Importing step files and material/appearance issue

[mbostonsprint]

I have a large assembly I have imported from Solidworks, and I subsequently extracted a subassembly from this import, and put it into a New Design via copy/paste (new, I think). I was able to change the material and appearance of parts in the subassembly within the large full model successfully (from steel to PET plastic as material,  and transparent polycarbonate for appearance). After I extracted the subassembly (with the changed properties), and opened the subassembly model in its own model file, I have been unable to successfully change the final appearance of the same parts and have it stick.

I have tried changing the parts as a group selection, and individually, selected from the browser, and this seems to have worked when I check properties. During the material and appearance assignmrent everything looks like it is going to work, but after I finish the change command activities, the on-screen appearance reverts to default steel, even though the properties have been changed successfully.

Any ideas about what is going on? Is there some known issue with imported step files? I am puzzled because of the apparent success with the full model where everything worked.

[Phil.E]

Hi,

A couple things are going on here:

• STEP files all arrive in Fusion with "face overrides". Meaning the appearance color is applied at the "lowest level". Sometimes this makes it harder to change the appearance of an imported design, but not impossible.
• Designs have Physical Materials and Appearance materials. Such as "aluminum 6061 that is blue anodized".

Can you clarify what your workflow is here:

"During the material and appearance assignmrent everything looks like it is going to work,"

I ask because Physical and Appearance material assignment does not happen in the same command dialog.

What happens is when you apply Physical Materials, and that dialog is open, the model bodies will discard Appearance materials (i.e. "blue anodize") and show you the visual of the Physical Material, such as "brass". This is intended to help you see "what the parts are made of" while you are busy adding or editing "what the parts are made of". When you are done, the Appearance of the part is restored and they will change appearance - if they carry an Appearance different than their physical material.

Is it possible you are seeing this? If you could share one of these STEP files I can give a much more to the point answer. Glad to help.

Thanks,

[mbostonsprint]

Hello, Phil --

Thanks for the response. I decided to try this operation again, just to make sure of the circumstances where the difficulty is occurring. This may be slightly more definitive:

I imported the full assembly model from Solidworks step file.

Changed the piece parts of interest (qty 4) from default characteristics to material PET plastic (first) then changed appearance to polycarbonate clear (second). This operation was performed at the "Body" level in the browser. This worked as expected, so that I ended up with the parts being transparent when present in the full model.

Next, I selected the subassembly (with the now-changed parts) in the browser, and performed a Copy (right-click menu), opened a New Design. and performed a Paste New operation to bring in the subassembly of interest. I rotated the subassembly for favorable orientation, and clicked OK. Subassembly is now present in the New Design with NON-transparent parts (default steel opaque look), but in checking the properties of the parts of interest, they show PET plastic material, and clear polycarbonate as appearance.

I find this quite strange, as it worked just fine in the full model, and the properties are being carried with the copy/paste to the new design. My comment about "it looks like it is going to work" meant that during the operation of the command steps the correct appearance would show up, but on conclusion ("OK") the appearance would revert to opaque from transparent.

I can send you something via email if that helps.

[Phil.E]

Sure thing. I could use the file to test this. I'll send you an email in a few moments.

Thanks,

[mbostonsprint]

Phil -- Thanks for the email response, but I just figured it out:

 I found the issue remedy. In the very top level in the browser, there is an "appearance override" menu item that I was unaware of in working with the extracted subassy. This is above the document settings/named views/origin items. I had been only working at the main subassembly level immediately below that, where all the items in the subassy can be selected and manipulated.

By removing the appearance override at the top level, all seems fine now.

So, I'm still not sure what I did differently in the full assembly model, but I'll look further into this process on the next occasion. I seem to recall that there were additional dialogs when I made the changes within the full model, but those seemed like par for the course at the time.

It's still a mystery to me as to why the appearance carries over from the imported step file through a download and save of the changed full model, and then through a copy into a new design. That's some persistent genetic material;-)

[Phil.E · Accepted solution]

@mbostonsprint haha, you got it.

When you import a STEP file, the chief advantage over something like SAT, is that browser structure is preserved, and appearances are "preserved". Fusion translates them into RGB values.

You can see this when you open Appearances, and then look in the "in this design" section of the dialog. There should be a handful of ice cream swirl looking icons with various appearances.

You can do a few things with those imported appearances. Such as replace them on the model, and then right click in the box with those icons and say "remove all unused". Or you can be more forceful by right clicking on them and using "Unassign and Delete". 

So my thought here is that perhaps the old colors were in the model, and something "restored" them somehow when it was copied. It's not the biggest bug out there, but I'm curious about it in case something changed lately. If you can repeat it, please let me know. I'm happy to investigate this one and maybe prevent this issue in the future.

Thanks,

[mbostonsprint]

Just to follow up -- I'll send you some more info if/when I run into this again. For now, problem solved by user education....

[mbostonsprint]

Hi, Phil et al. --

I have duplicated this behavior in several ways with various sequences of copy/paste into a new design, and what I think is happening as the "symptom" is that Unassign and Delete doesn't work on the physical materials selection. At least, I see that there is no disappearance of the default Steel material property when I select the icon and perform the unassign/delete function from the right-click menu. I may be missing something here in how that should work, but I am open for any advice.

Root cause for this behavior is that indeed the default material characteristics are somehow being carried along from the original model file, and unassign and delete doesn't seem to have any effect either in the context of the full imported model file, or in the copied/pasted subassembly model file. I can unassign and delete successfully the materials properties that I assigned to the parts, though. Interestingly, when I do that, I get a second instance of the default Steel icon as a substitute.

Let me know if you want me to send you a step file of the subassy as reply to your previous email. Thanks --