if you add more object3Ds to your world, then you will have more polys to draw. the Config.maxPolysVisible just set the amount of plys that can be seen on the world. Each Object3D is draw with triangles that are poligons after all. so, how do you draw your cube? is imported from a 3ds file. then you should check, how many polys does your cube have. And dont forget that Config.maxPolysVisible have to be called before creating the world.