Abstract: To interpolate admissible G2 Hermite data, this paper proposes a modified
geometric subdivision scheme with new subdivision rules near the end points of the curve. The
method is based on the theory of planar biarc curve interpolation. Theoretical analysis shows that
the limit curves of the modified subdivision scheme are planar spirals, which are curves of
one-signed, monotone increasing or decreasing curvature. Numerical examples show that the
modified subdivision scheme converge rapidly, and the limit curves are with nice shape.

Key words: planar spiral, admissible G2 Hermite data, Hermite interpolation