Importing and cleaning STL files

October 12, 2006, 12:12

Hello Everybody !

Does anybody know how to clean-up STL files ? I have a task to investigate external aerodynamics of a car with new design and for my work I received as a start point a STL file which contain geometrical data of the car. That STL files was constructed via laser scanning and contains enormous amount of data - over 2 milions vertices and approximately 700 000 faces. So, I have to clean-up it. I've dealed before with IGES file and everybody was OK, I read also carefully GAMBIT tutorials concerning importing different file format but noting for STL was wrote . Have anybody experience with STL-files ? Please, help.

October 12, 2006, 19:54

Hi peter,

What do you want to know. If your model has got 700000 faces what ever neutral file format you bring it in its goin to have the same amount.

You need to carefully have a look,delete and recreated few of the surfaces.

Can you please post me the neutral file if it is not confidential.

My email Id is aparajits@vipac.com.au

Thanks Regards Rajit

October 13, 2006, 06:41

I recently saw a presentation by an ICEM specialist, working for Ansys, mesh the outside of an engine block, imported in .stl format with 2M faces. The technique was called "shrink wrapping" and involved placing a 2D virtual sheet over the geometry and thus ignoring any internal unnecessary internal faces and de-featuring the external ones. A mesh of varying coarseness can then be placed on the virtual sheet. The whole process took about 10 minutes. Also, CD adapco have a similar technology that they liken to blowing up a balloon inside a CAD geometry to achieve what I believe to be the same result but for internal parts.

I would suggest contacting Fluent to see if they have any similar facility. One of the best ways of getting answers is to explain how their competitors (if indeed they still are) do it better.

Good luck.

October 12, 2006, 12:12	Importing and cleaning STL files	#1
Peter Guest Posts: n/a	Hello Everybody ! Does anybody know how to clean-up STL files ? I have a task to investigate external aerodynamics of a car with new design and for my work I received as a start point a STL file which contain geometrical data of the car. That STL files was constructed via laser scanning and contains enormous amount of data - over 2 milions vertices and approximately 700 000 faces. So, I have to clean-up it. I've dealed before with IGES file and everybody was OK, I read also carefully GAMBIT tutorials concerning importing different file format but noting for STL was wrote . Have anybody experience with STL-files ? Please, help.

October 12, 2006, 19:54	Re: Importing and cleaning STL files	#2
Rajit Guest Posts: n/a	Hi peter, What do you want to know. If your model has got 700000 faces what ever neutral file format you bring it in its goin to have the same amount. You need to carefully have a look,delete and recreated few of the surfaces. Can you please post me the neutral file if it is not confidential. My email Id is aparajits@vipac.com.au Thanks Regards Rajit

October 13, 2006, 06:41	Re: Importing and cleaning STL files	#3
Andrew Garrard Guest Posts: n/a	I recently saw a presentation by an ICEM specialist, working for Ansys, mesh the outside of an engine block, imported in .stl format with 2M faces. The technique was called "shrink wrapping" and involved placing a 2D virtual sheet over the geometry and thus ignoring any internal unnecessary internal faces and de-featuring the external ones. A mesh of varying coarseness can then be placed on the virtual sheet. The whole process took about 10 minutes. Also, CD adapco have a similar technology that they liken to blowing up a balloon inside a CAD geometry to achieve what I believe to be the same result but for internal parts. I would suggest contacting Fluent to see if they have any similar facility. One of the best ways of getting answers is to explain how their competitors (if indeed they still are) do it better. Good luck.