CAD Tip 1025: Polylines are your friends

Good works are links that form a chain of love.
–Mother Teresa

Polylines are your friends.  If you make more use of them, and learn more of the tricks and features of using them, you will, I believe, come to appreciate their many advantages.

One highly capable CAD designer who I worked with showed me this.  He would fill the world of a CAD drawing with polylines.  At first I wondered why he spent his time doing it.  Later I gradually came to understand the benefits.

Batman symbol drawn using the Polyline tool and the Second Point option

Polyline benefits include:

  1. Can be closed or open.
  2. Foolproof boundaries for hatch objects (no leaks!) when closed.
  3. Can be associated with a hatch object for easy adjustments of the hatch later.
  4. Save-able, editable enclosures for area takeoffs.
  5. Easy to go back later and see the precise area boundary to verify accuracy of a takeoff.
  6. Easy to select entire polyline for any editing needed (fewer objects to find and click on).
  7. Easy to stretch and re-size with no trimming.
  8. Easy to “send to back” or front of the draw order.
  9. Width of polyline (as it appears graphically) can be set using Global Width variable.
  10. Can add or delete vertices with little time/effort cost.
  11. Can combine straight lines and arcs in a polyline.
  12. Arcs meet straight lines (if the arc follows the straight line) in perfect tangential relationships by default.

    Polyline with arcs and straight lines in tangential relationship

  13. Arcs meet arcs in perfect tangential relationships.
  14. If desired, an arc can meet a straight line in a non-tangential relationship (using the Second Point option).
  15. Great tool for measuring the length of a path (or a pipe, wire, etc.) when open.
  16. Polyline can serve as a quick and easy substitute for a simple block.
  17. When acting as a substitute for a block, a polyline has multiple insert points for easy copying, moving, etc.
  18. Can be 2D or 3D.
  19. The Undo function works inside of the polyline creating tool (PL).
  20. Simple lines and arcs can be transformed into polylines using the Polyline Edit (PE) tool.

I could go on and on.

Remember also that a rectangle created using the Draw>Rectangle tool is a particular shape of polyline, having the above advantages.  It’s a good idea to use rectangles, whenever possible, to create a rectangle, instead of using individual lines.

Well, until Gotham needs me again, that’s it for now.

Keep on CADDing!  🙂

Mark