Blended
Choose the Blended option to keep a constant radius at the end of the fillet. This is the recommended choice for closed reference curves. These are curves that start and end at the same location. This helps match the two ends of the fillet surface.
Linear
The Linear option uses a constant rate of change in radius at the ends of the reference curve. The Linear option generally yields better results in fillet surfaces that are not closed.
SURFCAM automatically determines Blended or Linear default parameters.