;;;Convert A Selection Set Of 3DFaces To A PFace Mesh
  (defun fa2pf (ss / slen i ed en ef vlist vlen tlist)
  (and (/= (type ss) 'PICKSET)
       (princ "*** Invalid Parameter To FA2PF *** ")
       (exit))
  (princ "\nDetermining Vertex Data\n")
  (setq slen (sslength ss)
           i 0)
  (repeat slen
      (setq en (ssname ss i)
            ed (entget en)
             i (1+ i))
       (and (/= (cdr (assoc 0 ed)) "3DFACE")
            (princ "\n*** 3DFACES Only *** ")
            (exit))
       (foreach g '(10 11 12 13)
              (if (not (member (cdr (assoc g ed)) vlist))
                  (setq vlist (cons (cdr (assoc g ed)) vlist))))
       (princ (strcat "\r" (rtos (/ (* 100 i) slen) 2 0) "% ")))
  (princ "\nDetermining Face Data\n")
  (setq vlen (length vlist))
  (entmake (list (cons 0 "POLYLINE")
                 (cons 10 (list 0 0 0))
                 (cons 66 1)
                 (cons 70 64)
                 (cons 71 vlen)
                 (cons 72 slen)
                 (cons 73 0)(cons 74 0)(cons 75 0)
                 (cons 210 (list 0 0 1))))
  (foreach v vlist
     (entmake (list (cons 0 "VERTEX")
                    (cons 10 (trans v 1 0))
                    (cons 70 192)
                    (cons 71 0)(cons 72 0)(cons 73 0)(cons 74 0))))
  (setq i 0)
  (repeat slen
    (setq en (ssname ss i)
          ed (entget en)
          ef (cdr (assoc 70 ed))
           i (1+ i)
       tlist nil)
    (foreach c '(1 2 3 4)
      (setq tlist (cons
        (cons (+ 70 c)
              (* (if (= (logand ef (expt 2 (1- c))) (expt 2 (1- c))) -1 1)
                 (1+ (- vlen (length (member (cdr (assoc (+ 9 c) ed)) vlist))))))
            tlist)))
    (entmake (list (cons 0 "VERTEX")
                   (assoc 8 ed)
                   (cons 10 (last vlist))
                   (if (assoc 62 ed)
                       (assoc 62 ed)
                       (cons 62 256))
                   (cons 70 128)
                   (nth 0 tlist)
                   (nth 1 tlist)
                   (nth 2 tlist)
                   (nth 3 tlist)))
     (princ (strcat "\r" (rtos (/ (* 100 i) slen) 2 0) "% ")))
  (entmake (list (cons 0 "SEQEND")))
  (command "_.ERASE" ss "")
  (redraw (entlast)))


;************ Main Program ***************************************
(defun c:makemesh (/ ss)
  (while (or (not ss)
             (< (sslength ss) 2))
         (princ "\nSelect 3DFACEs To Join:   ")
         (setq ss (ssget '((0 . "3DFACE"))))    )
  (fa2pf ss)
  (prin1))