It will be very usefull to have a sketchup viewer plugin inside opus directory; not necesarelly a 3d viewer function, just a 2d.
There is a dll file inside the program files of the mentioned software, called thumbsup.dll that allow view thumbnails inside the windows explorer, so I think it will helps for the development of the plugin. I think so.
I´m not a programer, and I don't know if it is easy. But every intent will be great.
Thanks a lot. 
If you turn on shell image extraction in Opus's thumbnails mode preferences then you should see thumbnails for them.
(Won't affect the viewer, though. I suppose a generic viewer could be made which uses the same API to try to extract a large "thumbnail". Not sure how well that would work since I bet a lot of thumbnailers expect to be asked for fairly small images, but it might work with some things.)
OK. Mr. Leo
I will tray that option, and I'll tell you later.
Thanks and have a Good Weekend.
Hi Leo, about enabling the option called shell image extraction inside preferences, yes it works, and also for 3dmax thumbnails that I haven't seen before, so it helps when I search for my 3d models, but not for the wiewer, anyways that's a minor detail. Thanks a lot.