🐞 BUG: Layout metric DWG output not accurate

LayOut
1

Hi. When I create a metric SU file, add it to a metric LO file and output to DWG, the resulting model space is not accurate. Real example:

300.00001 mm instead of 300 mm.

Some measurements become a tiny bit smaller, some become a tiny bit larger, so it’s not a scaling error.

However, if I take the same model and output directly from SU, the resulting DWG is perfectly accurate.

This only happens in metric. I tried the same experiment with an Imperial workflow, and LO outputs perfectly accurate DWGs.

How to solve this? For now I’m stuck with re-outputting everything again from SU and copy-pasting to the resulting DWG.

I’m using SU and LO 2017.

2

Can you post a small example, preferably the .skp or Layout file?

1 Like
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Sure! Here’s a simple one meter square .skp with the corresponding .layout and resulting .dwg.1 meter square.skp (129.5 KB)
one meter square.layout (114.6 KB)
one meter square.dwg (13.7 KB)

4

It is probably a feature of all digital representations of numbers. SketchUp stores internally in inches, so it might cause conversion errors.
What effect does the 1/100 000 mm error have to your work?

5

Thanks, Anssi.

Well, I do believe it’s a bug because:

  1. If I export the same thing directly from SU, it’s perfectly accurate.
  2. It never happens is you use imperial measurements in both SU and LO… Even if the project was originally designed in metric and you hard-converted it to Imperial using the tape measure tool.

I actually tried this experiment: A house I designed originally in metric and then inserted it in LayOut was having this problem. So I tried this: I hard-converted it to Imperial in SU (30cm became 1 foot), switched to architectural units in both SU and LO and re-tried LayOut export to DWG. The result was a perfectly accurate DWG. So, even though the end result should have had a bigger error due to all the conversion, the end result actually had zero error.

At least for me, I can’t deliver a DWG file with these tiny errors. It’s just not professional, and the person who tries to edit or modify the DWG will just assume that either I or the software I use is not accurate.

I’m attaching the square after hard-converting it to Imperial in SU and changing units and scale to Imperial in both SU and LO. The resulting square in the exported DWG has exactly 40 inches on each side, despite having been scaled from one meter.3f 4in square.skp (129.4 KB)
3f 4in square.layout (114.5 KB)
3f 4in square.dwg (13.5 KB)

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