Importing complex AutoCAD files

dwg
import

#1

I just acquired Sketchup Pro, and imported a complex dwg file with many layers. The entire CAD file opened as a single component, which I had to explode in order to work with it. While the many layers in fact show as different layers, they are all interconnected. How could I have opened the file and maintained the individual layers as separate components to avoid all the crossed lines now interacting.

The current situation has rendered the file a completely useless mess for me. I got this with the understanding that it could work with ACAD files.

It was a 2-D CAD file with plumbing, sewer, and gas lines running everywhere, and I need to shift some of the individual lines, which will now be, at best, a nightmare. Also, the color coding of the lines is lost which is equally frustrating.

Thanks


#2

There’s no need to explode a Component to edit the geometry within its context.
Right context click on the Component > Edit Component
Or, simply double-click on the geometry to open the Component’s editing context.
Then click in empty space to close.


By nature, SketchUp geometry is ‘sticky’.
Edges in the same modeling context meld together whenever they touch.

AutoCAD geometry behaves in opposite fashion.
AC lines remain separate, no matter how many cross one another.

SketchUp and AutoCAD employ layers as a means of controlling visibility.
Neither application uses layers as a means of isolating geometry.

The way SketchUp geometry is isolated is by ‘grouping’.
That is making selected sets of geometry into a Group or Component entity.


Prior to importing into SketchUp, create the separation you need in AutoCAD by making each logical portion into a ‘block’. Upon import into SU the AC block becomes a Component.

Another way is to export each logical portion of the AutoCAD drawing as a separate file on Layer0.
Each will become a Component upon import into SketchUp.

With that, the raw geometry within each Component will be on the Default Layer 0 where it must be.
Then, assign the Components (never the geometry within them) to new layers to control visibility.


Does SketchUp Support Layers — SketchUp Help




#3

I have worked with an earlier free version, and I understand the basic “stickiness” of Sketchup and the reasons for it, but it sounds like there is no easy way to e.g. move some pipes in an imported ACAD plan file of this type. I don’t own ACAD (for basic financial reasons) and was hoping to find Sketchup to be an adequate alternative since I like its interface and rendering abilities much better.

And as to the inverse, is there any easy way to export a file for CAD that would leave the components as independent lines, and not a hash-mix of short lines abutting one another?


#4

I forgot to thank you for your extensive reply! Thank you!


#5

Here’s a question: If I close out every layer save the ones I would like to be able to edit or move as an entirety, and select everything remaining on the screen, can I then create a component out of the contents of each layer manually, such that I can edit them without messing with everything else?

I admittedly have a ton of layers, and isolating them based on the cryptic names given by another does not sound like much fun, but has to be less maddening that what I’m engaged in now…


#6

The term ‘type’ is the root of the issue.
One can simulate 2D in SketchUp.
Nonetheless, it is a fulltime 3D environment with very different behavior from 2D CAD.

That begs the question…
Given the abundance of 2D CAD apps available, why use a 3D modeling app to edit a 2D CAD file?
Many 2D applications, Dassault DraftSight™ among them, offer a free version.

There’s a list of other CAD applications at the SketchUp Sage site.


SU’s edges will always break where they cross unless one practices the normal procedure of isolating geometry by grouping logical portions as the model is built.

Circle, arc and curve entities in a 2D CAD file export from SU become segmented as they are in SU.
Circle, arc and curve entities are preserved when you choose SU’s 3D Model export option. Like so…

Camera > Standard Views > Top
Camera > Parallel Projection
File > Export > 3D Model


#7

Upon import into SU, you’ll find some edge, arc and circle entities assigned to various layers will break where they meet while the bulk miraculously remains separate if left undisturbed.

In turning off all but one layer and grouping what remains visible, one can, in a dull sort of way, isolate the raw geometry of the CAD import according to its layers.

YMMV
Bear in mind … Invisible raw geometry assigned to a hidden layer still interacts with visible raw geometry.

One would still need to reassign the raw geometry within each group to the Default Layer 0
And then assign the group back to the appropriate CAD layer.


#8

Just for viewing AutoCad files, I would recommend the free DWG TrueView from Autodesk. SketchUp cannot fill that role, as the DWG import feature in SketchUp pro is limited to geometry (lines, polylines, extruded solids, 3D faces…) only, and, for instance, all textual information is omitted.

Anssi


#9

Well, thus far, I have yet to discover much to recommend Pro over the basic SketchUp 8 I learned on. I was hoping for some more flexibility in working with dwg files, etc. It sounds like I still need a good CAD app, and Sketchup’s purported import/export of dwg seems to be very lacking from what little I’ve been able to attempt.

I’ve admittedly not had as much time to play with Pro during the trial period since I have needed to produce some things, and I found the limitations with dwg’s to be maddening. (I haven’t gotten it to export to the same scale even, which seems really odd.)

I need someone to sell me on this before I uninstall it…

For the price of Sketchup Pro (as opposed to a cheaper ProgeCad with full interoperability with CAD) what am I really getting above and beyond what I had with my free version? It appears the dwg’s created in Sketchup are not of much use to e.g. engineers, or other trades that might want actual dwg files, and not pdfs.

I am not adept at CAD, and the learning curve for such seems a little steep. I used to draw by hand, but I need to be able to pass off dwg’s to third parties. Sketchup is intuitive for me, and easy to model and draw in, but I have yet to find anything approaching $700 in added value in the pro version.

As I say, my trial version hasn’t really afforded me the time to find out, and I’m old enough that I’m not as fast a learner as I used to be…

Thanks.


#10

Sadly a lot of people seem to have similar troubles.

I work daily with CAD (DraftSight - Free!) and SketchUp Pro, and still fall into some pitfalls. I’ve learned to adapt, not use hatches or weighted poly-lines, basically clean the CAD file to the bare necessities for import. Scale issues are on your end, have to define both in CAD and SU if you’re importing an Inches model into Meters well, that’s going to have adverse effects.

The power of SketchUp is being able to draw 2D in 3D. You can create very detailed CAD drawings via components and image patterns. Exporting DWG from Make is possible with purchasable plugins 100 / 150$ vs 700$ is a pretty good option.

http://www.simlab-soft.com/3d-plugins/dwg-exporter-for-sketchUp-main.aspx
http://www.sycode.com/products/dwg_export_su/

I use SketchUp Pro professionally, daily, and its paid for itself, its price point is very reasonable vs. other expensive options. Why I use SU over those programs is its SCALE, real world shadow tools, and its ease of adding a 3rd party render system without spending a few thousand bucks.

Ultimately if your goal is to create DWG’s a CAD program will be your best bet. But if you want simple tools that can get you to the similar results, SketchUp Make with $pay exporters and or Pro are certainly worthy. Good luck!


#11

I use them all free cad propgs some mentioned some not, I recommend Double Cad you can even open sketch up files in it.