Aligning Sprites on the Stage
To make your movie look neat and professional, you'll often want to align sprites cleanlyor distribute them evenlyacross the Stage.
You can do either of these things by using the Align command. You can align sprites with respect to their centers, registration points (see "To view and set a cast member's registration point" later in this chapter), or any of the eight points around the bounding box that encompasses each sprite. Aligning sprites does not change their cast members ' registration points.
You can use the Tweak command when you need to move sprites a precise number of pixels on the Stage.
When you construct an animation sequence from multiple cast members, the sprites may appear to jump or shift from one frame to the next . To eliminate this jerky motion, you can adjust the cast members' registration points. Every bitmapped cast member in your movie has a default registration point directly at its center ( Figure 3.68 ).
Figure 3.68. Cast members from an animation sequence of a flying bat. The registration point for each cast member is at its center (the default position). As a result, the bat's movements may not look smooth from frame to frame.
If you are animating several frames of an athlete running, for example, you could reset the registration point for each cast member to the point where the character's feet touch the ground, to ensure that the runner's feet never hit above or below ground level.
To align sprites:
In the Score or on the Stage, select all the sprites that you want to align ( Figure 3.69 ).
Figure 3.69. Select the sprites you want to align.
Choose Modify > Align to display the Align panel ( Figure 3.70 ).
Figure 3.70. The Align Sprites panel.
In the Align panel, click one of the icons to specify how the sprites should aligned or distributed.
The sprites line up in relation to the last sprite you selected ( Figure 3.71 ).
Figure 3.71. Sprites align with respect to the last sprite selected.
To tweak a sprite:
Select a sprite in the Score or on the Stage.
Choose Modify > Tweak.
The Tweak panel opens ( Figure 3.72 ).
Figure 3.72. Use the Tweak panel when you want to move sprites a specific number of pixels.
Drag the image in the left side of the Tweak dialog box to specify visually how far to move the selected sprite.
Click the up and down arrows to specify how far (in pixels) to move the selected sprite in horizontal and vertical directions.
Click Tweak to move the sprite.
To view and set a cast member's registration point:
Double-click a visual cast member in the Cast window.
If the cast member is a bitmap, it will open for editing in the Paint window; if it's a vector shape, it will open in the Vector Shape window.
Select the Registration Point tool ( Figure 3.73 ).
Figure 3.73. The Registration Point tool in the Paint window.
The current registration point appears at the intersection of the dotted lines.
Move the crosshair pointer where you want to place the new registration point, and click ( Figure 3.74 ).
Figure 3.74. The same bat cast members, with the registration point moved to the center of each cast member's head. The bat's head will now remain steady while the wings flap.