or indirect interactions with neighboring hairs. For example, consider three hair.....that are aligned in a row, as in Figure 13 left. We can prune the interaction ....and assume that the effect of this interaction will happen through contacts between... and.... . As the numbers of hairs increase, the effects of these individual hair-hair interaction become less important as we mainly see the aggregate effects of many hair-hair interactions. Using this observation, we have developed an algorithm to prune hair pairs used for contact testing effectively sampling the hair-hair interactions. This pruning allows us to reduce the number of necessary hair-hair contacts, reduce interprocessor communication and more efficiently parallelize the simulation.