Animation in 3D Invig Pro is done by Sets, as you know.
To place each letter in a separate group, you'll need to select each letter individually.
To select an individual letter in a Text Block, do the following:
- Make sure none of the letters are selected
- Holding the Shift key, click on a letter
- Still holding the Shift key, click on additional letters as necessary
- Select the Set number for the selected letters.