Interaction icons are a way of letting the player distinguish between different ways of interacting with Hotspots. For example, an NPC can rely on the "Talk to" interaction, while a door might have "Use" and "Look at" interactions.
AC's default interaction types consist of Look at, Use, and Talk to. They are defined in the Cursor Manager's "Interaction icons" panel:
To create a new Interaction type, click "Create new icon" beneath this list and supply its details:
This new Interaction type will now be available in the Cursor / icon field of Hotspot "Use interactions" Inpsectors:
How the player chooses between the available Interactions will depend on the game's Interaction method, as set in the Settings Manager. The possible values of this field are described here, but an Interaction menu is typically involved. AC's default Interaction menu is available in the Menu Manager, and includes separate Interaction elements for each of the default Interaction icons:
If your game makes use of the Interaction menu, then an Interaction icon added to the Cursor Manager will also need to be added to this Menu. The easiest way to do this is to copy one of the existing elements: click the cog icon beside the Look element and choose Copy, then click the cog icon again and choose Paste after:
This new element's properties can then be amended to reference the newly-created Interaction icon:
If the Interaction menu's Source is set to Unity Ui Prefab, then its linked UI prefab will also need to be updated. In the Menu's list of properties, click on the Linked Canvas prefab field value to select the InteractionUI asset file in your Project window. Double-click this asset to open it up in Prefab Mode. Its Hierarchy similarly has Buttons for each of AC's default Interaction icons:
Duplicate the btnLook object and amend it to reflect the new icon. We then just need to link this new Button to the Menu Manager. To do this, select the new Interaction element you just created in the Interaction menu, and drag the new UI Button object into this element's Linked UI Button field. This field will then generate and record that Button's Constant ID value:
A dedicated tutorial on linking Unity UI to AC's Menu system can be found here.