Update: I got my
heron done and printed in pwsf. Very pleased with the result. I originally intended it for ceramic, but misread the materials requirements. Ho hum...
Back on the Bounding box topic, I have this model
https://www.shapeways.com/model/883954
Original Bounds: Cm: 8.9 w x 0.5 d x 9.9 h
Oriented Bounds (used for determining printability): Cm: 8.4 w x 0.5 d x 10.0 h
The major surfaces are all horizontal or vertical depending on the orientation in the printer, but my latest print had stepping on it which I could not understand, and certainly could not get explained to me. However I have just realised that the extra width provided by the hanging loop gives scope for tilting the whole piece in the printer some tiny amount, and judging by the above measurements rotating it a bit.
Clever maths/algorithm, I suppose, but is it really necessary in this case, especially when it leaves me open to the dreaded stepping? Once again, has it always been this way or did the changes come in at the same time as the above noted changes?
So, back to your belly button idea, mkroeker - if you want surfaces of your model to be treated as true horizontals or verticals, it may be necessary to game this process by the judicious addition of ... extra bits.