This paper presents a new approach for the haptic rendering of compliant motions during the execution of virtual assembly task between simple polyhedral objects. The method, based on the task configuration space, analyzes the type of contacts that take place between objects, since this knowledge allows a better haptic rendering when face-face or edge-face contacts occur. Making use of spacial and temporal coherence, the paper presents an efficient procedure to keep track of the current contacts. This allows to comply to the hard temporal constraints of the haptic serve loop. The presented procedures are focused on the haptic rendering during the interaction between convex polyhedra.