Importing a 3D scan

GWS50

Is it possible to import a 3D scan into Onshape? I have tried .ply .stl .dxf .3ds but keep getting a blank page.
I use scans quite a lot in my line of work to build mechanical devices in and around and it is quite an important ability for my workflow.

3dexter

+1

GWS50

I am finding that as technology developes I'm using 3d scans quite often, sometimes organic and sometimes geometric. It is a bridge between CAD and the real world. Onshape is looking like it's becoming pretty powerful and I expect to switch to it in the future as my main CAD program but I think that the links that being able to import 3d scans, photographs etc and the ability to produce production drawings are essential. Until that time it is not something I can use professionally. I am looking forward to the future upgrades!

burhop

No, not yet.  I'm looking forward to this as well.

The problem is that scans point clouds are generally turned into STL or other faceted models.  Onshape is only working with precise models right now (e.g. Solid models either from its own Parasolid kernel or from IGES, STEP, etc.)

luis_garcia

This feature will be very welcomed. I also vote for that.
 I need to work from a 3D scan of a body and without this feature is almost impossible to get the shape right. 

andrew_troup

If you don't need to be able to edit the tesselated solid, it seems to me a much easier thing for Onshape to provide an import capability.

In the meantime, is there a viable workflow (using a free or affordable app) to solidify 3D point clouds into parasolid or a similar MCAD format?

3dexter

+1

GWS50

I am finding that as technology developes I'm using 3d scans quite often, sometimes organic and sometimes geometric. It is a bridge between CAD and the real world. Onshape is looking like it's becoming pretty powerful and I expect to switch to it in the future as my main CAD program but I think that the links that being able to import 3d scans, photographs etc and the ability to produce production drawings are essential. Until that time it is not something I can use professionally. I am looking forward to the future upgrades!

frop

The scanner software at work outputs to IGES/STP. I wonder if it would work? All I know is I think our engineers don't like using scan imports (they're really laggy and whatever else idk).

 burhop said:

 (e.g. Solid models either from its own Parasolid kernel or from IGES, STEP, etc.)

luis_garcia

I have tried to convert the scans to IGES file based on Nurbs surfaces but although the import to Onshape works, it only recognizes the thing as a group of surfaces.
The only option then, (once it is imported) is to add thickness to the faces of the surfaces with "thicken" tool and "merge with all" selected (to create one part), this works if you go one by one, for some reason when you add some faces, thickness can not be added and onshape gives and error in the operation. Not sure why or where is the problem with this surfaces.

burhop

If there are tight bends or kinks in the surface you may not be able to offset it or can only do a very small offset.

The other ways to make a solid (in Onshape) is to use the surface to cut a solid then remove one side or the other.  You can also do a replace face.  However, if you have a lot of surfaces this is going to be very tedious work.

andrew_troup

It  seems to me that an offset which thickens a surface uniformly when the thickness is measured normal to the local surface, will self-intersect (hence be mathematically invalid) wherever the local radius of curvature is both concave and less than the offset distance.

The problem would not (it seems to me) be insoluble, but require a sort of boolean union, 'on the fly', to cope with the self-intersection.

Would anyone who knows what the hell they're talking about care to comment on either or both propositions?

kevin_quigley

@andrew_troup what you describe is true, but the practical application of this is complex. I'm not going to pretend I know anything about the coding implications of this but these are generally kernel level functions rather than application level. So basically if Parasolid can't do it, it won't happen.

but here is the thing, anyone who has ever used a mesh based system or voxel based system knows that shelling and thickening, generally, just works. Some high end apps out there mix and match meshes with nurbs. 

In a similar manner, I have had long conversations with developers who were looking to build CAD apps that used multiple kernels (like IronCAD). The idea being if a shell didn't work in one, it would automatically try it in another kernel.

But a more practical solution is often to have tools that do what they can then highlight the areas they fail. SolidWorks shell tool does this, true, most results from this are rough but often good enough for a 3D print or as the basis for a surface rebuild.

My own ideal would be a system that switches between mesh and nurbs on the fly. Meshes for all those freeform, highly detail surface forms, and transitions, and shells, nurbs for the rest. Such systems do exist, in one form or another, but they are £££££

frank_van_der_hulst

OnShape can only import a handful of file formats (ParaSolid, ACIS, STEP, IGES, SolidWorks).

If you have an STL file, you can import it into FreeCAD, then convert Mesh to Solid via the "Part" menu, then export it to a STEP or IGES file, which you can then load to OnShape.

Beware that some meshes don't readily convert into solids.

don

Any news for this topic?

dave_cowden

@don @andrew_troup @kevin_quigley

I'm a Featurescript developer (NOT Onshape employee though).  I would like to help with this-- I'm starting to look at some of these types of problems. 

If you could give me a couple of example files ( nothing too huge please ) of what you'd like to import, I can have a look.

I can certainly import a point cloud, if you scanned using a device that puts those out. but having example formats would be very helpful.

I can also look into interpolating/approximating surfaces. This is a _really_ hard problem, and honestly as @frank_van_der_hulst
pointed out, importing scans is primarily of value to guide the construction of 'real' geometry-- not as a part of the ultimately created object.

Anyway, I'd be happy to try to help.  

bill_macey

Well. We use Solidworks in the company to work with the scans. But I don't like it much. Onshape looks like what I need, so I'd like to try it with my scans at home.
To produce scans I Use Artec studio. It can export in OBJ, PLY, WRL, STL, AOP, ASCII, Disney PTEX, E57 and  XYZRGB, as it mentioned on software's webpage. Can I use Onshape with one of the file formats? Or maybe convert the scans with Solidworks?

NeilCooke

OBJ and STL

Jake_Rosenfeld

https://cad.onshape.com/help/Content/translation.htm