195doublee; /* corresponding edge curve parameter (ON_UNSET_VALUE if using trim not edge) */
196ON_3dPoint *p3d; /* 3d edge/trim point depending on whether we're using the 3d edge to generate points or the trims */
197ON_3dPoint *n3d; /* normal on edge, average of the normals from the two surfaces at this point, or of all surface points associated with a vertex if this is a vertex point. */
198ON_3dVectortangent; /* Tangent from the curve, or from the surfaces if the curve wasn't usable at this point. */