First I created a low and high poly model. I then set the coordinates to (0,0,0) so they were on top of each other and exported them separately as a .fbx file. Then imported the low poly cube into substance painter. I went into the texture set setting and made the high poly cube the bake map. This made the low poly cube look high poly but without all the polygons. Finally I added a smart material so the light reflects differently on the surface.
Daniel Porter 