Does anyone know of a good file converter? I’d like to convert an STL file to anything 3D model that Shapr3D can import (X_T, STEP, IGES, etc.).
Thanks, Mike
Hello Mike! Someone referred me to MeshMan3D sometime back. McD
Hi Tom,
Nice to hear from you. Thanks for the tip, I’ll give it a try.
-Mike
Fusion 360 can do it if the mesh is not too complex.
Thanks for the input.
-Mike
Hi @TigerMike,
The way to convert an STL (or any mesh file) to a CAD model that can be edited flawlessly is the process of reverse engineering. Even with suitable software it can only be partially automated in the case of detailed models. It mostly guides the user by helping to find planar or cylindrical surface elements by applying refined algorithms to provide fewer possible inaccuracies compared to the mesh model. Do not get me wrong, they are extremely helpful, but not making the process as simple as clicking on a Convert button.
If you give a try to any of the mesh to brep converters, you will see that they do almost the same thing: replace the mesh polygons with tiny triangular surface elements. At the end of the process, the model will still not have curved edges or surfaces, but at least it will be defined as a CAD model, not a mesh one.
Reverse engineering can be done fully manually using appropriate surface modeling software that can project and intersect meshes. If vertex snap is possible, that could help a lot, but the process will take a significant amount of manual labor.
With the spread of SubD modeling, another solution appeared but that results in a lot of possible inaccuracies: if the triangular mesh can be converted to a quad mesh, then it can be converted to the SubD model. Well, what could go wrong with the conversion of a converted file 
Long story short, converting a CAD file to a mesh model is just a few taps like an STL export in Shapr3D. Converting a mesh model to a proper CAD file sounds like labor 
4 Likes
Hi KPeter,
Thank you for the reply. Valuable information!
Best regards, Mike
Tiger for what it’s worth, part of my profession is dealing with just this, taking point clouds and STLs and converting them into useable CAD data. Take this as your stock “old man cautioning you to turn back.” If you have any, any other avenue of getting your data other than the way you are trying to do it now, I advise you to think hard on pursuing that path first. Depending on the complexity of the part and “quality” of the STL (whether it originated from a model itself or if it is a true scanned STL), it could easily be much more work trying to reverse engineer and massage that file into being right than it would be recreating the part whole cloth with calipers and an empty page.
What you ask can be done, but STL’s aren’t really made with this in mind. They’re kind of a one-way file, and to reconstruct one well into an actual model isn’t always a pretty process even with some of the expensive dedicated software that we’ve used.
Don’t wish to rain on ya tiger, but those are 2c from someone that’s had to do it a fair few times with true “scanned” STLs. One made from a model may be different, more perfect and easier to reconstruct, but STL’s as a format are fundamentally made to pack as much face geometry data in as small a package as possible, and this means that they aren’t really designed to “translate” back into a proper model very truly or easily :\
4 Likes
Hi @Spencer.G,
Very informative. The STL file I am working with was made from scratch and is quite clean. For me it is usable where I can do some booleans like punch holes, etc. Of course I would have preferred a CAD file so I could more things dimensionally.
In the past I have actually reversed engineered a rather simple STL file or two, but organic shapes are tedious at best.
I feel more educated on this topic, again thanks.
-Mike
Yessir. Pleasure to help. Scale is important as well. Simple STLs can be translated pretty regularly, but complexity and difficulty scale nightmarishly and fast. Overall, I would urge you to avoid them as source materials like the plague, but sometimes you got what ya got to work with
In my opinion Shapr needs its own STL converter. Converting and importng a STEP is just not working well but Shapr itself could do a very good job in making it a parasolid. Would be a gamechanger.
Fusion can convert an stl into a parametric object if imported as a net and then it can be exported as a STEP which can be imported to Shapr.
Why is Shapr incapable to convert to parametric?
Probably because it’s not trivial. Think of solid bodies as mathematical equations and meshes as a series of discrete solutions to those equations in the form of triangles. If you have the equation 2 + 2 and solve it, you get 4. However, if you have the solution of 4, there are an infinite number of equations that will give that result. It’s not quite that difficult, but there’s a lot of geometry to process going from surface triangles to solid bodies. You have to get the paid version of Fusion, using the Prismatic option, to get even close to a clean solid body when converting a mesh
The parametric process is extremely fast, there doesn’t seem to be endless calculation involved and the outcome is a really good enough STEP for use in Shapr. The parametric conversion is really good. Being able to cut and paste an stl in Shapr is just useless. But you are having a point there, Shapr is a paid version and should have the option for parametric conversion!
True, but $240USD/yr vs $1,465USD/yr is a pretty big cost difference, especially for a program that’s been around for a fraction of the time. I just hope shapr doesn’t try to compete directly and end up costing the same.
It’s fine as long conversion is possible for free in Fusion. Stl is no no dead end right now thanks to Fusion. Just making clear its very possible.
It can be done in FreeCAD as well to my knowledge.
I just tried it. Exporting an STL to STEP in FreeCAD did not work. FreeCAD acted like it did, but no file was created.