When you drag the handle, you can snap to a face or vertex to set the modified feature size.
To snap to a face:
- Select a face and drag the handle.
- Press and hold the Alt key, then move the pointer over the face to which to snap.
A dashed line connects the dragged face to the face you are snapping to.
- Release the mouse button.
Video: Snapping to a Face with Instant3D