Hi Barry, it's probably either a bug or possibly a malformed trim boundary where pieces of the larger underlying surface are incorrectly being targeted in the bounding box calculation.

You might try running ShrinkTrimmedSrf on it to see if that helps.

It's not likely to be from your script code.

If there are any geometric anomalies like self intersecting surfaces or trim boundaries those could be the cause as well.


re:
> However Moi shows the correct sizes in the top right display.

The top right display uses a different method, it's based off of the display mesh so it can be quick.

- Michael