Importing .stl files

watkins · 13 Mar 2008, 17:37

I posted this topic this morning, but I cannot seem to find it, and so I assume it was affected by the recent bug.

Does anyone know if there is an IMPORTER for .stl files. I know there is an exporter written by Didier Bur, and was wondering if an importer existed. I am using the free version of Sketchup 6.

cdubea · 13 Mar 2008, 17:43

I haven't found one yet. Hopefully there is, but I doubt it. It would be a good tool to get models out of SolidWorks and into Sketchup. At present I export to ACIS files from SolidWorks and then open them in IntelliCAD (DWGEditor which came with SolidWorks) at which point I can save a 3D dwg file which can be read by Sketchup. But these are really not very clean imports.

Take care,

chris

remus · 13 Mar 2008, 17:47

I havent tried this before, but you could try using blender to imort the .stl and thene xport it as soemthign more SU friendly.

Anssi · 13 Mar 2008, 18:36

Deep Exploration can convert between the formats, but it is not free, costs about the same or more than SU. Luckily STL is supported by the Standard edition, as the CAD version is quite expensive.

Anssi

watkins · 13 Mar 2008, 21:07

Dear All,

Many thanks for all the replies.

Regards,
Bob

Didier Bur · 14 Mar 2008, 16:12

An importer could be quite easy to write (I remember an old Autolisp routine of mine some years ago...). The problem could be the exact format of the STL input: there are binary and ascii formats and within these two kinds of files, sometimes keywords may vary, and scientific notations as well. I used some of these for rapid prototyping and this was (sometimes) a nightmare...
Please post an sample STL file so I can take a look at it.

Gaieus · 14 Mar 2008, 19:18

Post it zippedas the forum may (not may but does) notallow that format.

Didier Bur · 14 Mar 2008, 21:05

I have published an import STL script here:
http://www.sketchucation.com/forums/scf/viewtopic.php?f=153&t=8081
It's added to the previous su2stl.rb script.
Plugins menu -> Export STL file / Import STL file
There are 2 samples for tests in the zip archive.
Supported format is the most common STL ascii format.
Regards,

watkins · 14 Mar 2008, 22:33

Dear Didier,

Thank you so much for all your hard work. I am always amazed by how quickly a request becomes a reality. I will let you know how I get on with the new script.

Once again, many thanks,
Bob

watkins · 15 Mar 2008, 12:47

Dear Didier,

Just a quick follow up on my previous post.

I created a Sketchup model of simple machined/punched shapes (see the attached file), exported the model as a .stl file, then imported back into Sketchup using your new import option. Apart from some minor cleaning up it worked very well. I used the Delete Coplanar Edges script to remove a lot of the redundant lines and then the erase tool to remove the remaining lines. Interestingly, the through circular hole needed re-cutting, while the elliptical hole was just fine. Ah! The mysteries of life!

Once again, thanks.

Regards,
Bob

Test_piece.skp

Didier Bur · 15 Mar 2008, 21:29

Hi Watkins,
Redundant lines you mention are due to the STL format which only contains triangles (as you probably know) and the re-cutting on some holes are sometimes due to decimal precision (10 e-14 in SU) and in some cases that is not even sufficient. I've encountered from time to time an error message from SU: "Points are not planar" when reconstructing a model from a STL file with this script. Go figure... This is rather stupid because 3 points are always coplanar.
Regards,

watkins · 15 Mar 2008, 22:36

Dear Didier,

Yes, I knew about the redundant lines issue, but the glich with precision was new. I'm sure this will become a very useful script. I have asked a colleague of mine to create a 3D model in AutoCAD's Mechanical Desktop, and then to export to as a .stl file. I will let you know the results.

Thanks again,
Bob

cdubea · 17 Mar 2008, 18:44

In any event, thank you for providing this. Hopefully it's better than the method I was using to get SolidWorks models into Sketchup. I'll test is later today and report back.

chris

watkins · 17 Mar 2008, 19:21

Dear Chris,

Let me know how you get on. I use Inventor myself, and would really like an .iges export option for Sketchup. I like to mass model in Sketchup because it is so quick and easy (creative juices and all that).

I recently tried importing a Swagelok coupling as a .dwf file (downloaded from the web) and it sort of worked (needed a lot of cleaning up, and the remaking of faces).

Regards,
Bob

cdubea · 18 Mar 2008, 00:39

@watkins said:

Dear Chris,

Let me know how you get on. I use Inventor myself, and would really like an .iges export option for Sketchup. I like to mass model in Sketchup because it is so quick and easy (creative juices and all that).

I recently tried importing a Swagelok coupling as a .dwf file (downloaded from the web) and it sort of worked (needed a lot of cleaning up, and the remaking of faces).

Regards,
Bob

I really didn't have much success. Attached is a zip file with a 3d pdf of the part I exported from SolidWorks, the .stl file and the resulting Sketchup file.

You can see the results leave something to be desired.

Thanks

chris

RMH.zip

watkins · 18 Mar 2008, 07:51

Dear Chris,

As you say, disappointing.

Did you see the link to SpaceClaim posted a few days ago?

http://www.spaceclaim.com/

Regards,
Bob

cdubea · 18 Mar 2008, 12:18

@watkins said:

Dear Chris,

As you say, disappointing.

Did you see the link to SpaceClaim posted a few days ago?

http://www.spaceclaim.com/

Regards,
Bob

I'm familiar with SpaceClaim. Michael Payne was one of the architects of SolidWorks many years ago and left when Dassault Systemes bought SolidWorks. I've been involved with SolidWorks since '96.

The pricing on the LT version is very reasonable. If I'm not mistaken, the pro version is done on a perpetual lease basis. It's a nominal fee up front with an annual fee to use the software.

watkins · 18 Mar 2008, 12:29

Dear Chris,

Thanks for the additional information. I will request a quote for the LT version and consider using it as a mechanical design alternative to Sketchup. I will check to see if SpaceClaim LT will export .sat, .stp and .igs formatted files.

Regards,
Bob

Didier Bur · 18 Mar 2008, 12:40

Hi cdubea,

with rmh.skp, I got the following message in the console:
Error: #<ArgumentError: Not enough points - at least 3 required>
If you open the stl file in a text editor, you'll see that coordinates are given in scientific notation (vertex 4.613638e+000 2.150841e+000 7.951958e-002 for instance). That doesn't disturb Ruby, but values are very small, this may be the problem (with SU autosnap feature I guess).
An intersting test would be to scale your original model by 1000 or 10000, re-export the stl and see what's happening then when importing in SU.
Regards,

cdubea · 18 Mar 2008, 17:24

@didier bur said:

Hi cdubea,

with rmh.skp, I got the following message in the console:
Error: #<ArgumentError: Not enough points - at least 3 required>
If you open the stl file in a text editor, you'll see that coordinates are given in scientific notation (vertex 4.613638e+000 2.150841e+000 7.951958e-002 for instance). That doesn't disturb Ruby, but values are very small, this may be the problem (with SU autosnap feature I guess).
An interesting test would be to scale your original model by 1000 or 10000, re-export the stl and see what's happening then when importing in SU.
Regards,

No problem. I'll give it a try and report back.

chris