Tài liệu Thiết kế flash với flash cs5 part 46 pdf

ptg Creating Masks Introduction You can create mask layers to show and hide parts o f y o u r artwork on the Stage. A mask works like a window blocking out everything but a certain area that you define. Any shape, symbol or text object can be used as a mask. The shape you place in a mask layer defines the area that will be visible in the linked layers below it. You can animate a mask to reveal the content on a layer in stages or animate the art in the layer beneath the mask. It is useful for spotlighting and con- trolling the shape of the viewable area. Masks are great tools for keeping the boundaries of the art on your Stage neat and controlled. They are also useful for cropping and experiment- ing with different borders and layouts, because you don't have to edit your art, you simply edit the mask. When creat- ing a mask layer, it is important not to mix elements. For example, don't use an editable shape and a group on the same mask layer group everything together or break the groups into editable shapes. For the most consistent results, use ungrouped, editable shapes in the mask layer. 11 11 What You’ll Do Understand Masks Create a Mask Layer Draw a Mask Activate a Mask Edit a Mask Remove a Mask Add Layers to a Mask Animate a Mask Layer 295 From the Library of Wow! eBook ptg 296 Chapter 11 You use a mask in Flash to control what is viewable on a layer. Whatever you paint or draw onto a mask layer defines the viewable area on any layer it is linked to. Essentially, the shape you place on the mask layer acts like a window to the layers linked beneath it. To li n k a l a y e r, y o u si mp l y d r a g i t i n t o th e linked set. When a layer is linked to a mask it displays a tinted icon and is indented under- neath the mask layer. Masks are useful for cropping artwork on the Stage, and animated masks can create interesting visual effects. Understanding Masks Linked layer Draw any shape or shapes on a mask layer to limit the visible area of any layer linked to it. Mask layer From the Library of Wow! eBook ptg Chapter 11 Creating Masks 297 The mask layer and all linked layers must be locked to activate the mask. Shapes drawn on the mask layer define the visible area. From the Library of Wow! eBook ptg 298 Chapter 11 Any layer can be converted into a mask layer. A mask layer only affects the linked layers beneath it, and there is no limit to the number of layers that can be included. Once a mask layer is created, you can drag other layers beneath it to link them. It is important to keep in mind that too much masking can affect performance in the Flash Player, especially when objects in the masked layers or the mask itself are animated. Creating a Mask Layer Create a Mask Layer Create a new Layer in the Timeline or select an existing one. The layer you select will be the one converted into a mask. If you want to mask the selected layer, create a new layer above this layer and select it. Click the Modify menu, point to Timeline, and then click Layer Properties. Click the Mask option from the Layer Type list. Click OK. A blue masking icon appears on the layer. 4 3 2 1 3 1 Layer 2 becomes a mask layer indicated by masking icon. 4 From the Library of Wow! eBook ptg Chapter 11 Creating Masks 299 Click the layer name of the layer directly beneath the mask layer, and then drag the layer slightly up to link it to the mask. TIMESAVER Press Control+click (Mac) or right-click (Win) the Layer Name area of the layer you want to convert into a mask, and then click Mask. When you use this method, Flash converts the layer into a mask and then automatically links it to the layer directly beneath it. 5 Drag layer 1 slightly up until the gray bar appears. This links it to the mask layer. Layer is linked to the mask layer. It appears in the Timeline indented under the mask layer with a tinted icon. Mask layer From the Library of Wow! eBook . ptg Creating Masks Introduction You can create mask layers to show and hide parts o f y o u r artwork on the Stage. A mask works like a window blocking. Layer 295 From the Library of Wow! eBook ptg 296 Chapter 11 You use a mask in Flash to control what is viewable on a layer. Whatever you paint or draw onto