I've had a nightmare couple of days trying to use a particular model in my race demo game. One of the last real coding tasks I had to do.
I wanted to use it for a number of reasons, not least of which is its a very cool model. which also comes with a normal and specular map.
But try as I might I could not get the damn thing to load, There were a range of small issue that stopped it.
The Jpg files didn't load correctly for 1, the obj references a texture on the makers PC, the 1st shape was a convex hull with no texture, there is a transparent window section, there's multiple detail shapes that don't need to be rendered (which is useful to explain occlusion)
Somewhere along the line, the jpgs and or the texture coords got mangled.. though they worked fine in other model viewers, TinyObjloader wasn't having it.
But after 3 days of exporting, in different packages, reducing the vertex counts and a range of other things.. I got it to work.
Behold, a 20,000 face model, Though I don't have a suitable shader for the windscreen at the moment