After much searching for a 3DClip command and giving it up, it finally showed up. I just typed "V" for Views and a dialog with options for preset and customized views popped up, and even a cipping option! Pretty well hidden! This is not reference cipping, but 3D object clipping. I found this because I inserted a file with saved 3DClipped views. Actually, when I chose front clipping On, and set shading on Hidden mode, my 3D model's plan section appeared just as I had it. After some fumbling, the front clipping plane's position was lost, so I tried to reset it changing the values for "Front plane" in the dialog, with no result.

I'm posting a screen capture of this dialog box. Note the option for "Perspective". It actually works just fine.