What is an overlay?
Each of a creatures body parts is capable of having a new sprite drawn over the top of it (or even replacing it), these are called overlays. Each body part can have up to 4 overlays. Each overlay is drawn over the last so that you can still see parts of the lower layers through it.
Overlay naming convention
The overlays reside in the "creatures 3/overlay data" folder. They are named using a similar method to creature body sprites and attachment files - the only difference is that the overlay file is prefixed with "over_". For example, "a00a.c16" refers to a file associated with the head of a male Bruin Norn at the baby stage of life (see the Creature Body section for details), so to make an overlay for this it would be named "over_a00a.c16".
File contents
Each file can contain a set of overlay images - there must be 16 images for each item. These 16 images correspond to the 4 poses facing left, the 4 poses facing right, the 4 poses faces forwards and the 4 poses facing backwards. Each item should have these 16 entries - even if they are blank - and then any new items can be added to the end of this file. For example, you can create one overlay file that contains all the hats a creature may wear - the first 16 might be a cowboy hat, the second 16 could correspond to a police helmet, the 3rd 16 could correspond to a space helmet etc.
Relevant CAOS commands
The WEAR macro has the following syntax:
WEAR <body part ID> <set_number> <layer>
Where <body part ID> is:
| Body part | ID |
| Head | 0 |
| Body | 1 |
| Left Thigh | 2 |
| Left Shin | 3 |
| Left Foot | 4 |
| Right Thigh | 5 |
| Right Shin | 6 |
| Right Foot | 7 |
| Left Humerus | 8 |
| Left Radius | 9 |
| Right Humerus | 10 |
| Right Radius | 11 |
| Tail Root | 12 |
| Tail Tip | 13 |
<set number> is an index into the sprite file (because there are 16 images per set), so this number relates to which 'set' of images you want to use. In the word example given above to get the first set of hats you would use a set number of 0.
Using a set number of -1 removes that specified layer of clothing.
<layer> is a number between 0 and 3 or -1. Layer 0 will totally replace the body part with the overlay whereas layers 1-3 will be displayed on top of the existing body part. Layer -1 will remove all clothing layers from the creature.
Other CAOS commands
BODY <set number> <layer>
This sets every body part to the relevant set number and layer
NUDE
Removes all clothing.