8

808 Chapter 21: User Interface
When the hierarchy is open, you can select a
sub-control, such as a gizmo, and then adjust it.
The available sub-controls vary from modifier to
modifier.
Objects that have a sub-object hierarchy, such as
editable meshes (page 1–984) and NURBS (page
1–1079)
, also show a collapsible hierarchy in the
modifier stack.
To work at a sub-object level, click to open the
hierarchy, then click to select the sub-object
level. Controls for that particular level or type
of sub-object appear in rollouts below the stack
display.
(Certaintypesofsub-objectsdisplayaniconatthe
right of the stack, to help you see which sub-object
type you are adjusting.)
Opening an object’s hierarchy to access sub-object levels
Tool Buttons
Below the stack display is a row of buttons for
managing the stack.
Pin Stack—Locks the stack to the currently
selected object so it remains with that object
regardless of subsequent changes in selection. The
entire Modify panel is locked to the current object
as well.
Pin Stack is useful for transforming another object
while keeping your place in the modified object’s
stack.