This property returns the highest level of geometric continuity the surface possesses. For example, if the surface is G1 continuous everywhere, but not G2 continuous at a specific location, this method returns the level as 1, indicating a G1 continuous surface. Typically, a surface will not count itself as any higher than G3 continuous even if it is continuously differentiable beyond the third derivative. Methods in this interface deal with derivatives only as high as the third. Moreover, if the server cannot determine, or has difficulty determining, its true, highest-continuity rating, it will return a lower level of which it is certain.
