# EFFECTS_LAYER

Source: https://ref.dm-lang.org/notes/EFFECTS_LAYER

This is mostly no longer needed. A negative value for plane is the preferred way to do show objects in the background. It can still be used however when you want to rearrange objects in the same plane when using [PLANE_MASTER](https://ref.dm-lang.org/atom/var/appearance_flags.md) for visual effects.

`EFFECTS_LAYER` is a special high value that can be added to the regular layer of any atom.

The purpose of this value is to make an atom appear above any regular atoms. For instance, in an isometric map if you want to display a character's name below them, it does not make much sense to have nearer objects cover up that name, so you can tell the name overlay to use `EFFECTS_LAYER + MOB_LAYER` and it will show up on top of all the normal icons on the map. This has been somewhat obviated by `plane` but may still be useful in some cases.

When using this special layer, it should be added to the layer an atom normally uses. For instance an obj should have a layer of `EFFECTS_LAYER + OBJ_LAYER`.

This can be mixed with `TOPDOWN_LAYER`, in non-topdown map formats. Anything in `TOPDOWN_LAYER` will display on top of `EFFECTS_LAYER`, and `TOPDOWN_LAYER + EFFECTS_LAYER` will be above both.

This can also be mixed with `BACKGROUND_LAYER`, which takes priority over everything else.

Images or overlays with `FLOAT_LAYER` can be left alone. They will automatically have the same layer as whatever atom they are attached to.

### See also
- [layer var (atom)](https://ref.dm-lang.org/atom/var/layer.md)
- [plane var (atom)](https://ref.dm-lang.org/atom/var/plane.md)
- [map_format var (world)](https://ref.dm-lang.org/world/var/map_format.md)
- [BACKGROUND_LAYER](https://ref.dm-lang.org/notes/BACKGROUND_LAYER.md)
- [TOPDOWN_LAYER](https://ref.dm-lang.org/notes/TOPDOWN_LAYER.md)
- [stddef.dm file](https://ref.dm-lang.org/appendix/stddefdotdm.md)
- [Understanding the renderer](https://ref.dm-lang.org/notes/renderer.md)