AutoCAD Civil 3D General

Active Member
Posts: 7
Registered: ‎05-29-2012
Message 1 of 3 (989 Views)

stl file

989 Views, 2 Replies
05-29-2012 03:37 AM

I´m having problem with creating stl file from surface. I need to import stl in another program for rockfalls.
I have create surface from contours, then extract faces, extrude them, union and I got solid..
I have export solid like stl file...
But in another program my surface is not smooth, like somethning went wrong while exporting stl, because in autocad civil 3D 2012 everything looks good.
I have found out how I can increase facetres to 10, but It has not affect to my stl file.
If there is some another parameter for better resolution of stl files?
Thanks for help!

Active Contributor
Posts: 29
Registered: ‎12-22-2010
Message 2 of 3 (933 Views)

Re: stl file

06-12-2012 03:00 PM in reply to: 0805110786

What is the name of the rockfall software you use?

You didn’t attach any picture so … I suppose that there is a problem because first you extrude faces and next you make union. The problem occurs because each face is extruded separately and finally the faces don’t fit to each other.


01. Extrude1.png


First try to make union and next extrude all the faces together, you’ll gain the full matching.


02. Extrude2.png


A full description of this method:

1. Select the rockfall surface in Autodesk Civil 3D and change the style to triangle
2. Export a drawing with a surface to the AutoCAD format (the best is the latest format)
3. Open the exported drawing and choose the 3D Modeling Workspace

03. 3D face.png

4. Select all the 3D faces from the exported surface and choose the Surface next select Planar

04. Planar.png


5. Select all the planar elements and choose the Union function

05. Union.png

6. Select solid and next choose the Extrude function
7. Specify the height of extrusion equal e.g. -10

06. Extrude.png

8. Type the BREP command and choose all the Solids to remove the history from the 3D solid
9. Select the Export function and next choose other format
10. Choose Files of type called Lithography with the (*.stl) extension
Select all the solids and press Enter, you will get your rockfall surface for further analyses

07. Result.png

Active Member
Posts: 7
Registered: ‎05-29-2012
Message 3 of 3 (909 Views)

Re: stl file

06-13-2012 06:56 AM in reply to: CivilFF

Thank You for Your help :smileyhappy:

I have solved part of a problem..
If I scale my solid and export it, my stl file is looking smooth in another program.
But I lost my dimensions.. what is very important because solid is representing a relief.
In drawing settings: drawing units are feet and scale 1"=40', but my model is in the meters.
If I change my units to meters, I do not know how to scale my drawing to keep my points at same location, is it possible at all? 

I got my base drawing from someone else, so I think that he did not care about units and he just drew it in meters. It is like my starting template and I need to do this scaling in relation to it. But my object (solid) is representing a piece of a relief placed in appropriate coordinate if I do the scaling of my object, this coordinate system remains the same and my object just "grows" in it. Is there a way to scale both of them?
This relations are important because I am exporting that solid/stl file in another program.

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