Checking if imported STL file is closed

[ProFeature]

Hello, community!

When I import a stl file, I have no way of knowing whether it is closed (other than the visual search for a green colored hole).

Is there a simple way to ensure that the imported STL file is closed?

I appreciate the responses in advance.

Thanks

[tbraxton]

Import data doctor has some tools to help identify and correct geometry of import features. Having said this, the quickest method to identify open quilts is to use a custom color scheme to increase contrast of open edges of quilts. I would typically use a black background and display the import geometry in wireframe and look for the open edges based on the color. You may need to zoom in on areas to see them.

About Import DataDoctor in Creo (ptc.com)

[ProFeature]

Thanks @tbraxton @, but your answer does not meet my need at all. I'm asking about facet model, and IDD doesn't check stl.

Thanks

[tbraxton]

What version of Creo are you working in? Do you have a "bad" stl file as an example that you can post here? If the import data is not closed, is it not a surface model when imported? If it is an open quilt upon import then IDD should be accessible.  In past releases that is my recollection of what happened when importing STL into part mode, perhaps that has changed with new versions.

To edit facet models, you need to use the Creo Restyle extension which is an optional add on. If you have this option installed, then you can access this functionality to close holes in a facet model.

To Fill Holes in the Faceted Geometry (ptc.com)

[ProFeature]

Hi @tbraxton 

I work with Creo 10. I've attached an example of an open stl (which I opened 😎).

 

I repeat, IDD does not support imported STL files.
The concept of using a dark mode is well-known, but it is a "nice to have," rather than a definitive analysis. The question of "where" is secondary.

[tbraxton]

IDD will not work with facet features in Creo 7+, I am not sure in what release this changed as IDD at one time did deal with STL import data. This shows how long it has been since I faced this issue of bad STL mesh.

For facet features REX module is required to work with them. I am not aware of any automatic validation tools to check the STL data on import and identify specific geometry issues. I am not well versed in the use of the REX module but maybe others here can offer some insight into workflows or best practices.

[StephenW]

For stl files specifically, there are some online repair tools I have used on occasion. I don't remember which one(s) i have used but I just google for STL repair tool 

[ProFeature · Accepted solution]

Hi all,

I found that measuring volume is the simplest test to determine whether the model is closed.

If the volume measurement value is not zero, then the model is closed.

Open:

Closed

Thanks

[KenFarley]

I think people were thinking that you wanted to know how to fix an STL file if it was missing a facet or facets.

It's possible to fix them if you really need  a manifold solid, but it's not an automatic thing.

You need to have the STL file in ASCII format, not binary. If your source file is binary, you can re-output it to ASCII after reading it into Creo.

Using any of the techniques mentioned here, find the missing facet.

Do an analysis of the missing facet vertices, recording the X,Y,Z coordinates for each.

Edit the ASCII STL file and add in another facet structure. You'll need to use the vertices to calculate  the facet normal vector. It's the cross product of two vectors defined by the three vertices.

If you add in all the missing facets, the object should be a manifold solid. Hopefully.

[ProFeature]

Hi @KenFarley 

My topic was determining whether an imported model is closed (yes or no). I found the answer to this question by measuring its volume. The issue of closing holes is secondary.

There is a convenient tool in Creo for closing holes, so I don't see the point in manipulating the STL file's ASCII.