A system comprises a user input device configured for receiving an electrode morphology having an electrode, memory storing at least one basis electrode model, and a processor configured for modeling the electrode by recalling the at least one basis electrode model from the memory, and using the recalled at least one basis electrode model multiple times to construct a model of the electrode. Another system comprises a processor configured for estimating at a plurality of spatial points a respective plurality of electrical field vectors resulting from a stimulation lead operating in accordance with the set of stimulation parameters, determining an amplitude of each electrical field vector and an angle between each electrical field vector and a vector aligned with an axis of the stimulation lead, and estimating a tissue of volume activation about the stimulation lead based on the determined amplitude and angle of each electrical field vector.