convert 3d solid in 3d face

[pelton]

It's my first message on the forum. I hope I'm in the right section.
I come to the point.
I once have a pavilion made with 3d solid, I would like to convert it into 3d faces as I have to insert the file into a calculation program. I tried to explode but I get out of the regions.
How can I do that?

 

[GP.]

Try meshsmooth to turn regions into mesh and then explode, you should find some 3dfaces.