With ObjReader, you can load 3D models at runtime, from local files or the web. Just pass in a file name (or a string containing the .obj file), and automatically get back one or more GameObjects.
Works with most .obj files from a variety of sources, and has .mtl file support for materials and textures. Includes various options such as generate tangents, position/rotate/scale, and combine groups into a single mesh or generate one mesh per group, using submeshes or not. Plus it's fast...a 4MB .obj file will typically generate a mesh in less than 0.5 second, depending on CPU speed.
Includes source code, and works on all platforms. (Loading from local files is not supported in WebGL.) 32-bit mesh index buffer support is included for Unity 2017.3 and later. See the forum thread for news and information.