Kinesthetic haptic applications employ force feedback on top of graphic and sound modalities to enable the human operator to interact with objects within a virtual world. The force feedback sensation, in particular, is created by a haptic device that displays the forces arising from this interaction. These forces must accurately emulate a real contact interaction, an objective which is commonly referred to as high-fidelity force feedback rendering. To achieve this, the current paper proposes a constrained-based rendering using a virtual tool that comes into unilateral contact with the virtual objects. Unlike common quasi-static or quasi-dynamic formulations in the haptics literature, a truly dynamic physical interaction between the virtual tool and the objects is modeled here. The paper develops analytical formulations for a canonical problem including colliding contact, sustained contact, slip and stick friction. Initial simulation and experimental evaluations show the potential of this method for handling complicated contact scenarios such as those encountered in haptic simulations of spinal or dental surgeries.