Manipulators of Rounding with Variable Radius

Radius manipulators have a shape of a blend surface's cross-section (arc) with two square markers at endpoints.

Quantity of manipulators for each edge (or edge chain) depends on the quantity of radius change critical points. By default at least two points are created - start and end. On open edges an individual manipulator appears for each point. Start and end points of closed edges have a common manipulator, due to necessity of having equal radii at such points (otherwise blend could not be created)

Moving the mouse cursor over any of a manipulator's endpoint markers leads to radius icon appearing near the cursor. Dragging the mouse while holding, when radius icon is present, leads to blend Radius value change in accordance with the cursor movement. Depending on the Common Properties checkbox condition, Radius changes either for all edges at once (which affects the appearance of their manipulators) or for the corresponding edge only. Both endpoint markers of a single manipulator work in the same way - it doesn't matter which one to use.

On intermediate points besides from radius manipulators, point position manipulators appear. They look like an unfilled contour ( - active, - inactive) and are located a bit aside a corresponding radius manipulators. Sometimes point position manipulator might appear relatively far from corresponding radius manipulator.

Moving the mouse cursor over a point position manipulator leads to a point position icon appearing near the cursor. Dragging the mouse while holding, when point position icon is present, leads to Position (%) of the corresponding point change in accordance with the cursor movement. Depending on the Common Properties checkbox condition, Position (%) changes either for all edges at once (which affects the position of their manipulators) or for the corresponding edge only.