Building a Character - Mastering Unity 2D Game Development - page 58

◦ Smart : This option will try to identify common patterns in the sprites
from the sheet meant for selection. In some cases, it is able to identify
groups that make up a single sprite together.
◦ Safe : This option focuses on tighter regions around each element it iden-
tifies on the spritesheet, thereby making the edges as close as possible.
Grid (manual)
The grid option is a lot simpler with no complex logic. It simply allows you to define (as
the name suggests) a grid over the spritesheet with defined cell sizes by setting the height
and width options, as shown in the following screenshot:
Unity will then automatically identify sprites based on that grid. Note that it will also ig-
nore any blank areas on the spritesheet by default, so keep this in mind if you need them.
Tip
If you do not see a selection box around your sprites, then check your height and width
settings against the original size of the spritesheet. Normally, you will not see anything if
the sizes are too big.
My advice is to start with a smaller size where the grid shows up and alter the width and
height settings upwards until you are happy with the selection on the entire sheet, espe-
cially if you are unsure of the dimensions of each sprite.