STEP/IGES support



STEP is the industry standard when it comes to moving between CAD software since it’s the most precise interoperable file available. Since resin printers are that much more precise than FDM printers, they could leverage the extra detail. Could you guys add .step or .iges support to Formware?




Yes it’s sort of planned.
I have 1 library in mind which can do the conversion from STEP to mesh. I just haven’t been able to test the quality of the conversion. Probably later this year.

keep in mind, STEP might ben industry standard; as far as I know it’s not mesh based. Our software is Mesh based (as most 3d printing packages) So you have to do meshing at a certain point in time.

Usually the step from Nurbs -> Mesh is where all the mesh errors arise. And the reason we need al these mesh repair algoritms.
So you can prevent these errors by modelling with your production method in mind and doing the meshing yourself in the CAD package. (which usually has render meshes for your 3d display anyway) This is in our experience with years of CAD and printing the best workflow.

kind regards


Hi guys

Step import would be a great feature.
But thinking a bit deeper about it, tells me it is not really necessary. It does not safe time,
or does not safe a working step.
Exporting the file from CAD into step or into stl (obj) does not change the time needed. I need
to export one time anyway …
And if you buy files from any platform (thingiverse, …) they are most always stl.
The only real benefit in saving time would be a native CAD file import.
And I think this is not necessary here.

Yes, a step file is not a mesh file - it contains information for vectors and curves that are
mathematically defined, and therefore are very precise.
But precision can also be obtained by very high conversion factors for stl conversion.
Formware does handle this big files quite good. So no real problem.

I think there are much more important things to do …
Just my 2cents…

Best regards, Chris


thx for the input!



Reason I asked for STEP support is because I once tried printing some rollers which sounds simple enough, but even on the high quality setting instead of circular shapes, I got these 20 or 30 sided polygons. Sounds like a lot, but it made inserting bearings into them a LOT harder than it should’ve been. I’d like to have the peace of mind (especially with these MSLA printers that can do wonders) that when I ask for a circle, I get a circle and not a polygon, even more when I NEED a circle


Was just curious about this topic. Don’t know what software you were using to export STEP (B-Rep mathematical surfaces) to STL (triangular polygon surfaces) but usually there are options beyond the usual low, med, high settings that let you adjust surface deviation, normal deviation etc. Whatever name they go by in a CAD application they will facet the mathematical surfaces in STEP to much finer detail triangular facets needed for 3D printing. For example in Fusion 360, high settings on a simple model combining a sphere and cylinder gave me about 17000 triangles. However when I added custom settings to max the polygon count I got 422000 triangles. The faceted model was round enough that the limiting factor would be the printer, not the faceted representation.

fwiw (2 cents or so) … I think CAD (B-Rep) data support, in STEP or whatever format, would be massive overkill for Formware. STEP was developed to enable CAD data transfer between proprietary formats found in CATIA, Solidworks, Inventor, Fusion 360, Pro-E etc. With the advent of 3D printing the CAD vendors were forced to support faceted representations of 3D objects and that is a whole new game. They are best equipped to handle that. It is non-trivial and there are so many places it can go wrong (sliver surfaces, miniscule mismatches at tangent surfaces and so on). The translation library to support STEP files from all possible CAD applications would have to be brilliant and Formware would be bound to updates or bug fixes of that library should the need arise.


Hi Chris,

thx for the valuable input.

I guess you are right… it can go wrong on a lot of parts. It’s also a bit why i’m doubting if we should study the step format and do it ourselves if this is such a pain point.
I’ve seen things here in the office go wrong that makes you wonder… a simple cube (.stl) exported from solidworks. The cube has different numerial coords for the same corner in each of the connected facets. And it wasn’t rounding error, there was a lot of difference. so yeah… to be continued…