Where did these vertices on my offset ellipse come from? I want them gone now.

[JackOfAllTrades]

I use vanilla AutoCAD 2012 to do strictly 2D drafting and designing.  I'm not a dedicated drafter by trade, but I interview them all the time at our company.  Today I interviewed one who wanted to show me some of his 3D work, so we pulled it up on my computer for a bit, and I let him show it to me.  I saved his drawing to my computer, closed Autocad completely, then later opened it back up to work on my drawings.

Anyways, I draw an ellipse.  It's completely normal.  I then offset that ellipse inward as I have done hundreds of times before.  It looks fine, but then I select it, and that's when I notice it's completely different.  It does not have four quadrant grips and a center one like the ellipse from which I offset it.  Instead a brown polygon approximation of this ellipse with dozens of "vertices" appears on top of my green offset ellipse, which also appears to be selected.  the vertices have the options to Stretch, Add, Refine, or Remove them.  The parent ellipse is completely normal.

I have never had this happen before so I figure he either changed some setting or his drawing did when he loaded it up in my AutoCAD.  It's quite likely he drew it in one of the AutoCAD 3D variants according to his resume or even in CADWorx.  I need to know how to get rid of this and back to my normal settings.  I have no idea whether this vertex grid will appear other places as well.  It's unusable for my purposes.  Circles seem to offset normally.

Any ideas on what settings I need to change to get back to normal?  Thank you.

[Patchy]

F1, look into PELLIPSE variable.

[artc2]

The offset of an actual ellipse entity won't be an ellipse it will be a closed spline (with lots of grip points).  But, if the ellipse is really a closed polyline approximation and not an actual ellipse entity, then the offset will be another polyline approximation, so it would appear to have the same number of grips as the original.

[dmfrazier]

I'm guessing that the other responders have solved your mystery, but I just thought I would throw in an extra 2 cents (for free).

It's very unlikely (though not impossible) that opening someone else's DWG will change any of your AutoCAD settings that are not stored in the DWG file itself.  Saving a copy of the file would still make no changes to your non-DWG-based settings.  Since the PELLIPSE variable is stored in DWG files (not as an overall system "preference"), you would have to make sure it is set the way you want it in each drawing.

[Kent1Cooper · Accepted solution]

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@JackOfAllTrades wrote:

... I draw an ellipse.  It's completely normal.  I then offset that ellipse inward as I have done hundreds of times before.  It looks fine, but then I select it, and that's when I notice it's completely different.  It does not have four quadrant grips and a center one like the ellipse from which I offset it.  Instead a brown polygon approximation of this ellipse with dozens of "vertices" appears on top of my green offset ellipse....

I have never had this happen before....

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I don't think it can be true that an Offset [true] Ellipse has not behaved in this way before, but as others have mentioned, a Polyline-approximation Ellipse [drawn in versions of AutoCAD prior to the introduction of the true Ellipse, or drawn with the PELLIPSE System Variable set to 1] would be similar to the one it was Offset from.  But neither of those would have center and quadrant grips, though at least they would have fewer than what you're seeing.  Because of the nature of the shape of true Ellipses of different axis ratios, an Offset Ellipse that is truly an Ellipse will not be the same distance from its original everywhere, which is why AutoCAD draws a Spline instead, since that can be [within some tolerance] the same distance away all the way around.

If you want to Offset an Ellipse with the result being a true Ellipse, whose distance from the original is the specified Offset distance at the quadrant points but will stray somewhat from that elsewhere, you can use this routine, OffsetEllipse.lsp with its OFEL command.  [If you use the Through option rather than specifying a distance, the result will go Through the point you picked to a small tolerance, and the distances from the original at the quadrant points will be the same as each other, though slightly different from the distance at the Through pick point if that wasn't at a quadrant.]  If you use that and regular Offset on the same Ellipse, you'll see the difference in the shape of the results.

[JDMather]

...if you need a true ellipse offset - the Autodesk Inventor product lets you choose between true ellipse and constant distance offset results.

(see attached image)

[JackOfAllTrades]

Thank you, everyone for your replies.  To put it simply, you're all right.

It's been a while since I've drawn much of anything, and I'm relatively new to all the additions of AutoCAD 2012.  When I saw that brown polygon, I got all freaked out.  Lots of stress yesterday.  I have since gone back and looked at some of my drawings from a few years ago, and now I remember that indeed the offset ellipses did exactly the same thing back then with the many vertices.

I changed PELLIPSE back and forth, and it didn't change the behavior of the offset as you all suspected it wouldn't.

I know I said it's unusable, but, of course, that's not true.  I'll make things work, even if it's slightly more complicated than having the imaginary thing I thought existed.  Thank you all again.

[JackOfAllTrades]

It's good to know that opening someone else's CAD file wouldn't automatically change any of my settings.  I also thought that maybe he might have changed something himself as he was showing me his model.  Clearly, I was wrong on both accounts.  Thanks for the clarification.

[JackOfAllTrades]

You're entirely right about everything, and I learned quite a lot from your post.

I will look into using that routine if I really need a true ellipse.  The spline is actually fine for my purposes, but you never know.  Thanks for the explanations and tip.