# Set up visibility animation

With visibility animation, an object becomes visible or invisible based on a tag value or the result of an expression. When an object is invisible, it cannot be selected. Mouse clicks pass through it to whatever object is underneath.

Visibility animation is available for all objects and overrides an object’s Visible property.

Tip: | If you use a tag’s value to control visibility animation as well as in an expression to control some other aspect of animation, when you set up visibility, set the Expression true state to Invisible. If you do not do this, the object could appear briefly in its design-time location and orientation before animating properly.

## To attach visibility animation to a graphic object

1. Select the graphic object.
2. Choose Visibility from the Animation menu or click the Visibility tab in the Animation dialog box.
3. In the Expression box, type a tag name or create an expression that will return a numeric value.
4. Select whether the object is to be visible or invisible when the expression is true (that is, a non-zero value).

   Tip: | You can use the Object Explorer to search for objects in your display that have animation. Open the Highlight Settings box and select the kind of animation you want to highlight. If a apply visibility animation to a group as well as to individual objects within the group, when the group's visibility is False, that is, the group is invisible, all the objects in the group are invisible, regardless of the animation on individual objects. When the group's animation is True, that is, the group is visible, the visibility of any object within the group is determined by the object's animation.

## Options

- Expression

  Type a tag name or an expression that will evaluate to numeric values at run time. An expression is a mathematical or logical equation that returns a value. It can contain tag names, constants, and mathematical, relational, logical, and bitwise operators. A tag name can be used as an expression.

- Expression True State

  Check whether the object is to be visible or invisible when the expression is true. For visibility animation, if an expression returns a numeric value of 0, the expression is false. If any non-zero value is returned, the expression is true.

## See also

Attach animation to graphic objects

Use the Expression editor

Tag names with animation

Object Explorer

Highlight Settings dialog box