Cannot join lines into polyline (3D polygon)

[anukeen]

Hello and thanks in advance,

I am trying to Join four connected lines into a polyline, but it will not work!  My operation has been:

PEDIT/PE -> M -> select all lines -> Y -> J -> fuzz (up to 0.1!) -> enter

No polyline!

I have full AutoCAD 2013 for MAC (not LT).  I'm working in 3D, as you can see in the drawing.

If the lines are not coplanar, why does this happen? In AutoCAD for Mac, how can fix this?

Thanks!

A

[maxim_k · Accepted solution]

Welcome to the Autodesk Forums!

Hi,

There are duplicate lines (one line above another line) in the drawing you provided.

If you will delete duplicates, you will be able to join lines with PEDIT -> M option. See attached DWG - I copied all lines, removed duplicates with OVERKILL command and joined lines to single polyline with PEDIT -> M -> J

Maxim

[anukeen]

Thank you.  But actually, I am trying to make each of the parallelograms a pline.  The 6-sided base was just left to show the UCS.

Beyond just these parallelograms, I'm trying to figure out why this happens so often.  What are possible reasons?  Duplicate lines? Lines not touching?  Not coplanar?

Thanks!

[maxim_k]

Lines are not coplanar in each of 4 lines set.

You can check this with ID command with ENDpoint object snap.

In each 4-lines set upper right corner doesn't lie in the same plane as other corners (see attached DWG)

Maxim

[anukeen]

I don't understand why points would be off in the .000001 decimal place.  Why does this keep happening when I always use my snaps.  I thought AutoCAD was supposed to be precise!

That being said, what is the best solution in AutoCAD for Mac? How do I bring these lines into the same plane?

Thank you, maxim!

[maxim_k · Accepted solution]

AutoCAD has precision up to 16 decimal places, and AutoCAD for Mac too, so it looks like your fault during creating lines.
You can flatten lines by setting UCS to one of the lines you want to use as "base" and then editing Z value of end points of the other lines that appears in the same plane as your "base" line (you can do this via Properties palette)

Maxim

[anukeen]

It gives me comfort that I'm making the mistakes, not AutoCAD 🙂

I attempted your solution, but...

The "Properties Inspector" gives editable World UCS coordinates.  When I based the UCS on the plane I want to flatten, it only changes the Delta coordinates.  Delta coordinates are of course not editable.  What am I missing?

[maxim_k]

Yes, you are right. It is impossible to use Properties palette in such case (that was my fault)
And it appears there is no simple way to flatten lines to UCS in AC for Mac. So my advice is to re-draw polyline above existing lines: just setup UCS you need, than start polyline at zero elevation and use object snap to endpoints of existing lines - polyline will be created flattened, because polyline is 2D flat object.
Another way is to copy lines to new drawing after you setup UCS, than use Properties palette in this new drawing to change Z coordinates, than return back flattened lines to your first drawing using copy - paste procedure.

Maxim

[anukeen]

Ha! I guess the lesson is just to draw it correctly from the beginning.

Thank you.