In certain situations, a constrained
object can rapidly roll about its aim vector. Rolling effects can
happen when the aim vector approaches or points in the same direction
or in the opposite direction as the up vector. For more information,
You can avoid rolling
effects by keeping the target vector clear of the world up vector’s
direction. For example, if the world up vector points in the direction
of the scene’s world space Y-axis (the default), you would try to
avoid having the positive or negative Y-axis point in the same direction
as the target vector. You could move the target object(s) as needed,
or perhaps change the target object weights so that the target vector
does not get to close to the Y-axis.
However, if your animation
makes such avoidances impossible, you can prevent rolling by changing
or animating the world up vector.
To change the world up vector for normal
constraints with the Attribute Editor
- Edit the World Up Vector attribute
as described in
Edit normal constraint attributes.
Note that you can also use the Channel Box to
edit the World Up Vector.
To animate the world up vector for normal
constraints with the Channel Box
- You can set keys on the World
Up Vector attribute by using the Channel Box.
To select the World Up Vector attribute,
Edit normal constraint channels.
To set keys on the World Up Vector, select the World
Up Vector channel, -click
it, and select Key Selected form the pop-up
menu that appears.