Masking a Picture
Masking in flash is a very simple process that produces some great effects. The one thing to remember in flash is that you see THROUGH any mask that you create. When you create a mask layer what ever is below the mask layer is hidden except for where the mask is, you see through the maks.
In this exercise you will import an image and then create a mask layer and mask object. You will then animate the mask. When you are finished you will have something that looks like this.
1. Create a new layer called Picture. Import any picture onto the stage. You may want to make the stage match the dimensions of the picture.
2. Create a new layer called Mask. Right click on the mask layer and select Mask. Notice that a mask icon now appears on the mask layer and one similar appear on the photo layer. The one thing to remember is that the mask layer must always be directly on top of the layer it masks.
3. In the mask layer create a rectangle that is about 1/3rd the width of your picture (or create any shape you want but remember this shape is what you see through) and move it so it covers part of the picture. Save your file and test your movie. You should see the part of the picture that is under the mask.
4. Now animate your mask, create a motion tween so the mask moves across the picture, gets bigger and then stops over a part of the image you want to focus on. Remember to insert keyframes for both the mask and image.
5. Show your mask animation to your instructor for teacher check.