Select And Manipulate

Default main toolbar > Select And Manipulate button

The Select And Manipulate command lets you edit the parameters of certain objects, modifiers, and controllers by dragging "manipulators" in viewports.

Note: Unlike Select And Move and the other transforms, this button's state is nonexclusive. As long as Select mode or one of the transform modes is active, and Select And Manipulate is turned on, you can manipulate objects. However, you must turn off Select And Manipulate before you can select a manipulator helper.

These are the features that have manipulators:

IK Solver Properties Rollout (HI Solver)

Reactor Controllers

Target Spot

Free Spot

Spotlight Parameters

UVW Map Modifier

In addition, you can add these custom manipulators to your scene:

Cone Angle Manipulator

Plane Angle Manipulator

Slider Manipulator