SketchUp Raster Elevations into Autocad or Bricscad

Hi, I’m an Architect and have been using SketchUp since Version 2. It is very important to my practice.

My construction documents are done in Bricscad (a very good Autocad clone), all in 2D so no BIM or anything like that. But 3D modeling for almost every job is done in SketchUp.

I use raster images exported from SketchUp as elevations in my CAD program. Generally they look better than elevations drawn with vectors (assuming resolution is sufficient) and I can get material colors, shadows, etc. from SketchUp.

I have a system that works well enough but is somewhat cumbersome, and I wonder if there might be a better way (not Layout – that does not have the CAD functionality I need). I’m thinking of a plug-in to Bricscad or Autocad that might work the way you can import a scene into Layout and have it hot-linked to the Sketchup file. Does anyone know if that can be done or has been done?

For reference, here is how I do my elevations now:

  • Create the SketchUp model in sufficient detail with materials, etc.
  • Have the model on a terrain base that is a solid (it has the terrain top, flat sides, and a flat bottom) so that when it is cut in section the section fill will fill it in.
  • Starting with the widest side of the model, create a section cut through the base looking at the side of the building. Then select a face on that side and Align View. Then change to Parallel Projection view.
  • That leaves me with an elevation view of the building. Pan and zoom so that it almost fills the screen. Save that as a scene after getting shadows, etc. correct.
  • For the next elevation, don’t zoom – only pan and rotate view. That way the scale of the next view will be the same as the first one.
  • Rotate out so that the next side can be seen, create a new section, align face, etc. Save as scene.
  • Do this for all four sides or as many as needed. Each will be at the same “scale” on screen as the first one. That’s why I start with the widest one, as it will determine the scale.
  • Export each scene as a raster image. Usually 3000 pixels or 4000 pixels wide will do it, depending on how I plan to use the image.
  • Import the images into Bricscad as a raster (same process if in Autocad).
  • Scale the images to match the floor plan. So some length on the images is used as a reference against the same distance on the plan. All the images are scaled together as they were all the same “scale” when exported from Sketchup.
  • Use IMAGECLIP in the CAD program to trim the raster images as needed. Position them on the sheet (model space) and add notes, dimensions, etc.

When the SketchUp model changes, I have to re-export the images but if the size and extents of screen is the same, then it comes into CAD just file with the same alignment.

This is kind of cumbersome, though. If I had the scenes set up in Sketchup and could import each into CAD as one would in Layout, that would be better. Saving the scaling steps and making changes easier as they would update automatically like an XREF.

Could that be done?

If the raster output from SketchUp is good enough for you, you should definitely take a fresh look at LayOut. What is the CAD functionality that your current workflow (raster images into CAD) needs that LayOut lacks?

Well, if you use Autocad or a CAD program like that there are many features such as speed, XREFs, 2D drafting tools, block editing, interoperability with consultants, Autolisp programming, and so on that Layout does not have. Layout is fine for smaller jobs but it does not have the capability of a full-featured CAD system.

Other than it being much faster and utilizing SU to the fullest.

LayOut may be a portal for your own method. Since it is designed to take specific scenes into 2d format, you could use it as a go-between. What i do is have scenes in SU linked to LO and proper scale… In LayOut iI print pdfs via a routine that gives each page a separate file name. These are referenced in my CAD program. Revisions are very routine, print from LO ,automatically overwriting the previous file, and update the CAD references with a single command, where they come in cropped and positioned as the original reference. Unfortunately this is on Mac. But you may have similar process on Windows and ACAD, if you work it out.

I do something similar in Windows with PDFs exported from Layout into ACAD Architecture.

How about exporting DWG from LayOut?

The PDFs are of unannotated elevations or 3D views in hybrid mode with 1 elevation or view per page. Each page is a separate PDIMPORT on one or several DWGs. That way there’s only one PDF to keep track of.

I snap to vectors as necessary when doing the annotations in ACAD. When I make changes in SU/Layout, the references to the re-exported PDF are updated when I reopen the AutoCAD drawing(s) that uses them.

Agree with @Anssi , For accurate elevations you can set them up in LAYOUT to the correct sheet size and scale and export to DWG … and finish the notation in your Cad program for the compatibility you desire… the advantage also being that updates are more automated… you might find that you really dont need roll over to DWG in the end… or if you do it is only to export to others for their referencing needs

I can speak from experience on this method. I did this same thing for years between 2003 to 2008.

I would export raster images from SU, bring them into ACAD, then scale them to the CAD drawing I was trying to create. I did this for site plans, elevations and 3D details. It was faster than creating all the work in ACAD. At that time I had 24 years of experience with ACAD.

