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## Time slider annotation objects

Figure 15

Figure 16

Time slider annotation objects, shown in figure, are created by clicking the Time slider button in the Create new area on the Objects tab. Time slider annotation objects consist of a graphic that shows the progress through an animation using animation and text that shows the current database time. Time slider annotation objects can be placed anywhere in the visualization window and you can set their size, text, colors, and appearance properties.

Time slider annotation objects are placed using 2D coordinates where the X, and Y values are in the range [0,1]. The point (0,0) corresponds to the lower left corner of the visualization window and the point (1,1) corresponds to the upper right of the visualization window. The 2D coordinate used to position the text annotation matches the text annotation's lower left corner. To position a text annotation object, enter a new 2D coordinate into the Lower left text field. You can also click the down arrow next to the Lower left text field to interactively choose a new lower left coordinate for the text annotation using the screen positioning control, which represents the visualization window.

The size of a time slider annotation object is controlled by settings its height and width as a percentage of the vis window height and width. Type new values into the Width and Height spin buttons or use the +/- arrows next to the Width and Height spin buttons to set a new width or height for the time slider annotation object.

You can set the text displayed by the time slider annotation object by typing a new text string into the Text label text field. Text is displayed below the time slider annotation object and it can contain any message that you want. The text can even include wildcards such as $time, which evaluates to the current time for the active database. If you use $time to make VisIt incorporate the time for the active database, you can also specify the format string used to display the time. The format string is a standard C-language format string (e.g. "%4.6g") and it determines the precision used to write out the numbers used in the time string. You will probably want to specify a format string that uses a fixed number of decimal places to ensure that the time string remains the same length during the animation, preventing distracting differences in the length of the string from taking the eye away from the visualization. Type a C-language format string into the Time format text field to change the time format string.

Time slider annotations have three color attributes: start color, end color, and text color. A time slider annotation object displays time like a progress bar in that the progress bar starts out small and then grows to the right until it takes up the whole length of the annotation. The color used to represent the progress can be set by clicking the Start color button and choosing a new color from the Popup color menu. As the time slider annotation object shows more progress, the color that is used to fill up the time that has not been reached yet (end color) is overtaken by the start color. To set the end color for the time slider annotation object, click the End color button and choose a new color from the Popup color menu. Normally, time slider annotation objects use the foreground color of the vis window when drawing the annotation's text. If you want to make the annotation use a special color, turn off the Use foreground color check box and click the Text color button and choose a new color from the Popup color menu.

Time slider objects have two more attributes that affect their appearance. The first of those attributes is set by clicking on the Rounded check box. When a time slider annotation object is rounded, the ends of the annotation are curved. The last attribute is set by clicking on the Shaded check box. When a time slider annotation object is shaded, simple lighting is applied to its geometry and the annotation will appear to be more 3-dimensional.