Contour lines not importing from DWG files

SketchUp
1

Hey all, new SketchUp Pro user here, apologies if this is a dumb question…

I am trying to import a DWG of a topographic survey. The contour lines and text are not showing up, only the lot boundaries. I understand that text import will not work without a plugin. No biggie. The contour lines, however are a problem. From the import results dialog, it appears that the contour lines might be out of range? Here’s a snippet of what I get:

AutoCAD Entities Simplified:

Coords out of range: 507

AutoCAD Entities Ignored:

Texts: 10

M-Texts: 56

X-Refs: 1

Anonymous Blocks: 41

Anonymous Block Inserts: 1

The elevation of the lot is around 900’ above sea level. When I load the DWG into Autodesk DWG TrueView 2026, it looks like the contour lines are 1:1 to that, i.e. they’re 900 ft above the layer with the lot boundaries. Everything in the file looks normal to me, but apparently SketchUp doesn’t like this. How do I fix this so SketchUp will import the contours in a way that the elevation data is preserved? Is it a range problem or do I need to explode the file? I don’t have AutoCAD unfortunately, and FreeCAD can’t import the file successfully either, so I’m not sure how I can explode the lines. If I use a 2D CAD app like Rayon, it destroys the elevation data. If I convert the DWG to a DXF there is no difference in result. Any thoughts?

Hobby mihai.s
2

It would help if you share the .dwg.

3

20250103-205JimBowie-Topo.dwg (733.8 KB)

Here is the original dwg. It has an external reference call, but I don’t have that file. Doesn’t seem to affect the ability to view the file though.

4

I suspect it’s the external reference that is getting missed.

Will this work for you, though?

5

The reason it doesn’t import is that it is not a pure AutoCad file but it has been created with AutoCad Civil that creates its own special objects.

image
image381×200 4.03 KB

You could ask the person who provided you with the file to give you a new copy made with the “Export to AutoCad” function in AutoCad Civil3D.

I wonder how @DaveR managed to get a 2D vector representation out of it if he doesn’t have Civil3D.

6

Thanks for the try DaveR, but that also destroyed the elevation metadata in the file. I was able to get that same output by routing the file through Rayon’s import function. But alas, I want that built in elevation metadata.

I think Anssi is right, I’ll just have to ask the surveyor to send me a different export type. Or just manually re-enter the elevation data in SketchUp. We’ll see how fast they respond :slight_smile:

Thanks for the help everyone!

7

I exported a PDF from TrueView, opened that in Inkscape and created a .dxf file which included the contours.

Sorry. As far as I could tell that wasn’t presented in True View.

As @Anssi suggested go back to the source and ask for a proper .dwg file.

8

odd, trying to import it in sketchup on my mac caused crash after crash. ( Crash #15333 and 34)
it opens fine in Qcad, and there I can flatten it in 2d,

Capture d’écran 2026-01-12 à 19.28.24
Capture d’écran 2026-01-12 à 19.28.241108×787 15.5 KB

and it imports in 2d as planned.

9

Importing that file crashes SketchUp.

@tiagoricotta could you look at Mac bugsplat 15335?

10

With the contour lines flatten its actually quite easy to make a terrain, the native way would be moving all the lines on the Z axis but one, and repeat for the number of lines the terrain has and use sandbox to create the terrain mesh. but using a plugin like toposhaper from Fredo, makes it a lot easier, faster and with a better quads mesh, like the one I made on this video. I don´t know the incremental dimensions on the Z axis so I just put a value on meters, the original file had foot or inches but toposhaper detects the units of your model.

11

Noted. Investigating.