@mark
Thank's so much for your clear and detailed answer, all seems to me obvious now !
I made some tests on stage with the 3D Player to display a .3ds file on the real object, it works fine but in my case it takes to much time to setup (constraints from the company...).
I finally used the 3D Quad Distort actor, but 3D actors are very powerful and I hope to use them soon.
Thank's again, best wishes.
Clement
For those who are interested by the topic, an example of use of the 3D Light Orientation actor
d7cbdf-3d-light-orientation.jpg