BTW, smoothing information (hard or soft edges) can be retained by the OBJ file format itself. Some packages, such as 3dsmax, have specific settings in the export dialogue for OBJ which allow you to save smoothing groups. This is saved in combination with explicit vertex normals. If you look at the OBJ in a text editor, you might see "Vn" in the text, which stands for vertex normals. If you see text blocks starting with "S", these would be smoothing information. Now if the smoothing information is correctly interpreted by a software's OBJ importer is another story, but OBJ can handle them. Here's a screenshot of the OBJ export dialogue in 3dsmax, for example.

So it all depends on the software's import/export features of whichever file format you choose. Many packages only use some of the features OBJ is capable of handling. This is why FBX became the preferred file format for some file exchanges. The import/export plugins for FBX tend to all support the same things (usually), but I did notice Blender's FBX features leave something to be desired when it comes to rigging and animation.

______________________________________

My Store
My Free Models
My Video Tutorials
My CG Animations
Instagram: @luxxeon3d
Facebook: https://www.facebook.com/luxxeon