not sure why - but  external geometry has always been a requirement for most poser stores. my guess is dates back to the p4 days when memory was tight more than external useage.

usually objs contained within runtimes don't have a coressponding mtl file either, which some apps like when importing stuff.

So usually when exporting to other apps the trick is export the whole scene from poser, copy all the required texures from your runtime into the same folder as that exported  obj/mtl file. Then import that combo into your desired app.

Which I belive is related to the way paths are written to the mtl file. not a poser flaw more how the mtl is a little extra.

 

Pinky - you left the lens cap of your mind on again.