When rigging and animating game sprites, you need to keep in mind the size of the exported sprite sheets as well as the resources required to play out their animations. If you are working on a console or PC game, you have a lot of leeway for both, as they generally have a lot of disk space and good video cards. If you are working on a mobile game, you might need to take steps to ensure your animation and sprite sheets are light, as mobile devices have slower rendering hardware, more limited disk space and some users may want to download your game over a mobile data network with costly data charges.
- If you are exporting a rigged sprite sheet, it is recommended to use geometrical transformations to animate the body parts of your rig as much as possible, as those are easier to render. You should only use deformations, drawings swaps or frame by frame animation when necessary.
- If you started out using Curve or Envelope deformers or Morphing animations, but end up needing to export a rigged sprite sheet, you must keep in mind that Unitiy does not support Harmony's Curve and Envelope deformers nor its Morphing animations. Hence, you will have to bake those animations into frame-by-frame animations. Unfortunately, this will increase the size of your exported sprite sheet, as each baked drawing on each drawing layer will add a sprite to the sheet.
Keep in mind that only drawings that are exposed in your scene or in other skins for your rig will be exported in your sprite sheet. Hence, you do not need to delete unused drawings to optimize your sprite sheet.