Chapter 5. Graphics on Multiple Layers

I l @ ve RuBoard

Macromedia Flash MX uses two types of spatial organization: (1) the position of elements within the rectangle that is the Stage and (2) the way elements stack up. You create an illusion of three-dimensional depth by overlapping objects. As you learned in Chapter 4, you can create this overlapping effect on one layer by stacking groups and symbols. The more elements your movie contains, however, the more difficult it becomes to manipulate and keep track of the stacking order of items on a single layer. You can use multiple layers to bring that task under control.

You could think of a Flash animation as being a stack of film: a sheaf of long, clear acetate strips divided into frames . Each filmstrip is analogous to a Flash layer. Shapes painted on the top strip of film obscure shapes on lower strips; where the top strip of film is blank, elements from lower strips show through.

When you place items on separate layers, you can easily control and rearrange the way the items stack up. If you have several elements ”say, a square, circle, rectangle, and star ” each on its own layer, you can play around with which shapes appear to be closer to the viewer by changing the layer order. Placing items on different layers prevents the items from interacting, so you don't need to worry about grouping the items or having one shape inadvertently interact with another.

I l @ ve RuBoard