STEP export to Rhino got broken after F360 updated? File attached.

[anton.kuptsovEJSSW]

My workflow is often about exporting from Fusion to Step and further adjustment in Rhino.

This week I noticed that all fillets got broken in a very specific way - it build some extra geometry for filleted edges as if it were a torus object with OD= Filleted Radius.

This is the Fusion file http://a360.co/2yn3SBR

This is what you get in Rhino 5 after exporting from Fusion to STEP and opening in Rhino.

[et.teljemo]

Have you tried remaking the model and exporting the new one?

I dont use rhino but I 3d print. and sometimes if the model isn't water tight it can gett strange errors and shape shifting in the slicer software.

[anton.kuptsovEJSSW]

That's not the case.

All models (including the attached sample model) result in same undesirable behaviour.

[innovatenate]

Fusion 360 seems to read STEP the file okay if you import it back into Fusion. You may want to try export a SAT or an IGES from Fusion 360 to see if Rhino reads those file types any differently. 

I hope that helps!

[anton.kuptsovEJSSW]

As of this weeks for IGES and STEP result in broken geometry ((

[innovatenate]

Do you have the Join Surfaces option check when you're importing into Rhino?

Using an ACIS file format or *.SAT file might be another thing to try if you haven't yet.

[anton.kuptsovEJSSW]

Do you use Rhino 5? If you are, do you really have an import for SAT files?

[anton.kuptsovEJSSW]

If you really think that your suggestion is an actionable solution, please take 1 minute and try it out.

1) open the sample file http://a360.co/2yn3SBR or if you think the file is not good, you may redraw it in seconds.

2) export into STEP/IGES or SAT (if you can...)

2) open it in Rhino, here you may play with all those "Join Surface" options as much as you want.

3) share a screen-shot of the wireframe

Here's what you should get:

[innovatenate]

I'm a support specialist for Autodesk. I pretty sure I've imported an ACIS or SAT file into Rhino before, but I may be mistaken. It has been a long time since I opened Rhino. I'm definitely not a daily Rhino user.

Doing some quick searching it looks like you need a plugin to be able to import a SAT, sorry for any confusion there.

You can export a DWG from the Dashboard. This may be another route to try.

https://knowledge.autodesk.com/support/fusion-360/learn-explore/caas/sfdcarticles/sfdcarticles/How-t...

Did trying different import options on the Rhino side make any difference in the results?

Thanks,

[anton.kuptsovEJSSW]

Something changed in Fusion's STEP export, now they are using Nested Blocks (Block Instanses) which are strangely recognized by Rhino.

Any idea how to switch that off?

[innovatenate]

From the latest update's Read Me, I don't see any notes about any changes to the STEP export. I don't think we've made any changes here.

File Import/Export

• DWG files exported by Fusion don't display correctly in DraftSight due to lack of viewport support. You can use TrueView to save out to a DWG and it works.
• Importing large files can take a long time depending on your internet service. If you close Fusion during the upload, Fusion will restart the upload from where you left off.
• If you receive the error "Unable to upload file to server due to it currently being checked out. Upload will be retried." although there are no files being uploaded please contact Fusion Product Support.
• Autodesk Inventor assemblies may import with missing library components. This is a limitation due to the nested folders created with default Pack and Go settings. To avoid this, when preparing assemblies for upload to Fusion 360 using Pack and Go, be sure to enable the option Copy to Single Path.
• Uploading CAD files with a "$" in the filename may fail.

I'd also note that there are the cloud translators (the ones you use when you export from the Dashboard) and then there are the local translators (File > Export command). It might be interesting to see if there is any difference depending on which option you use. 

I can't think of a similar feature to nested blocks in Fusion. Something similar might be the Patch > Modify > Unstitch command before exporting to convert solid bodies into surfaces and then Patch them back together on the Rhino side of things. 

Is there any chance your default setting in Rhino were modified between now and the last time you imported a STEP from Fusion 360?

I hope that helps!

[anton.kuptsovEJSSW]

Setup was modified. Fusion was updated. Rhino 5 is static.

I've found that after the update, the STEP files from Fusion are recognized differently by Rhino, Rhino now sees that not as surfaces/polysurfaces, but as Block Instances, which (theoretically) can be further exploded into Surfaces/Polysurfaces. The problem is that new STEP exports from Fusion cause Rhino to build wrong Block Instances (see attached a screen from Rhino: torus-shaped artifacts for all filleted edges...)

See attached the original design in Fusion (with 1 fillet) and what it looks like in Rhino. 

PS. I checked local export and dashboard export - same result.

[HughesTooling]

This problem is as much down to Rhino as Fusion, the STP file in your first post opens fine in ZW3d and Geomagic. The reason you are getting blocks is because Rhino is not trimming the surfaces correctly so it's converting it to a block. I've seen this a lot with imports from Solidworks where a trim doesn't work and for some reason rhino then converts the collection of surfaces to a block.

I've also seen a lot of problems exchanging revolved fillets and tori between CAD programs so can you construct the part in a different way?

For example I tried using Split Face on a surface from a trimmed torus and it imports correctly.

Here is the before and after in Rhino and the split surface in Fusion. Also you should report this on the Rhino forum so they can tune up their importer.

Mark

[anton.kuptsovEJSSW]

Mark, thanks for your thoughs. I think you are perfectly right on each point.

However, maybe I didn't say it clearly in the beginning: this used to work OK for months, but after the recent update of Fusion the fillet issue appeared. So logically blaimed the update and I still do...

The problem indeed could be an issue of outdated Rhino5 STEP converter, or that could be a minor issue in Fusion's STEP converter which still can be resolved by newer software like ZW3d on your side and frankly speaking by Keyshot on mine.

Just it doens't work with Rhino anymore.

Expecting to hear feedback from other Rhino users.

[HughesTooling]

I can confirm something has changed. Here the part on the left was exported a couple of months ago and is clean, the part on the right is what I get now and the fillets are coming in as tori! @innovatenate I don't has the STP file any more from the clean version but something has definitely changed.

[anton.kuptsovEJSSW]

this is EXACTLY what i mean!

[HughesTooling]

@innovatenate Attached are 2 stp files. OldBolt is from last year and opens correctly NewBolt is what I get now and the fillet is not trimming correctly. Don't know if the files will be any help. The fillets in the new file are split into 180° sections like in the old version so not sure why there's a problem, has the accuracy used for export changed?

Mark

[innovatenate]

@HughesTooling Has anyone tested exporting from the cloud versus exporting with the local translator? I'd love to test, but I don't have easy access to Rhino. 

I've passed the findings along to the development team via report UP-36748. They'll be able to take a closer look and provide further information. There are things that sometimes don't make it into the ReadMe. 

Thanks all for sharing the information. If there is any difference in the local vs. the cloud translator, it would be good information to know. 

Thanks,

[anton.kuptsovEJSSW]

@innovatenate

I tested yesterday dashboard (cloud) export and local export

both result it same artifacts

I didn't try dashboard (cloud) export earlier when local export was OK

[innovatenate]

I just received an update from our development team. After some investigating, they have determined that the issue is not in the Autodesk translators. There is a Rhino import bug/weakness exposed in Rhino 5, but the good news is its slated to be fixed in 6.

I was informed that some preliminary testing in a Rhino 6 beta (codename Serengeti) showed improvements.

See this thread as an example in the Rhino forum.

https://discourse.mcneel.com/t/step-file-from-creo/48815/2

I hope this helps!

Thanks,