I want to create a button whose clickable area is only specified by a BoxCollider with Unity's new UI (similar to how you would do it from within NGUI). I can't get a Unity Button to work without the presence of an Image component (which ultimately represents the clickable area of the button).
There are two options for you.
1) Keep the image component on the button with a sprite, then set the transparency/alpha on the color to 0.
2) Write a separate script that you attach to a gameobject (Or image/button) that implements the Unity event interface: IPointerClickHandler and inherits from UIBehaviour. IPointerClickHandler is the interface Buttons use to register a mouse click.
If I'm reading this correctly, I think all you need to do is remove the Sprite Renderer component(s) from the GameObject in question. Or -- what if you had a Sprite whose Alpha value was 0? Would that work?
