User Guide

CHAPTER 9
288
3D Compositing
Light and camera layers add the Orient Toward Point of Interest option. For more infor-
mation about this option, see “Understanding camera Transform properties” on page 295
or “Understanding Light Transform properties” on page 300.
Understanding Z scale
Usually, scaling a layer’s Z axis has no effect on the layer because the layer itself has no
depth. However, changing the position of the layer anchor point or establishing a
parenting relationship with other layers adds depth to a layer either relative to its anchor
point, or to child layers. In these cases, scaling a layer’s Z axis will appear to affect the layer.
If the Z-axis value of a layer’s anchor point has been adjusted so that the anchor point rests
somewhere behind or in front of the layer (has a value greater or less than 0) or if the scaled
layer is a parent to other 3D layers, then changing the Z axis of that layer expands or
contracts the area between either the layer and the anchor point, or the parent and child
layers. This contraction or expansion of the area between the anchor point or child layer
and the scaled layer makes the scaled layer or layers appear to change position.
Understanding 3D rotation
You can adjust 3D rotation two ways: changing a layer’s Orientation values, or changing
its X Rotation, Y Rotation, and Z Rotation values.
When you animate any of a 3D layer’s Orientation property values, the layer moves along
the shortest possible rotational path in 3D space (you can smooth this path by changing
the spatial keyframe interpolation to Auto Bezier; see “Changing the interpolation
method” on page 204 for more information). This property is useful for creating natural
and predictable rotations.
When you animate any of a 3D layer’s X, Y, or Z Rotation property values, the layer rotates
along each individual axis. You adjust the number of rotations as well as the angle of
rotation. You can also add keyframes to the layer’s rotation on each axis individually.
Animating using these Transform properties allows for more keyframing options than the
orientation transform property does, but also may result in motion that is less predictable.
This property is useful for creating rotations with multiple revolutions along a single axis.
By default, the rotation tool adjusts rotation by changing the Orientation values. You can
also use the rotation tool to adjust rotation by changing the X, Y, or Z Rotation values.
UG.book Page 288 Wednesday, February 21, 2001 12:05 PM