Ismorphism is hard to detect, even in reduced spaces. Really hard in arbitrary graphs. For a "fast filter" generate the center of gravity for each (just the av

Ismorphism is hard to detect, even in reduced spaces. Really hard in arbitrary graphs. For a "fast filter" generate the center of gravity for each (just the average of the voxel points as doubles) and abs+sort the resulting vector and assume they match if the "Sorted Cog Vector" matches. It will have false positives sometimes but no false negatives.