3D model representation using irregular triangulated surfaces has become a powerful tool for modeling complex geologies. Often however, hybrid approaches have to be used to update those models, as algorithms depend on the smoothness of the surfaces, its normals and even its second derivatives. Especially to guarantee continuity of the second derivatives (curvature) is a difficult task. Existing interpolation algorithms are often highly ineffective for computer applications. There here proposed algorithm is an effective linear interpolation of curvature, similar to the successful used linear interpolation of normals on such surfaces.