Adobe 12040118 Tutorial - Page 295

Keep in mind the following as you create and animate text and vector graphics for video: You should always preview your movie on the same kind of device that your audience will use to view it, such as an NTSC video monitor. (See Preview on an external video monitor.) Avoid sharp color transitions, especially from one highly saturated color to its complementary color. Sharp color transitions are difficult for many compression schemes-such as the compression schemes in MPEG and JPEG standards-to encode. These compression schemes can cause visual noise near sharp transitions. For analog television, the same sharp transitions can cause spikes outside the allowed range for the signal, also causing noise. When text will be over moving images, make sure that the text has a contrasting border (such as a glow or a stroke) so that the text is still readable when something the same color as the fill passes behind the text. Avoid thin horizontal elements, which can vanish from the frame if they happen to be on an even scan line during an odd field, or vice versa. The height of the horizontal bar in a capital H, for example, should be three pixels or greater. You can thicken horizontal elements by increasing font size, using a bold (or faux bold) style, or applying a stroke. (See Formatting characters with the Character panel.) When animating text to move vertically-for scrolling credits, for example-move the text vertically at a rate in pixels per second that is an even multiple of the field rate for the interlaced video format. Such a rate of movement prevents a kind of twitter that can come from the text movement being out of phase with the scan lines. For NTSC, good values include 0, 119.88, and 239.76 pixels per second; for PAL, good values include 0, 100, and 200 pixels per second. Apply the Autoscroll - Vertical animation preset in the Behaviors category to quickly create a vertical text crawl (for example, a credit roll). To avoid the risk of twitter that comes with vertical motion, thin graphical elements, and fields, consider presenting credits as a sequence of blocks of text separated by transitions, such as opacity fades. Fortunately, many problems with text in video and compressed movie formats can be solved with one simple technique: Apply a blur to the text layer. A slight blur can soften color transitions and cause thin horizontal elements to expand. The Reduce Interlace Flicker effect works best for the purpose of reducing twitter; it applies a vertical directional blur but doesn't blur horizontally, so it degrades the image less than other blurs. Philip Hodgetts provides tips on the Creative COW website for getting the best results when creating text or vector graphics for video. Scripts and expressions for working with text To the top Christopher Green provides a script (crg_Text_from_File.jsx) on his website that creates one or multiple text layers based on the contents of a text file. You can either create one text layer from all of the text, or you can create one layer for each line in the text file. The script also provides options for leading and other spacing. Todd Kopriva provides an example script on the Adobe website that demonstrates the text formatting features available through the scripting interface. Salahuddin Taha provides a script on the After Effects Scripts website that enables entry of Arabic text (which flows from right to left). Michael Cardeiro provides a script on the After Effects Scripts website that makes multiple versions of your compositions using information from a spreadsheet or database. The script goes through your spreadsheet line by line, making a new version of your composition with text layers in the composition receiving text from the spreadsheet automatically. The After Effects Scripts website provides many scripts for working with text. Paul Tuersley provides a script on the After Effects Scripts website that allows you to search for and edit text layers throughout your After Effects project, create your own text style presets, and apply them to multiple layers. Paul Tuersley provides a script on the AE Enhancers forum for importing Substation Alpha (SSA) karaoke files and automatically creating animated text layers from them. Jeff Almasol provides a script on his redefinery website for editing the source text of text layers. Jeff Almasol provides a script on his redefinery website that converts various plain text punctuation into their "smart" typographical representations (for example, (c) is converted to the copyright symbol, ©). Jeff Almasol provides a script on his redefinery website that sets keyframes for the Source Text property of a text layer and sets the values to text from a text file; the keyframes are placed at times specified by layer markers on the text layer. For examples of expressions for the Source Text property, see Writing expressions for source text and MarkerKey attributes (expression reference). Enter point text To the top When you enter point text, each line of text is independent-the length of a line increases or decreases as you edit the text, but it doesn't wrap to the next line. The small line through the type tool pointer marks the position of the text baseline. For horizontal text, the baseline marks the line on which the text rests; for vertical text, the baseline marks the center axis of the characters.