Hi all, especially Sam, Is there a good way to share boundary conditions between nodes of the kD-tree? I'm particularly interested in either speeding up vertex value generation or storing an additional layer of values that correspond to (expensive to compute) values on other processors, for the purposes of the contour finder. Basically, I think we can parallelize the contour finder in yt-3.0 PR 120 if we can share boundary conditions between processors. But, I'm not sure how to do that. Alternately, if we could double-count boundary nodes between processors, that would work as well. For instance, if processors 1 has a tile that borders a tile from processor 4, that tile would be "owned" by 4 but would be replicated on 1. Any ideas? -Matt