I finally jumped ship in 2009 to full use of LO. I had played with it for years but couldn’t quite get the hang of it since I kept trying to think of it like ACAD.

Once you get past this and figure out a good method of approach, there is no comparison in speed and graphic output.

Thanks all for the comments and suggestions.

I did try the Hybrid mode PDF export from Layout into Bricscad. The hybrid part is interesting in that is provides sharper lines. Otherwise that workflow seems like a similar amount of effort to what I was doing. It is still necessary to scale the PDFs when imported (although the scale factor is predictable rather than requiring reference to the plan) and if I want to be able to position each elevation on the sheet in Bricscad I would need to import each elevation separately, use PDFCLIP to remove whitespace, and then move them around – so similar to the raster import option. And then changes to the SketchUp model require opening Layout and exporting the PDFs again.

I will not get into the debate about whether I should be using Layout for my construction documents other than to say it is not for me. Others may be able to make it work well but for the scale of some of the projects I work on it just would not have the capacity.

So still my original question on this remains – would it be possible to have a direct import into Autocad/Bricscad of a SketchUp scene, at a defined scale? That would be less work than the raster approach or the PDF-via-Layout approach and in fact would provide many of the best features of Layout along with the capabilities of a full-featured CAD program. Perhaps I should be asking this question in the developers’ forum but wanted to see if anyone else has thought of doing this.

Maybe, @RichardMuller has some ideas?

Not at all what I’ve described. But I guess this is not what you want.

How big are these projects?

I don’t see these limitations you fear. Your approach is literally doubling your effort with no continuity.

But since you have no desire to hear why LO would be the better approach, carry on and I wish you the best in finding a solution.

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Sorry if I misunderstood your approach. Could you describe in more detail what you suggested?

What I did was open Layout, import the sketchup file and choose one of the saved scenes, then set the scale to what I wanted (3/16" = 1’-0"). Then I chose Hybrid rendering and outputted that view to PDF.

In Bricscad I attached the PDF and had to scale it by a factor of 12 x (16 / 3) to get it where measurements taken off the PDF were accurate.

Since the Layout export created a PDF of the entire page (with whitespace to the page boundaries) I have to use PDFCLIP to cut the image down to just the part I want to use.

In the past year or so I’ve increasingly moved toward using Layout for some projects and drawings, and in other cases, just use Layout as a portal to my 2D drafting app (I’m using the same stuff as @pbacot, but I think he’s got it even better automated than I). DWG can support raster images these days, but unfortunately, PowerCADD’s DWG translator doesn’t support that feature (even though the program itself has always supported raster images and can handle it). I’d like to know if the ACAD users here can say if they’re using that feature for this workflow, i.e. getting a hybrid result in ACAD.

What I have found for PC is that Hybrid setup in LO, exported/printed to PDF, then imported to PC can produce full hybrid results there with all the look of raster, plus accurate vectored lines to snap dimension tools to.

One thing I spent time doing was replicating my PowerCADD title block and stationery in Layout so the output looks the same. You can assemble a PDF set of drawings where some sheets came from LO and others from PC and it all still goes together.

I think what I’m looking for is sort of what you describe, but without the need for Layout. If there were a plug-in allowing hybrid-rendered SketchUp scenes to be imported into Autocad, then they would be treated just like XREFs, attached PDFs, or other externally referenced files.

The main hindrances to this sort of plug-in would likely be that Sketchup has it’s own Layout to support (sort of a CAD program) whereas Bricscad and Autocad have their own 3d modeling programs (not as simple as Sketchup) to support as well. Perhaps neither has a motivation to interface with the other. But maybe a third party could make it happen. I’m talking myself into it…

Yes, use LayOut and export to DWG. Using Raster or Hybrid mode in viewports produces a DWG with raster images that are directly to scale. Raster images alone cannot carry scale information, especially into CAD.

I don’t want to export the SketchUp file as DWG – that is useful sometimes, but you lose materials and shadows. Materials can be added back in Autocad as hatch patterns but it’s an extra step, and shadows are very hard to add back in 2D.

The raster images imported into CAD really are fine most of the time. At a high enough resolution they look good and I don’t do much dimensioning on the elevation anyway. I can enlarge them as needed to get to the right scale for printing.

Just to say again – I’m trying to avoid the Layout step. We all have different ways we like to work, and ideally the software would support different options.

Not if you export raster or hybrid rendered views from LayOut. Here is what I get, viewed in DWG TrueView:
Paper space:

Model space:

To be honest, myself, if I wanted to use Cad I would myself export Vector and apply hatches in the CAD app. But this would be OK too.