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• OpenGL-Interactive or OpenGL-Always On OpenGL mode provides high-quality previews that require less rendering time than other playback modes. OpenGL can also be used to speed up rendering to final output. OpenGL features in After Effects rely on OpenGL features of your video hardware. When OpenGL does not support a feature, it simply creates a preview without using that feature. For example, if your layers contain shadows and your OpenGL hardware does not support shadows, the preview will not contain shadows. Select OpenGL-Interactive to use OpenGL only for interactions, such as manually previewing (scrubbing) in the Timeline panel or dragging a layer in the Composition panel. You can tell that OpenGL is engaging by looking at the Fast Previews icon, which will light up. Select OpenGL-Always On to use OpenGL for all previews. In this mode, “OpenGL” will appear in the upperleft corner of each view in the Composition panel.
Note: The Enable OpenGL option in the Fast Previews area of the Preview preferences category must be selected for you to use OpenGL.
To prevent After Effects from updating images in the Footage, Layer, or Composition panels, press the Caps Lock key.
When you make a change that would otherwise appear in a panel, After Effects adds a red bar at the bottom of the panel with a text reminder that image refresh is disabled. After Effects continues to update panel controls such as motion paths, anchor points, and mask outlines as you move them. To resume panel updates and display all changes, press Caps Lock again. Pressing Caps Lock is a good way to prevent views from being refreshed for each frame during rendering for final output.
See also “Render with OpenGL” on page 593
Preview on an external video monitor You can preview the contents of your Layer, Footage, or Composition panel on an external video monitor. This requires additional hardware, such as a video capture card or a FireWire port. If you’re using a video digitizing card to connect an external video monitor, follow the directions that came with your video digitizing card to connect the monitor for viewing previews. If you’re using a FireWire port, first connect a digital camcorder or video tape recorder (VTR) to the port, then connect the video monitor to the camcorder or VTR. For more information on setting up FireWire previews, see the documentation that came with your digital camcorder or VCR.
Whether or not color management is enabled for the project, After Effects does not manage the color of previews on an external video monitor. The colors sent to the external video monitor are in the project’s working color space. For more information, see “Choose a working color space and enable color management” on page 243.
1 Choose Edit Preferences Video Preview (Windows) or After Effects Preferences Video Preview (Mac OS).
2 Choose an external device from the Output Device menu. (If a device is available, it’s automatically listed in this menu.) 3 Choose a mode from the Output Mode menu. The choices listed depend on the device you are using. The Frame Size value that appears under the Output Mode menu is dependent on the value that you select from the Output Mode menu, and is not dependent on any other After Effects settings.
4 Set any of the following options:
Previews Displays RAM previews or standard previews on the external monitor only.
Mirror On Computer Monitor Displays RAM previews or standard previews simultaneously on the external monitor and on the computer screen. This may slow down the previews.
Interactions Displays interactive previews, such as scrubbing in the Timeline panel or dragging in the Composition panel, on the computer screen and simultaneously on the external monitor.
Renders Displays each frame on the computer screen and simultaneously on the external monitor as the frames render in the render queue.
5 Select Scale And Letterbox Output To Fit Video Monitor if you are working with image sizes that don’t match your preview device frame size and you want to see the entire image scaled to fit.
After choosing an output device in the Video Preview preferences, you can preview the current frame on the output device by pressing the forward slash (/) key on the numeric keypad. Press Ctrl+/ (Windows) or Command+/ (Mac OS) to toggle the preference to Desktop Only or to the output device you specified.
See also “Select a 3D view” on page 127 “Work with viewers” on page 19 Select a 3D view You can view your 3D layers from several angles, using orthographic views or custom views that employ perspective.
You can switch views at any time. The orthographic views (Front, Back, Left, Top, Right, and Bottom) show layers’ positions in the composition but do not show perspective.
You can adjust the point of view and direction of view for the custom views with the camera tools.
You can also choose to look at selected layers or all layers. When you do this, After Effects changes the point of view and direction of view to include the layers that you have selected.
• Choose a view from the 3D View menu at the bottom of the Composition panel.
• Choose View Switch 3D View, and choose a view from the menu.
• Choose View Switch To Last 3D View.
• To switch to the previous 3D view, press Esc.
• To see selected layers, choose View Look At Selected Layers.
• To see layers that aren’t visible in the active view, choose View Look At All Layers.
• To select one of the 3D views with keyboard shortcuts, press F10, F11, or F12.
To change which 3D view is assigned to a keyboard shortcut, switch to a view and then press Shift and the shortcut key. For example, to make F12 the shortcut for Top view, switch to Top view and then press Shift+F12. You can also use the View Assign Shortcut To menu command for this purpose.
See also “Working with 3D layers” on page 171 “Cameras, lights, and points of interest” on page 176 “Select a view layout and share view settings” on page 126
Zoom The Magnification Ratio control in the lower-left corner of a Composition, Layer, or Footage panel shows and controls the current magnification. By default, the magnification is set to fit the current size of the panel. When you change magnification, you change the appearance of the pixels in the panel that you are previewing, not the actual resolution of the composition.
Note: After Effects renders vector objects before zooming (scaling for preview), so some vector objects may appear jagged when you zoom in on them. This does not affect scaling of layers or rendering to final output.
• To zoom in to or out from the center of the active view, press the period (.) key or the comma (,) key. Each keypress additionally increases or decreases the magnification.
• To zoom in to or out from the center of the view using the mouse scroll wheel, position the pointer over the panel and move the scroll wheel.
