Hi all, I am working on processing some data stored in a bag file. I am not sure if this is a silly or naive question, but my searching thus far has not led very far. Here's the situation: I have my tf messages stored in a bag file. The tf values for different frames do not change over time (rigid system). I know the names and transforms for the frames since this is stored in the bag data. What I would like to do is get the same functionality from lookupTransform() without needing to publish my transforms and listen form them to get the calculations performed by this function. It would be excellent to achieve this python, since this is language that my processing code is using. Thanks!