Exploding Polyline Question

[Anonymous]

I was wondering if there is a way to explode a polyline, but have it remain a polyline? When I explode a polyline containing many angles, the polylines all turn into regular lines...is there a solution to this?

Thanks

[tcorey]

It's sounds like you're saying you want to explode a polyline but you don't want the polyline exploded. That makes my head spin.  😉

What property are you trying to eliminate from the original polyline? Maybe there is a solution other than using EXPLODE.

[Anonymous]

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@tcorey wrote:

It's sounds like you're saying you want to explode a polyline but you don't want the polyline exploded. That makes my head spin.  😉

What property are you trying to eliminate from the original polyline? Maybe there is a solution other than using EXPLODE.

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Haha, it is a bit confusing, especially with how I tried to explain it. Here is a long (probably confusing) explanation/question:

When I explode a single long polyline containing many PIs, tangents, etc., they all turn into smaller broken-apart regular lines. I want all of the broken-apart regular lines to remain as broken-apart polylines instead. I don't want to select them all again and turn them into individual polylines, it would take some time in my case.

Shorter easier to understand question:

Why does a polyline turn into a regular line when it is exploded?

I want to keep the 'elevation' property on the polylines that are exploded. A regular line doesn't have an 'elevation' property.

[tcorey]

After exploding the polyline, use PEDIT command, Multiple option, select all the newly created lines and arcs. AutoCAD will ask if you want to turn them into polylines. Say yes and then Enter until back at the command prompt. You will now have individual Polylines. 

Just FYI, when a polyline explodes down to lines and arcs, the objects won’t have an elevation property, but their points will have z values. 

[Jeff_M]

Here's a quick little lisp that will automate the task for you:

(defun c:pexplode(/ ss idx ent)
  (if (setq ss (ssget '((0 . "LWPOLYLINE"))))
    (progn
      (setq idx -1)
      (while (setq ent (ssname ss (setq idx (1+ idx))))
	(command ".explode" ent)
	(command "pedit" "m" "p" "" "y" "")
	)
      )
    )
  (princ)
  )

[Anonymous]

If you are exploding a 2d polyline, the vertices didn't have elevation information to start with (a polyline can only exist at one elevation).  Exploding a 3d polyline and the line segments will retain their elevation data.

[tcorey]

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@Anonymous wrote:

If you are exploding a 2d polyline, the vertices didn't have elevation information to start with 

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Not to be overly pedantic about it, but that's not really true. In a 2D Polyline or LWPolyline, each vertex has the same elevation, but they do have elevations. Use LIST command on any polyline and you will see that each vertex has x, y and z. 

[codee]

1) Explode the polyline

2) activate "PEDIT"

3) select "multiple"

4) Select all of the exploded normal lines and arcs

5) "convert" to polylines?" YES

[Anonymous]

I feel like that's splitting hairs....  does each pline vertex have an elevation? Or does only the pline itself have an elevation?  Both are technically correct and if you start questioning what "has" the elevation you get some sort of philosophical paradox.  

Point is, exploding a 2d pline will result in all segments having the same elevation.

[tcorey]

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@Anonymous wrote:

I feel like that's splitting hairs.... 

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No doubt about it. That's why I said I'm probably being overly pedantic, but...

[AllenJessup]

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@Anonymous wrote:

does each pline vertex have an elevation? Or does only the pline itself have an elevation? 

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The old 2D Polylines carried an elevation for each vertex. The newer LWPolylines have one elevation for the whole entity. There are additional differences.

[Anonymous]

That is GENIUS! How do I make it so that my CAD remembers your lisp, so I do not have to constantly input that into my CAD everyday. 

My Polylines used to explode automatically and still be polylines but for some reason they turn into lines... I do not like to use lines because then you cannot put a Global Width to it anymore. Besides your lisp, I couldn't find any other way to get my explode function back to the way it used to be. 

[AllenJessup]

Probably the easiest way would be to drag it into the Startup Suite. Browse in the upper pane to the location you keep the Lisps. Then drag from the upper pane to the Startup Suite.

There are other way such as loading it from the acaddoc.lsp file. See HERE