We can create a button with nothing in the Up, Over and Down frames but fill in something for the hit frame we can create a button that is invisible, but will respond to the mouse.
- Start a new Flash ActionScript 3 movie.
- Find a picture you like, or draw one, and import it to the stage.
- Lock the layer with the picture.
- Add another layer above the picture.
- Let's suppose there is a tree in the picture: with the brush, outline the tree and fill it in so that you have a solid shape that covers the tree.
- Double click the tree shape to select both the fill and stroke.
- From the menu select Modify, convert to Symbol.
- Name it BtnTree and select Button for the type.
- Double click the button to edit it.
- Add a key frame to the hit area, so that it contains the tree shape.
- Delete the tree shape from the Up frame.
- Insert a KeyFrame in the Over frame.
- Add text with the word "tree" in a color that will show up against the tree.
- Go back to scene1. The button will appear as a transparent blue shape.
- Test the movie. You do not see a button, but when you move the mouse over the tree, you will see the word tree.
Experiment: Create a movie with a diagram labeled with transparent buttons.