When creating a new layer, you must specify a background tile. This tile will fill the new layer. Keep in mind that this doesn't necessarily form the background because placing any tile on the layer will remove the existing tile at that position and replace it with a new tile. For a true background, you should use a separate layer behind this layer. When editing an existing layer, specifying a background tile will replace all tiles on the layer with the value specified here. A value of "-1" for the background tile will leave the layer's tiles as they are (only an option when updating an existing layer). If you want to see what tiles are available, use the wizard by clicking on the "Wizard..." button.

Version 2.3.0 introduced support for real-time lighting effects in desktop-based projects (as opposed to HTML 5 projects). But sometimes not all layers need to be affected by lighting effects. Lighting can be disabled for a layer to simplify the layer's design, as an optimization or simply for aesthetic reasons. Enabling lighting alone does not introduce all the fancy effects right away. Light sources must be added and configured. For more details on using light sources, see the lighting tutorial.

Each layer must be associated with exactly one Tileset. The tileset maps tile values on the layer (which are simply numbers) to images displayed at the tiles' respective locations. Many details of how tiles are displayed on the layer are defined in the tileset. See the Tileset Editor for details about the effects of various tileset parameters. For a visual tileset selector, use the wizard by clicking on the "Wizard..." button.

Each tile on the layer is represented as a number. But the number is limited. If you don't have too many tiles in your tileset, you can store each tile in a single byte (which is a number between 0 and 255, inclusive). This results in a relatively small amount of memory required to store the layer's tiles. However, if you have more than 256 tiles in the tileset, you will need to use more than one byte per tile to store the number associated with each tile. Using 2 bytes per tile doubles the amount of space used to store the tiles of your layer, but allows you to put up to 32,768 different tiles on the layer. (A 2-byte integer can contain 65536 different values, but half of them are reserved for negative numbers, and 32,768 seems like a reasonably high enough number that the other half of the range is not important.) It's hard to imagine a realistic use for using 4-bytes per tile, but it is provided for completeness and allows you to distinguish over 2 billion types of tiles. Using the wizard will automatically suggest a reasonable value for this based on the number of tiles in the tileset.

The sprites contained within a layer can draw behind the tiles, interleaved with the tiles, or in front of the tiles on the layer. The layer's priority value (combined with the sprites' priority values) determines where the layer's tiles draw in relation to the sprites. A priority of 0 will draw before (behind) a priority of 1, so if you want your sprites to remain in front of the layer's tiles when there is overlap, you can set the priority of the layer to be less than that of the sprites. If the priority of the layer is equal to the priority of a sprite, the sprite will be drawn in front of tiles above it and behind tiles below it. More specifically, the sprite will draw behind a tile if the tile's origin is below that of the sprite, otherwise it will draw in front of it. The position of the origin in relation to the graphic can be observed in the frame editor tab of the Frameset Editor. Since the default priority of sprites is 1, 0 is a good priority for the layer if you generally want your sprites to be drawn in front. Interleaving sprites is primarily designed for an isometric view.

If the scroll rate of a layer is set to a value other than 0, it will automatically scroll when the map scrolls (for example, when "ScrollSpriteIntoView" occurs). By setting different layers to have different scroll rates, you can achieve a parallax scrolling 3-D-looking effect. For parallax scrolling, layers farther in the background generally have a scroll rate less than 1 but greater than 0, and layers appearing in the foreground (in front of the layer where play is taking place) would have a scroll rate greater than 1. The horizontal scroll rate can be specified independently of the vertical scroll rate. It's reasonable to have a background layer that scrolls at a rate of 0.5 horizontally and 0 vertically (no vertical scrolling).

If both scroll rates are set to 0, you can still move the layer manually. For example, it's conceivable that you could use a layer like a very large sprite by setting the scroll rate to 0 and moving it manually.

The name uniquely identifies the layer within its parent map. It only needs to be unique among the layers in the same map. The name must begin with a letter and contain only letters, digits and spaces.

Layers don't all have to be aligned to the top left corner of the map. By setting these properties, you can position a small layer somewhere in the middle of the map that only draws when that part of the map scrolls into view. The wizard provides a visual way to position a layer in the map. Keep in mind, however, that sprites in a layer cannot normally interact with tiles or sprites in another layer (although rules could conceivably be written to do so), so this should be used only for visual effects.

OffsetX represents the number of pixels between the left edge of the map and the left edge of the layer. OffsetY represents the number of pixels between the top of the map and the top of the layer. If the offset is set on a layer whose scroll rate is not 1, be aware that this offset represents the number of pixels between the edge of the map and the edge of the layer when the map is scrolled to position 0,0. Once the map begins scrolling, this offset will change according to the layer's scroll rate. For example, a layer whose OffsetX is set to 10 will be 10 pixels from the left edge of the map to start with. But if ScrollRateX is set to 2 and the map scrolls 5 pixels to the right, then the left edge of the layer will be aligned with the left edge of the map (no offset).

This determines how many rows and columns of tiles are stored in the layer. The total number of tiles, of course, ends up being the width multiplied by the height. To determine the number of bytes required to store a layer's tiles, multiply the width by the height, and then by the number of bytes per tile (specified above). This doesn't necessarily specify how big the layer's display is, but by default (when VirtualSize is set to zeros) this does also determine how big the layer appears on the map. See VirtualSize below for more details about a layer's display size and how it interacts with SizeInTiles.

The display size of a layer can be set independently of the size of its data. VirtualSize defines how many rows and columns of tiles (yes, it's defined in tiles, not pixels) the layer will "pretend" to have. That means that the number of tiles in the layer (SizeInTiles) doesn't necessarily define how far the layer can scroll or where it ends. However, if VirtualSize is set to 0, SizeInTiles does then define the display size as well as the data size. When VirtualSize is larger than SizeInTiles, the data "wraps" so that the data from the left edge of the layer appears at the right when scrolling past the right edge of the SizeInTiles width.

This can be useful for implementing a repetetive background layer. The SizeInTiles cold be very small like 5x5. Then you can wrap that to fill the whole background by setting the VirtualSize to match that of the other layers in the map. It could also be used to achieve a wrapping effect by allowing the player to walk off one edge (seeing the right edge of the map) and "secretly" teleport back to the left edge after the edge is no longer visible on the screen. Keep in mind however, that this only affects the layer's tiles. If you put a sprite someplace on the layer, then scroll far off the edge to find an identical area based on the same tiles, the sprite will not appear there.

This can be seen as either a limitation or a feature. The player can interact with the tiles as if they are in a wrapped world, and removing a tile from one "copy" affects all "copies" of the displayed layer tiles, but the sprites and plans on the layer will only be in one of the copies unless you do extra work to make sure they are always on the "copy" that's currently scrolled into view. That's the limitation. However, this can also be used as a feature in some cases. You could create a relatively simple level that appears to wrap infinitely (specify a very large virtual size). This gives you a lot of "level" for a relatively small amount of work and a small amount of data (storage space). Then you can hide a sprite here or a plan there to introduce unique features into various "copies" of the layer without having to duplicate all the tiles in the layer.

This determines where the layer appears within the sequence of the layers in the map. The lowest ZIndex is drawn first, farthest in the background. The highest is drawn last in the foreground. The wizard has a helpful interface to sort the layers into the desired arrangement and adjust the ZIndex properties of multiple layers accordingly.