Hows the STL functionality working for folks?

OpenR2

Took a break from OnShape for a while ,,, the STL functionality lured me back.
So hows the STL functionality working for folks?
I tried importing two files.
Both are uploaded but only one converts to part studio,
Says part failed validation.
But I can read this STL in to every other CAD program and mesh program that I have loaded on my computer.
Grrrrrrrrrrrrr.

viru

@OpenR2, Now it is possible for user to import, view, edit and save STL files in Onshape with the help of STLWorkbench. I am very excited about new App (STLWorkbench) which is introduced in Onshape app store recently. STLWorkbench has robust, fast, automatic functionality for analyzing and processing the STL files or meshes which will brings one of the most exciting additions added to Onshape app store yet.

OpenR2

Viru, 

I took a look at this a few months ago and it really didn't do anything for me because I was looking to integrate STL models as background into my assemblies. I was also not very excited that the interface did not seem to really follow the OnShape interface look and feel. It felt like a completely different app that was being opened in side a window inside OnShape.

I do have an STL file that Lou says is failing the body check when importing into OnShape. It would be an interesting exercise to see if you application has the capability to determine where the issue is and correct it in a manner that allows it to be imported. Is this something that STLWorkbench can do? Do you have a user guide or how to that shows how to do it?

Robert

viru

@OpenR2, Yes STLWorkbench have that capability. STLWorkbench automatically fixes issue and correct them into printable form. Kindly refer below video for more detail which will helpful to you.

joe_dunne

Definitely try STL workbench if you have issues with importing a STL model. STL files are very prone to errors, bad geometry,  lack of accuracy. Yada yada yada....  

That is exactly the problem STLWorkbench is designed to address. Fixing problem STL data.

Start by using the the automatically fixed STL file.
If this still proves to be a problem,  try the simplify option.

One of these two options seems to work for just about every problem STL I have encountered. 

Onshape will continue to make reading STL data more tolerant as time goes on. However it's a bit of game of Whack a Mole, gaps, bad data etc.. The technology behind STLWorkbench represents a LOT of research, lots of man hours and resources. So with the combination of Onshape and STLWorkbench you have a pretty robust solution. 

Joe

OpenR2

Joe,

I am a little confused.
STL is simply an array of triangles with per triangle normal information.
It does not get any simpler than this.
There is no geometry in the file other than floating triangles.

The request for STL was to be able to import STL files into the assembly to be used for reference.
It looks like OnShape is trying to enforce the requirement of a continuous closed mesh? Why? We don't need that for reference.
I can open these STL files in every other application I have tried....I am guessing because they are not trying to force the requirement that the STL be anything more than STL to import as STL.

Its really frustrating to wait this long for functionality and then find out that we don't really get STL support.
We have STL support for a subset of STL files that are of a certain criteria that meets the requirements for some downstream applications.

Can we just start with reading in an STL file?
If the file has no parsing errors....then it should be loaded.
Yes?

Robert

OpenR2

OK so I load the STL into the STL Workbench
But it shows no Open Edges and no Self Intersections.
So obviously STLWorkbench can load the original STL ... so why not just load the same raw STL in the OnShape document?

OpenR2

OK.
So I figured why not save out the "unchanged" STL file from STL workbench and try to import into OnShape.
This imports.

OpenR2

Now I am really frustrated.

The STL import gave no information about why the import failed.
I opened a ticket and was given a little info about not being able to recognize the STL as a body.

I am told that STL is very complicated (LOL) but restrictions may be relaxed in the future.
I am told a partner tool may help "correct" my "bad quality" STL.
The partner tool shows there is no error with my STL.
But ... saving it out of the partner tool and back into OnShape works.
So this just leaves me feeling a bit like Ive been to the used car lot.

I opened an problem ticket on this issue and have no real information about if its being looked at. Or if there is a problem with my STL. Or if there is a problem with the OnShape STL importer. Or if maybe the partner tool did a correction but didnt report it. What ever it is. The conversion with OnShape so far feels more like deflection than problem resolution.

