A system and method for generating an estimated volume of activation (VOA) corresponding to settings applied to a stimulation leadwire includes a processor performing the following: determining, for each of a plurality of neural elements, one or more respective parameters characterizing an electrical distribution along the neural element, looking up the one or more parameters for each of the neural elements in a look-up table (LUT), obtaining threshold values for each of the neural elements recorded in the LUT in association with the looked-up parameters, comparing, for each of the neural elements, a value of the leadwire settings to each of the respective threshold value, estimating based on the comparisons which of the neural elements would be activated by the settings, and generating a structure corresponding to a region including the neural elements estimated to be activated.