2009

On and Off Visibility
When you first assign a visibility track to an object, a Bezier float controller
is automatically assigned; this allows gradual visibility. You can make an object
appear or disappear suddenly by changing the interpolation of the visibility
keys to Step tangency.
Variable opacity is supported in the shaded viewports. For ease of use, the
object never completely disappears from the viewports.
Visibility Inheritance
An object can inherit the visibility of its parent (as determined by the parent's
Visibility track in the Track View). Use the Object Properties > Inherit Visibility
check box to specify the visibility inheritance of an object.
Groups and Visibility
All members of a Group inherit the visibility of the parent when a visibility
controller is assigned to the parent. Transparent materials and hidden objects
have no effect on this function.
Level of Detail Utility and Visibility
The
Level of Detail utility on page 2579 lets you construct an object that alters
its geometric complexity or level of detail based on its size in the rendered
image. You create several versions of the same object each with different levels
of detail; you group them as one, and then assign the Level of Detail utility.
This automatically creates a special LOD controller as a Visibility track.
Procedures
To add a visibility track to objects:
1 In Track View Curve Editor or Dope Sheet Edit Keys mode, highlight the
object you want to affect in the Hierarchy list on the controller window.
2 From the Track View > Tracks menu, choose Visibility Tracks > Add.
3 Select the keys then use Controller > Properties to adjust the key values
and interpolation.
A value of 0 creates an invisible object, a value of 1.0 creates a fully visible
object. Change the interpolation to step for sudden visibility, rather than
gradual fades.
3612 | Chapter 15 Animation