This paper presents a new soft-finger haptic rendering algorithm based on the concept of limit curve which was previously used by the robotic manipulation community to study sliding contacts. The algorithm is more general than the one presented by the same authors in a previous paper since it considers the effects of linear and rotational friction as coupled. However, the solution presented in this paper maintains some of the aspects of simplicity and computational efficiency that characterized the previously proposed solution. To conclude the paper we present a set of simulated interactions between a user and a simple virtual object through a haptic device which allows two point-contact interaction.