A method for generating a computer model of an airfoil including an aerodynamically-shaped fillet, the method comprising: inputting a 2D image of an airfoil having an airfoil surface line and including a transition region interconnecting the airfoil surface line to a flowpath surface line with a 2D fillet curve; generating a plurality of flowpath offset lines (26, 26-1...26-5) on the 2D image at pre-determined flowpath offset values, each flowpath offset line (26, 26-1...26-5) of the plurality of flowpath offset lines (26, 26-1... 26-5) in the transition region graphically representing a flowpath offset surface of a plurality of flowpath offset surfaces; determining an intersection point between the 2D fillet curve and each flowpath offset line (26, 26-1...26-5); computing a distance between the airfoil surface line and each intersection point to generate a plurality of airfoil offset values; generating a plurality of airfoil offset surfaces on the computer model of the airfoil being generated according to each airfoil offset value of the plurality of airfoil offset values; generating the plurality of flowpath offset surfaces on the computer model of the airfoil being generated according to each flowpath offset value; and generating a plurality of 3D fillet streamline curves (27, 27-1...27-5) to define the aerodynamically-shaped fillet on the computer model of the airfoil being generated, each 3D fillet streamline curve (27, 27-1...27-5) comprising an intersection between an airfoil offset surface of the plurality of airfoil offset surfaces and a flowpath offset surface of the plurality of flowpath offset surfaces, wherein generating the plurality of 3D fillet streamline curves (27, 27-1...27-5) comprises replicating at least one inflection from the airfoil into the aerodynamically-shaped fillet, wherein the at least one inflection comprises a change in camber, a change in twist, a leading edge shape or angle, a trailing edge shape or angle, or combinations thereof; outputting the computer model of the airfoil including the aerodynamically-shaped fillet. inputting a 2D image of an airfoil having an airfoil surface line and including a transition region interconnecting the airfoil surface line to a flowpath surface line with a 2D fillet curve; generating a plurality of flowpath offset lines (26, 26-1...26-5) on the 2D image at pre-determined flowpath offset values, each flowpath offset line (26, 26-1...26-5) of the plurality of flowpath offset lines (26, 26-1... 26-5) in the transition region graphically representing a flowpath offset surface of a plurality of flowpath offset surfaces; determining an intersection point between the 2D fillet curve and each flowpath offset line (26, 26-1...26-5); computing a distance between the airfoil surface line and each intersection point to generate a plurality of airfoil offset values; generating a plurality of airfoil offset surfaces on the computer model of the airfoil being generated according to each airfoil offset value of the plurality of airfoil offset values; generating the plurality of flowpath offset surfaces on the computer model of the airfoil being generated according to each flowpath offset value; and generating a plurality of 3D fillet streamline curves (27, 27-1...27-5) to define the aerodynamically-shaped fillet on the computer model of the airfoil being generated, each 3D fillet streamline curve (27, 27-1...27-5) comprising an intersection between an airfoil offset surface of the plurality of airfoil offset surfaces and a flowpath offset surface of the plurality of flowpath offset surfaces, wherein generating the plurality of 3D fillet streamline curves (27, 27-1...27-5) comprises replicating at least one inflection from the airfoil into the aerodynamically-shaped fillet, wherein the at least one inflection comprises a change in camber, a change in twist, a leading edge shape or angle, a trailing edge shape or angle, or combinations thereof; outputting the computer model of the airfoil including the aerodynamically-shaped fillet.