• To zoom in on or out from a specific point using the mouse scroll wheel, position the pointer over the panel and Alt-move (Windows) or Option-move (Mac OS) the scroll wheel.
• To zoom in on a specific point using the Zoom tool, click the area in the panel you want to magnify. Each click additionally magnifies the image, centering the display on the point you click. You can also drag the tool to magnify a specific area.
• To zoom out from a specific point using the Zoom tool, Alt-click (Windows) or Option-click (Mac OS) the point that you want to be the center of the zoomed-out view. Each click additionally decreases the magnification of the image, centering the display on the point you click.
• To zoom the active view to 100%, double-click the Zoom tool button in the Tools panel.
• To zoom to fit or to zoom to a preset magnification, choose a zoom level from the Magnification Ratio menu. To change the magnification of all views in a Composition panel, hold down Ctrl (Windows) or Command (Mac OS) while choosing a zoom level from the menu. Choose Fit to make the image fit the Composition panel; choose Fit Up To 100% to limit the zoom level to 100%.
To pan around in the Composition, Layer, or Footage panel while zoomed in, drag with the Hand tool, which you can activate by holding down the spacebar or the H key.
See also “Shortcuts for using and modifying views” on page 644
You can choose from the following Resolution settings in the Composition Settings (Composition Composition
Settings) dialog box or at the bottom of the Composition panel:
Full Renders each pixel in a composition. This setting gives the best image quality, but takes the longest to render.
Half Renders one-quarter of the pixels contained in the full-resolution image—half the columns and half the rows.
Third Renders one-ninth of the pixels contained in the full-resolution image.
Quarter Renders one-sixteenth of the pixels contained in the full-resolution image.
Custom Renders the image at the resolution you specify.
Viewing a color channel or alpha channel You can view red, green, blue, and alpha channels—together or separately—in a Footage, Layer, or Composition panel by clicking the Show Channel button at the bottom of the panel and choosing from the menu. When you view a single color channel, the image appears as a grayscale image, with the color value of each pixel mapped to a scale from black (0 value for the color) to white (maximum value for the color).
To see color values displayed in the channel’s own color instead of white, choose Colorize from the Show Channel menu.
When you preview the alpha channel, the image appears as a grayscale image, with the transparency value of each pixel mapped to a scale from black (completely transparent) to white (completely opaque).
Note: When you choose RGB Straight, which shows straight RGB values before they are matted (premultiplied) with the alpha channel, pixels with complete transparency are undefined and therefore may contain unexpected colors.
You can view other channel values, such as saturation and hue, by applying the Channel Combiner effect and choosing Lightness from the To menu.
To switch between showing the alpha channel and showing all RGB channels, Alt-click (Windows) or Option-click (Mac OS) the Show Channel button.
See also “About alpha channels and mattes” on page 252 “About straight and premultiplied channels” on page 253 “Shortcuts for using and modifying views” on page 644 “Channel Combiner effect” on page 383
The Adjust Exposure control is useful for finding the black point or white point in an image. For example, drag the value control to the right (positive values) until the entire image is white except for one area; that area is the darkest area in the image.
• To adjust exposure for a viewer, drag the Adjust Exposure control to the left or right, or click the control and enter a value in the text box.
• To reset exposure, click the Reset Exposure button. To return to the most recent non-zero setting, click the button again.
See also“Exposure effect” on page 397
Work with safe zones, grids, guides, and rulers In the Footage, Layer, and Composition panels, you can display safe zones, grids, rulers, and guide lines to align and arrange visual elements. After Effects preserves guides when importing Photoshop files saved with guides.
Television sets enlarge a video image and allow some portion of its outer edges to be cut off by the edge of the screen.
This is known as overscan. The amount of overscan is not consistent between television sets, so you should keep important parts of a video image within margins known as safe zones. The conventional action-safe zone is 90% of the width and height of the frame; keep important visual elements within this zone. The conventional title-safe zone is 80% of the width and height of the frame; keep text that you intend for the audience to read within this zone. Safezone margins represent the percentage of image dimensions not included in the safe zone. You should always design from one edge of the frame to the other, because computer monitors and some television sets may show the entire frame.
Grids, guides, and rulers can help you to arrange and align layers. The size of proportional grids increases or decreases when the composition size changes; the size of standard grid squares remains the same regardless of composition size.
You can change the origin, or zero point, in both rulers. The position of the pointer measured from the new zero point is shown in the Info panel as X’ and Y’ coordinates.
Grids and guides are not rendered, either for RAM previews or for final output.
AFTER EFFECTS CS3 131 User Guide
Composition panel’s zones and grids A. Grid B. Title-safe zone C. Action-safe zone D. Overscan
• To change the portion of the composition marked as title-safe or action-safe, as well as other options for grids and guides, choose Edit Preferences Grids & Guides (Windows) or After Effects Preferences Grids & Guides (Mac OS).
• To show or hide safe zones, grids, guides, or rulers, click the Grid And Guides Options button and choose the appropriate menu item, or use a menu command or keyboard shortcut in the View menu.
• To toggle between showing and hiding the safe zones, Alt-click (Windows) or Option-click (Mac OS) the Grid And Guide Options button.
• To make layer edges and mask edges snap to grids or guides, choose View Snap To Grid or View Snap To Guides.
• To create a guide line, drag from either ruler.
• To delete a guide line, drag it to a ruler using the Selection tool.
• To delete all guide lines, choose View Clear Guides.
• To move a guide line, drag it using the Selection tool.
• To lock or unlock guides, choose View Lock Guides. Locking a guide prevents it from being accidentally moved.