If you want materials, normals and UV maps, etc. then you would need to convert to either OBJ or FBX. Personally I will use FBX for things that might be animated later in an engine like Unreal and OBJ for rendering with colors because of the UV map. Both have their trade offs mostly owing to conversion to a mesh. STEP is useful because it maintains a solid geometry, which is what MCAD depends on. But like the thread Günther posted, it lacks more than a color property. Adding colors is something we can consider but since colors don’t give you a “scene” (camera position, lighting, angle of light, etc) it won’t be sufficient for high fidelity rendering. It will however be an easy way to swap between CAD system which is what it was intended for. Because the Boolean operations on solid geometry are complex, STEP has its place and is a decent but imperfect format. FBX is what used to be known as Filmbox and is very very detailed on the “view” with intention of rendering or using in a “scene”. OBJ is somewhere in between. I would experiment with OBJ and FBX a bit and see if that isn’t helpful. Truly, it will depend on what you are aiming for - geometric or visual accuracy. Tesselation can cost you edge-detail at times but is how UV maps are constructed (for the most part) and that suits good rendering. The ideal for rendering is to also have normal maps, an albedo map, materials, lighting, camera, etc — that is FBX.
I know that doesn’t directly answer your intended question but I am hoping understanding the formats better will aid you in deciding what format to use, when.
Matt - Autodesk
Fusion
