Bonjour philippe - unfortunately it is somewhat tough to do this, since SketchUp files only contain polygons and not NURBS surfaces like MoI is designed to use.

So for example if you have something that looks similar to a sphere in a SketchUp file, it is not really a sphere but instead a whole bunch of little planar facets with their edges hidden to make it look as if it were smooth.

This kind of fragmented geometry does not work very well with MoI - MoI is designed to work on a sphere as one large smooth surface patch that actually defines an exact sphere and not a fragmented approximation.

So it is not in general a great fit for MoI to bring in SketchUp data, in many cases the data is just not the type of data that MoI is meant to work on.

However, you can export smooth surfaces from MoI into SketchUp format. When you do this MoI will break its smooth surfaces down into facets and write those facets to the SKP file.

But unfortunately it is very difficult to do the reverse process automatically - it's sort of like how if you start with apples you can make applesauce by smashing them up. However, if you start with applesauce it is not easy to try and make apples back from that.


I think in the future I should be able to add some mechanism to bring in polygon data to use just as a visual and snapping reference rather than as actual geometry to work with (to trim and boolean, etc...). But I don't expect to have this ready for v2 though, possibly for v3.


In the meantime, you may want to take a look at the OBJ to 3DM wireframe converter program which is available here:
http://moi3d.com/wiki/Resources#Obj23dmWireframe_converter

If you can export your polygon data to an .obj file, you can run that converter program on it to extract the edges of the polygon data to a .3dm file as line segments and then load that into MoI to use as a reference. That may be useful for getting some kind of reference set up in the current version.

- Michael