Talk:STL (file format)

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Contents 1 Export Controls in Pro/E 2 Format Quality 3 Color STL files 4 Infobox

[edit] Export Controls in Pro/E

What does Angle Control do? That's one of the values I can set when exporting STL with Pro/ENGINEER. --84.115.129.76 09:35, 28 July 2006 (UTC)

That's not a part of the file format itself - it probably controls some kind of automatic mesh simplification in that software. SteveBaker 19:01, 20 November 2006 (UTC)

[edit] Format Quality

Urgh! Where in this article do we get to say "STL is one of the crappiest file formats on the planet"?! SteveBaker 19:01, 20 November 2006 (UTC)

Nowhere, since that's WP:NPOV. There has been discussion about replacing the format with something else, but from the geometry I've seen, STEP or IGES files are no easier... And a format that's not up to that level of complexity probably won't be an improvement. --GargoyleMT 04:08, 21 November 2006 (UTC)

Yeah - I know it's POV - and probably OR also. It was a rhetorical question. To be honest, I don't see the need for a 'special' file format for stereolithography in the first place - just use Collada or something. SteveBaker 15:33, 21 November 2006 (UTC)

Besides historical reasons? I can't find the launch date for the SLA/190, but I think it was mid-to-late 1980s. The STL format has been around at least as long as that stereolithography machine. --GargoyleMT 22:54, 21 November 2006 (UTC)

[edit] Color STL files

Technically both SolidView and Magics have color representation in (binary) STL files. Both of different incompatible formats, even. --GargoyleMT 04:08, 21 November 2006 (UTC)

Do you know the details? It would certainly be worth adding that to the article. (Also, I'm in the process of writing some STL handling software and I'd like to be able to read and write colour information). SteveBaker 15:29, 21 November 2006 (UTC)

I do not know the details off the top of my head. There have been a few posts about it on the RP-ML list. I know from experience that Magics and SolidView use different color formats; there may be more than just those two. --GargoyleMT 23:00, 21 November 2006 (UTC)

Hmmm - OK, I'll see what I can find out (I'm actually already subscribed to that mailing list - so I'll just ask again there). The binary STL format has a two-byte field at the end of every triangle record that claims to be the length of the auxiliary data for that triangle. Every binary STL I've found "in the wild" has had zeroes in those two bytes - but presumably one could put something other than zero there and have the reasonable expectation that loaders will skip that number of byte before attempting to read another triangle. That would allow colour information to be included for each triangle. But what format that's in is anyone's guess. SteveBaker 06:10, 22 November 2006 (UTC)

I have added the colour STL information - YUK! SteveBaker 14:48, 23 November 2006 (UTC)

[edit] Infobox

STL
File name extension	.stl