For $100 a month this is not the kind of problem resolution I would expect.

So how do I find out what caused the problem with the original import. The actual technical reason why the import failed?
How do I find out if any data changed between the original STL and "repaired" STL in STL workbench?
How can I determine if the problem with the imported was specific to an ascii STL vs a binary STL?
How to we document what "fixed" the problem?

joe_dunne

OpenR2

STL is not a format that is complicated. It's more that it is prone to many "problems" 

self intersections
Flipped normals
zero area faces
Orphaned triangles
Lack of closed volume
Gaps, holes, etc... 
Just to name a few

Onshape's current requirements STL are very similar to what most 3D printers typically have.. You cannot print an STL model with these types of errors either.

Just to be clear, you were able to get the STL file to import into Onshape correct?

Onshape takes an approach of Agile software development. One of the tenets of this approach is we do smaller more "agile" projects. This means you get access to new functionality much faster. It also means sometimes there things missing we wish were there. It's a trade off. But I think this is better way to go. This also allows us to hear from you what needs to be added next, vs "thinking" we know everything ourselves.

STL import functionality has just been released. Rest assured it's not done, there will be more capabilities as time goes on. Feedback and diagnostic tools are high on the list.

Also I am working with the STLWorkbench team to streamline the workflow for fixing and importing the STL data. Remember it was designed as a tool to fix STL files in preparation for 3D Printing.  Now that Onshape added import, they are looking at making that workflow a bit more obvious as well. So I anticipate the repair process in STLWorkbench to have improvements too.

Joe

OpenR2

Joe,

Yes. I was able to read the STL file into OnShape after loading into Geometric's STL Workbench....which reported no errors and no corrective activity. Luckily I was able to do this for free and no have to purchase the STL Workbench. I would have been furious if I had spend more money to read in an array of 3 point + a vector sets.

Agile has nothing to do with what the customer sees. Any programming team that was worth anything in the past 20 years has used an agile philosophy. Todays latest buzzword for something that we've all been doing for the last 20 years doesn't have anything to do with the discussion we are having.

What difference does it make that the STL file has any of those issues? The STL functionality as advertised by OnShape in the latest release is that STL can be imported in to be used as reference in your designs. Putting a restriction on the quality of the STL makes no sense at all. I am not going to print the mesh down stream. I just need the points as reference for mating parts or for reconstructing the part as a solid.

So what I am not getting from my ticket or the forum is what was wrong with the file. Which gives me 0 confidence that you have looked at the issue, the you have determined what the issue is, or that it will be fixed next release.

Just thinking of reasons why you would need a "clean" STL file could be something like you need a closed body for your STL section cut code to work correctly. Is this the case? But thats the opposite of Agile. Instead of getting the ASCII and binary importers working rock solid in the first release you would have gone a very non-agile direction and compromised the stability of the importer itself for the Gee-Wiz of the section cut.

The question that I would like answered is what was wrong with my ASCII STL file that simply reading it into STL Workbench and writing it back out as binary STL fixes the OnShape import. No redirection. No "in the next version". No "how would you feel if we incorporated your STL into our test process" .....

Just tell me what was wrong with the ASCII import that the Binary import fixed.

Meanwhile I will find something that converts the ASCII to Binary without any other changes and determine if STL Workbench did a fix it didn't report or if its the difference between your ASCII or Binary parser.

OpenR2

Viru,

Looks like doing a straight convert to a binary file resulted in the binary file still failing the import.
This points to the STL Workbench making changes to the file that are not being reported.
OnShape has the capability to open a bug report .... but how do you open a bug report with an OnShape app partner?
How do I report this as an issue and work with Geometric to identify the modification that was made to the STL file?

Robert

joe_dunne

Using the feedback tool while active in an Integrated App tab sends the report to the appropriate partner

joe

OpenR2

Joe,

Great. I will send them feedback with the feedback tool.

