Hi Group, I am writing STL manipulation software and i find, that openscad is a great viewer to look at the output. However in many cases i'd like to have cerain points, edges, faces annotated in the resulting STL, so i dont have to match coordinates. STL File format has 16 extra bits available for each triangle. Is it possible to use these bits to display important points, edges or faces highlighted ? e.g. a cut faces also appears green in contrast to an original face, which appears yellow. Thank you for your inputs.

On 08.04.22 07:48, Guenther Sohler wrote: > STL File format has 16 extra bits available for each triangle. > Is it possible to use these bits to display important points, > edges or faces highlighted ? If you want to use that for internal purposes and files that are not shared with others, that is probably fine. OpenSCAD is unlikely to implement such a non-standard extension. With non-standard being a bit fuzzy as STL is so old that there's not really a good/official specification. ciao, Torsten.

hi Torsten, Thank you for your prompt feedback. Its helpful to me to know that such functionality does not exist, so I don't need to continue to seek the internet and/or openscad source code. Admittedly,STL file format is very old, but it's still used in most cases. When you state STL is a bit fuzzy, what is your preferred/suggested file format to store 3D data ? best regards On Fri, Apr 8, 2022 at 8:49 AM Torsten Paul <Torsten.Paul@gmx.de> wrote: > On 08.04.22 07:48, Guenther Sohler wrote: > > STL File format has 16 extra bits available for each triangle. > > Is it possible to use these bits to display important points, > > edges or faces highlighted ? > > If you want to use that for internal purposes and files that > are not shared with others, that is probably fine. > > OpenSCAD is unlikely to implement such a non-standard extension. > > With non-standard being a bit fuzzy as STL is so old that > there's not really a good/official specification. > > ciao, > Torsten. > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >

On 08.04.22 10:22, Guenther Sohler wrote: > When you state STL is a bit fuzzy, what is your > preferred/suggested file format to store 3D data ? When talking about something similar to STL, for storing mesh data, the best bet seems to be 3MF at this point. https://3mf.io/ I'm not sure if the property extension would support this selection information. ciao, Torsten.