Thank you for your informative answer, Michael. I had tried doing separate/join, but I had selected everything using a selection box. I guess I have to more carefully choose only the surfaces for the solid.

Thanks again!

Thank you,, Frenchy. That's a great way to do it. I'll be sure to try your technique. Your help is much appreciated!

Hi tofuji, you're welcome! yes for this case here there are various internal surfaces that you don't want to be part of the final object but a window select will get those too.

- Michael

If you running windows 10 use 3d Builder ( some builds have dropped it but you can still download for free through Microsoft Store) it has auto repair on opening STL and OBJ files - it was built on NETFABB which Autodesk bought - Microsoft then pealed some of the repair out tools out of NETFABB and built into the 3d Builder I use it all the time as quick cleanup tool it will heal most files with problems.

Bonjour Pilou, tested simlab quickly looks good..curious to know what software you (or Wayne) use for the giff animations? Stefano.

For the Gif I use this free very small & simple but very cool GifCam
http://blog.bahraniapps.com/gifcam/

SimLab Composer Lite is Free (Maxi 1920 * 1040)
Sufficient for Still images for Internet! Can be used commercially!
https://www.simlab-soft.com/3d-products/simlab-composer-lite.aspx

...seems BreakDown for the moment !

but you can take a look to my French one! ;)

https://simlabfr.weebly.com/light.html

Else a very cool one (even free if you have donwloaded previous free version 2019)
is TwinMotion 2020
Interface truely easy and remarquable possibilies!
Even new simple animations (Translation & rotation) of objects!

Hi Pilou, as long as simlab breakdown and not you...
Je suis très jolie. I heard this new kid on the block is worth a check out https://bellarender.com/ 'physics modelling approach'. Anyway also site version in French. Rendering for me or speaking French is a bit later...Let me know what you think if you have time to test.
Salut!

I don't remember this one! :)

Seems very capable and their site is very classious!

Seems there is also a free version (1280×720 with little watermark )
Works as Standalone and...
.. seems there is an SKetchUp integration :) (Rhino - Maya)
I will test that! :)

Edit : Ok That works fine with the free SketchUp 2017 Make!

For the Bella Standalone...that works also but I'm not gifted...i must miss something!
All is imported but I success only to render a "Sphere"who has nothing to do with the model above! :) ( Export / Import DAE from SketchUp )

I have found :) I must make a big Zoom out...Scale is not automatic or maybe not by default! :)

And apply materials is not evident: there a little problem of Path so for the moment only one texture! :)
That is not very clear as process!

Thank you, Alex. I'll be sure to try that next time.

About the Stand Alone BellaRender
with the files OBJ you must put all in the same level folder!!!
obj, mlt, jpg
Alas this tricks works not for the DAE (+ PNG)