AutoLISP: vla-offset and layers

[lynx_20]

Our CNC department requested a co-worker include an offset to the part profile and have it on a different layer [rough_pass]. Our only issue is that it involves hundreds of hexagons. This phase they are tessellated so doing a few & arraying will work but the next 2 phases they are pseudo-random.

I found a great lisp in one of the forums that will allow you to select multiple polylines & offset in or out a given distance. The problem is that it uses vla-offset which ignores layers. Normally I would try and hack in something that would solve the issue but with my current project load & my lack of skill using 'vla-' stuff - I do not have the time.

Below is a clip of the critical section. I have also attached the entire file.

(progn ; level2 then -- proceed
            (setq
              obj (vlax-ename->vla-object ent)
              oarea (vla-get-Area obj)
            ); setq
            (if ; level3
              (not ; Offset succeeded [returns T if so, because:]
                (vl-catch-all-error-p ; returns T for error if inward but too small
                  (vl-catch-all-apply 'vla-offset (list obj *OIOdist))
                ); -error-p
              ); not
              (if ; level4 is level3 then -- check comparative areas:
                ((if (= subpr "In") > <) (vla-get-Area (vlax-ename->vla-object (entlast))) oarea)
                (progn ; level4 then -- went wrong way
                  (entdel (entlast))
                  (if ; level5 -- go the other way [if possible]
                    (vl-catch-all-error-p ; returns T for error if inward but too small
                      (vl-catch-all-apply 'vla-offset (list obj (- *OIOdist)))
                    ); -error-p
                    (setq nogo (1+ nogo)); then -- add to count of too-small [no else]
                  ); if level5
                ); progn
              ); if level4 [went wrong way -- no else; do nothing if it went right way]
              (if (= subpr "Out") (vla-offset obj (- *OIOdist)) (setq nogo (1+ nogo)))
                ; level3 else -- too small for inward; go other way only if OffOut
                ; if OffIn, add to count of too-small
            ); if level3 [Offset succeeded]
          ); progn [then]

For now 'hard coding' the layer name & assume the layer exists will work. If this comes up again I can pretty up a user interface. Any help would be greatly appreciated.

[Tom Beauford]

See https://www.cadtutor.net/forum/topic...yer-need-help/