Converting 3d surface to 3d solids

[pnoy2its176911]

Is there a way to convert 3d surface objects to 3d solids object. I created a revolve object and it turns to surface and I would like to union it to a extruded object but does'nt allow me. any help will be appreciated. Thank you.

[jaberwok]

Google "closed mesh to solid".
There are several possibilities shown.

M2S.lsp (google that too) will convert open mesh objects.

[cjehly]

Is there a way to convert 3d surface objects to 3d solids object. I created a revolve object and it turns to surface and I would like to union it to a extruded object but does'nt allow me. any help will be appreciated. Thank you.

You revolved a series of lines most likely, or an unclosed polyline. Convert your lines to a polyline (check out BOUNDARY - it is a great command for walls) and make sure its closed, and you will end up with a solid after you REVOLVE.