Sometimes when exporting modells using different exporters, they sometime appear inverted.
for an example take a look at the video in my previous post.
It turns out, that all the normals were inverted, so in order to get around this problem, the normals of the mesh must be flipped in 3ds Max (or any 3d package) before they are exported.
To do this in max is very simple.
- right click your object > convert to Editable Mesh
- Select your entire model so that all faces are RED.
- in the modifiers panel select Normal, then in the parameters roll out, make sure Flip Normals box is ticked.
- if you would like to see your Normal lines, go back to your Editable Mesh and tick the box “show Normals” in the selection roll out
And thats it 
