its plane. If there is no parent atom, the plane is 0.

You can also use `FLOAT_PLANE` as a relative value, so `FLOAT_PLANE+1` adds 1 to the parent atom's plane. This may be useful for some applications where an object is included in visual contents. The added value should still be kept in the range of -10000 to 10000, or preferably much smaller.

### See also
- [layer var (atom)](https://ref.dm-lang.org/atom/var/layer.md)
- [appearance_flags var (atom)](https://ref.dm-lang.org/atom/var/appearance_flags.md)
- [vis_contents var (atom)](https://ref.dm-lang.org/atom/var/vis_contents.md)
- [map_format var (world)](https://ref.dm-lang.org/world/var/map_format.md)
- [Understanding the renderer](https://ref.dm-lang.org/notes/renderer.md)