How does the OnShape partner gain access to my data or to the logs generated from my data? Isn't my data completely secure on the Amazon (or is it Goggle) servers? 

Robert

joe_dunne

OpenR2

As part of the Integrated Cloud App qualification process, support mechanisms are enabled and tested between Onshape and the Integrated Application. So that when the feedback tools is used it automatically feeds into the appropriate partner mechanism.  

Permissions are handled by the user. The user grants an app permission to access the user's data.  Each app also spells out their privacy policies and can be found in their respective App Store entry.

Joe

OpenR2

Does that mean the partners app may not be running on the hardened Amazon (or is it Google?) servers? Or that if I give them permission to the data it could be streamed out of the OnShape environment?

So wait....now I'm becoming really uncomfortable. So the App Store applications aren't guaranteed to abide by the infrastructure guarantees that Onshape laid out in its sell on their implementation of the cloud? And I'm expected to read each partners terms? Understand them? And keep up with them as they change?

billy2

Just wanted to report no issues with stl or obj import/export.

I've been using them a lot.

stl mainly for export
obj mainly for importing scanned data

john_rousseau

Hi @OpenR2. Thanks for the good questions. It's important for our users to understand what Onshape is doing here to protect your data and what responsibilities you have.

When we onboard our app partners we are clear with them about the importance of safeguarding end user data. We provide them with documentation on best practices for protecting your data in motion and at rest. We let them test against a development version of Onshape so they can fix any issues before going live with a new or updated app. With that said, we do monitor their traffic against our APIs for signs of problems and abuse. 

However, the servers that our partners use are under their control, not Onshape's.  Once you allow a partner access to your data, they have access to your data. This is why we explicitly require you to give them access and have provided you controls on how much access they are given when you sign up for the app. We require partners to use encryption to access your data, but after the partner has accessed it, it's under their control. Our API partners have their own products and their own infrastructures, some of which are desktop-based. We don't have any technical way to validate how they are handing your data once you have given them permission to access it.

If you have any concerns with an Onshape partner to whom you have given access, just revoke access for that app.

-John

lougallo

@OpenR2 It is also important to note in @john_rousseau 's comment, that in your Application preferences under Manage account you can turn on 

Control application access to my documents individually through the share dialog?

This slider will then allow you to only add applications on a per-document basis.

ivan_volpe

I don't get the point... in my understanding, I can only "open" an STL but not "import" a STL object into an Assembly and use it as a "part". Am I wrong? It looks quite useless!

owen_sparks

ivan_volpe said:

I don't get the point... in my understanding, I can only "open" an STL but not "import" a STL object into an Assembly and use it as a "part". Am I wrong? It looks quite useless!

@ivan_volpe I don't usually jump to the defense of SW companies but in this case feel compelled to do so.  OS is new, revolutionary and is opening up CAD to a whole new market.

2 weeks ago we couldn't do anything with STL files.  Today we can import them (when they work) and use as reference geometry.  Every 3 weeks (roughly) there's an update to OS.  The last two have had some really good stuff in them.  I'm sure there's more to come in STL-wise in he not to distant future.

Previous updates plugged the holes that prevented me from using OS for work.  The devs brought the package up to a level that made sense to go pro, and OS continues to grow.

As mentioned earlier perhaps reverse engineering an stl is often better than using it as a part.  On the other hand using a mesh for the topography of a construction site in architecture, or as a scan of a healthy limb to make a matching prosthetic one are a couple of examples where what we have now is useful.

[soapbox mode /off]

Cheers, Owen S.

 

dik_harrison

I have just used STL workbench to import a problem STL.  I then exported the file and imported the fixed file into OS.  The document has a part studio, but I cannot insert it into another document to use to test for fit and clearance.  I also imported the same fixed STL in the the document in which I want to do the testing, and a parts studio was created there also, but again I cannot use it in the assembly to test for fit and clearance.  Is there any way to accomplish this?  I really like using OS for some of my smaller projects, but this is proving to be a bit of a difficulty.