> Wim, I'm not sure I understand this rationale.  Somewhere someone is > chaining all the transforms and computing the shallow tree. The shallow tree is only computed once, and then published over tf. So every tf listener can efficiently compute transformations between links. If we publish the more natural tree, then every single tf listener would have to do extra computations to chain links together. > Why not just > publish a more "natural" tree, along with the pre-computed transforms that > go into the shallow tree? I'm not sure I understand what you mean. Tf doesn't allow us to publish the same tree twice. Wim -- -- Wim Meeussen Willow Garage Inc.