conversion of file types.
.obj and .stp are not necessarily compatible as both usually contain different types of geometry.
.obj usually contains meshes, most common quad meshes. But is can also contain. triangulated mesh.
,.stp usually contains solid geometry.
If you can share more information about the .obj file or if you can share the file (zip and attach) we can look into it further.
The problem is not the filetype, or file extension. The problem is the data they contain.
.obj is a mesh file and .stp is usually a solid model. Both are different mathematical representations and they are not necessarily compatible.
The first thing you need to find out is I that .obj file is a triangulated mesh, or a quad mesh.
Then we need to know the number of polygons involved.
Is this prismatic or more mechanical geometry , or is it more organic and regular ?
That sounds like scanned geometry ?
You failed to answer an essential question:
Is this prismatic or more mechanical geometry , or is it more organic and regular ?
What is it you want to do with the .stp file ?
The likelihood that you can go through a direct conversion from a mesh to a BRep and then do something with particularly in Fusion 360 is pretty small to say the least!
Based on your answer to the question I repeated, I might be able suggest workflows, but this is not simple stuff.
@Anonymous wrote:
So what's the best way to proceed?
Answering my questions 😉
Is this prismatic or more mechanical geometry , or is it more organic and regular ?
Of course that helps!
You should be very happy following the steps in this tutorial, which I created a few weeks ago specifically to address this sort of thing. Also if you do this more often, you should definitely add Autodesk Meshmixer to your tool shed.
Scanned geometry can have defects that MeshMixer can help repair.