Problem Extruding a Polyline

[lisaz0224]

Hi guys

 

For some reason I can't extrude this polyline. I'd drawn it as a bunch of splines at first, but then I found out that they weren't joined together. I traced over all the individual splines with one spline, and then deleted everything underneath. It still won't extrude. Can anyone tell me why? I tried a bunch of things--pedit, joining, etc. Nothing.

When I click 'extrude,' the command thing says 'select objects to extrude or [MOde]:'. I clicked my spline and it highlighted, and then I hit enter. The message doesn't change.

 

Any suggestions?

[tzframpton]

First, make sure the polyline is closed. Or instead, use the PRESSPULL command. If you want to still try with EXTRUDE, then use the REGION command first, to create a plane region - then try the extrude. Hope this helps.

 

-Tannar

[lisaz0224]

Thanks for replying!

 

Something is still off, though. It's definitely closed--when I used pedit, the only option was 'open.' just to make sure, I used the pedit function to open it, and then close it again. I also tried press-pulling. Same problem; the command said to select objects, I did, the command didn't change. Just to make sure, I extruded a random 2d polygon I made, and it worked fine. Then I presspulled one. Same thing, it worked.

I know this is a strange question, and I don't think it's the factor, but is it maybe because the shape is too complex? it's not that bad--it's one of the handles of a chandelier, but when I use certain commands on it my computer freezes up. Right now, there's a spinning beach ball on my screen.

What do you think? What do I do?

[SuperCAD]

With PRESSPULL, the lines don't have to be connected like a polyline. In fact, the shape can (usually) be made from a bunch of different types of objects (lines, polylines, arcs, splines, etc.) The end points don't even have to be touching, the boundary does need to be closed (i.e. as long as the object intersects with another, you should be good).

 

That said, yes the shapes can become too complex for AutoCAN'T to extrude. This program is a Jack of all trades and a master of none. Complex solid geometry is not a strong function of AutoCAN'T, but it is getting better.

 

Can you post the file here and we'll mess around with it to see what will work?

[JD Mather]

I also tried press-pulling. ....the command said to select objects, I did, the command didn't change. ... maybe because the shape is too complex?

 

No, the presspull command prompts to select object OR area. Because you selected object and it didn't work - I'm betting a self-intersecting curve.

Attach your dwg file here and end all doubt. (For the life of me, I can't figure out why so many ask questions without providing enough information. At least a screen capture. And if a picture is worth a thousand typed words, the actual geometry might be worth a thousand pictures. Attach the dwg here.)

[ReMark]

"For the life of me, I can't figure out why so many ask questions without providing enough information."

 

Because we like playing 20 Questions?

 

+1 on the suggestion to attach a copy of the drawing in question.

Edited January 26, 2014 by ReMark

[tzframpton]

This program is a Jack of all trades and a master of none.

Classic!!

[ReMark]

I wouldn't necessarily agree. Given enough time and effort the user can shape the program to be exactly what he or she wants it to be. It's all about the customization. You too could become a Jedi-AutoCAD-Master.

[tzframpton]

I wouldn't necessarily agree.

Have you ever had extensive experience with another trade-specific CAD application? I have, and I totally agree with SuperCAD's opinion. However, AutoCAD is the best "general" CAD application, hand's down.

[ReMark]

You denigrate the hard work some users have put into making their version of AutoCAD uniquely trade-specific.

[tzframpton]

You denigrate the hard work some users have put into making their version of AutoCAD uniquely trade-specific.

Not at all. David Bethel and myself once had a discussion on here regarding him and his company transitioning to Revit, and in the end it wasn't a good idea and I agreed with him because of all the time and investment he's put into making AutoCAD fully parametric to fit their needs - something Revit does right out of the box. I promote people to use whatever program best suits their needs, and continue using it regardless of new waves of CAD software as long as it is still a financially good decision.

 

With SuperCAD's comment, this is the way I see it: You can use a hammer (AutoCAD), which is a tool that can be used for general purposes, to hammer nails into wood. Or, you can use a pneumatic nail gun (Inventor/Revit), which can only drive nails. It's specific, and does the "one thing" very well and very fast, where as a hammer can be used for many general purposes cannot compete with the nail gun in that one thing it does well. It just depends on one's personal needs in the end.

[lisaz0224]

Yeah, I figured I should've attached a screenshot from the start, but the upload manager thing wasn't working for me :/ sorry.

But I think you're right that it's a polyline that overlaps itself; that might be the problem.

[ReMark]

I could see where you might experience a problem near the bottom of your profile where it rolls back on itself like JDM mentioned.

[JD Mather]

... a polyline that overlaps itself; that might be the problem.

 

I can see 4 areas that don't make logical sense to me.

[Patrick Hughes]

I can see 4 areas that don't make logical sense to me.

 

 

Yep, each of those curly q's is a no-go.

[SuperCAD]

I agree with JD and Patrick. The splines/arcs that are inside the boundary that you're trying to extrude are the problem. I worked on a file that was supposed to mimic hand-carved wood (which is the impression that I get from this) that we cut on our CNC and it came out OK, so I might have a few pointers for you but it won't look as pretty, or be as easy, as you're probably hoping for.

[a3dtot]

Extruding a pline from a spline is a hit and miss, personally I never use splines unless I modify a pline and that can still cause problems. I have seen in responses above a couple of things to consider. 1st "Can a spline/pline be too complicated" answer Yes. Now my wording may be incorrect but after 25 years doing 3D on autocad I ask for some leeway. A spline is not really an object or at least it doesn't seem to act as one. I receive a lot of ship and barge models and they seem to be huge fans of splines even though a properly made pline does the job better and is more workable and when you extrude a spline you do not get solids but regions. This is again why I say it is not a real object. 2nd one of the problems with a closed spline is the high likely hood that it will have a self intersecting curve which will not allow the functions you are trying. Solution: Draw a pline over the top of your spline with as many points as you would like when finished close the pline and extrude. Guarantied to work, unless you make a self intersecting curve.

To those who speak of other programs as a solution. In all these years not one has been able to do what plain old autocad can do in the right hands and with the unlimited customization. AutoCAD Rules.

[JD Mather]

A spline is not really an object or at least it doesn't seem to act as one.

Works like a "real object" on my machine.

 

...when you extrude a spline you do not get solids...

I get solids on my machine.

 

To those who speak of other programs as a solution. In all these years not one has been able to do what plain old autocad....

 

I don't even know what this means?