Importing AutoCad drawings into SketchUp

[andrewm]

I had hoped to be able to import simple 2D AutoCad drawings into Google SketchUp and use the imported shapes in the same manner as a SketchUp shape, i.e. be able to extrude it, edit it etc. However after a few simple experiments all have have ended up with is a drawing that I can move around but not do anything else with. Can any of the SU experts out there tell me if I am obviously doing something wrong or is what I am attempting not possible.

Andrew

 

[Steve Maskery]

Andrew
Send me your ACAD drawing, please.
steve at stevemaskery dot co dot uk

Cheers

 

[SketchUp Guru]

Andrew, Steve will get you set up I'd like to know something. If you import the file into GSU and then select it, do you get a bounding box around it? If you right click on it do you get the option to Edit group?

If the answer to those questions is yes, you can either edit the group or explode it and then work with it.

 

[andrewm]

Dave, Yes, I can explode it but all that leaves me with is a series of lines which I cannot use to push/pull etc.

Steve, Thanks, I will send it through to you this evening when I get home.

Andrew

 

[Steve Maskery]

Andrew
You need a surface in order to push/pull, not just the outline. If it is closed, but no surface shows, either use the Make Face.rb script or delete one of the lines and draw it in again. If the outline is planar and closed SU should automatically create the surface, which you will be able to see. Then you can P/P.

Anyway, if that doesn't work, send me the file and I'll have a look at it for you.

Cheers
Steve

 

[SketchUp Guru]

As Steve says, you need to close up to create faces. You don't actually have to delete lines and redraw them though. Just trace over them. While you're working on it, check a couple of other things with the model. triple click on one line and check to see if all the "attached" lines are selected too. If there are lines that should be selected but aren't, check the intersection carefully. Frequently CAD drawings are pretty sloppy at corners with either open ones--lines not actually touching--or overlapping lines where the endpoints aren't joined. To fix the former just extend one line to meet the other or extend both as required. To fix the overlap problem zoom in close and trace a line segment to the desired intersection. Then you should be able to delete the extension.

I guess you'd figure this out also by tracing lines to close faces. If the faces don't appear after tracing it is possible that you have one or both of those problems.

The other thing that happens sometimes is that the CAD drawing isn't really flat. Some line segements import as a little higher than the others. That's a lack of copanarity or coplanarism. (I just made those words up. ) There's a fairly straightforward way to deal with that, too but I won't bore you with it right now.

 

[andrewm]

Well, I would hope that all the lines join up. My simple experiment was with a simple closed poly-line, so as far as AutoCad is concerned it is a single element made up of lines between several points. I was hoping that I would be able to do a simple push-pull on the resultant imported shape. However I will have a play when I get home.

Thanks,

Andrew

 

[andrewm]

I tried Dave's suggestion last night. I can explode the imported drawing easily enough but the resultant faces won't push-pull. However if I replace a line in the outline - any line will do - then I can get a face to pull. So it works but needs a bit of fiddling. For what I am trying to do that is fine. There are only four faces to deal with. So now I can get on with working out what to do next.

Steve, I will email you the file just in case you are interested but since this workaround seems to do the job please don't go overboard on my account.

Many Thanks All,

Andrew

 

[SketchUp Guru]

Andrew, if trying to Push/Pull those faces before tracing an edge doesn't work, my guess is there are no faces. Just satisfy my curiosity, start a new drawing and import the DXF, Turn on Shaded Display. Are the faces still the same color as the background? If so, there are no faces.

SU doesn't tend to create faces when importing CAD drawings. Steve mentioned the MakeFaces Ruby script. It is a free script and I can get you a link if you need it. It was developed by a SU user exactly because SU doesn't create those faces on its own.

 

[andrewm]

Dave,

I'll give it a try this evening. Unfortunately running SU at work may be a bit too obvious. Interested though that you say to import the DXF file. I have been using the DWG, native AutoCad file. Is that likely to make a difference?

Andrew

 

[SketchUp Guru]

Oh, well DWG works the same way. Should be the same. I rarely make any CAD drawings anymore so most of the ones I've imported have been DXF. I probably should have just said "CAD file" instead. Sorry.

You say it would be a bit obvious if you were running SU at work. You mean your boss might notice the piles of work stacking up around you and that you don't hear your phone ring?

 

[andrewm]

You say it would be a bit obvious if you were running SU at work. You mean your boss might notice the piles of work stacking up around you and that you don't hear your phone ring?

Rather I think the whole office might hear the few choice words when I fail to get SU to do what I want it to. :lol:

 

[Nick W]

Andrew,

PM me if you would like to meet up and work on this together. I have successfully used dwg files from and ACAD-alike in the past.

 

[Steve Maskery]

Hi Andrew,

'Twas as I said, you just need to create the faces first, either by deleting a line and putting it back in, or by using the Ruby plugin Make Face. Other than that, I had no problems. It was the DWG file that I imported directly.

Dave
THe outlines were imported as separate lines, just as if they had been drawn, they were not grouped (even though they were in AutoCad)

HTH
Cheers
Steve

 

[SketchUp Guru]

Not grouped? Hmmm..... I guess that's right although sometimes a CAD drawing seems to come in as a group.

 

[LyNx]

You may be having this problem because you are drawing the 2d AC plan as a series of lines and not polygon faces.

It's the same with ACAD, you can't extrude a series of lines until they are connected as a polyline or drawn as a polygon.

Andy

 

[andrewm]

Can I just say thanks to all who have helped me with this. I can now read in the parts that I need and am beginning to learn the complexities of putting things together.

Andrew