First of all, i have no idea if this topic is in the right section, secondly, hello 
I have a weird problem with the DM of my training dummy model, after i generate the DM, there is no filling/inside, i’ve read [THIS][1] topic but i have no idea what to do, the model seems to be in good condition.
I’ve made it in Blender.
And yes, it has to be Low Poly, that’ll be the style of my game.
Any clues?