(2020-04-23, 5:34)N. W. Perry Wrote: I've noticed something even stranger…I just spent a bunch of time cleaning up all the rounding errors in a model with lots of rotation in it, and the simple act of closing and then reopening the program seems to have reintroduced them. It's just a .001 difference, but it means that mirrored pairs of parts might have different decimal values, for example. (Note that I'm referring to relative positions here—the file code hasn't changed so the absolute decimal values are all still correct.)
So what causes the change from simply closing and reopening the file?
I think, and Roland can confirm, that LDCad keeps the full precision for each part's position and matrix in memory as long as the file is open. This practice makes sense to me since it will cut down on rounding errors while you are actively editing the model. Once you close the model, the full precision info is lost and LDCad has to rely on the precision written to the LDraw file itself.