SubDiv Model Disappears with "boxmod" Material

[valentino.rajan]

Hello! I am currently modelling in Alias Autostudio 2021 with SubDiv, and I am running into a serious problem. I have an object in my file that shows with the "usetex" shader, but disappears with "boxmod." In addition, the hull around my object will not return when I use "Controls ON" to reinstate the CV's, and edges. Given these conditions, I am no longer able to edit my object even though I was not finished. As far as I can tell, this problem began when I attempted to bevel an edge loop, and I have not managed to resolve it since. I have included two images: Capture1 and Capture2. In Capture1, you will see that the main body of my car is visible with the "usetex" shader. Capture2, however, shows that when I attempt to use the "boxmod" shader, the main body of the car disappears. Please help!! Thank you in advance for any assistance!

(P.S. I have already restarted my computer multiple times, and have exported the file as a .obj and reimported it to no avail, so I'm assuming it's a bug in the new software or an issue with my settings.) 

[stephan.pfoertner]

That is an interesting behavior - and I can imagine an annoying one.

I would love to say 'just press this button'. However, no one reported something like this before, so we will need to investigate. You can check, whether it is your preferences by just renaming the folders in C:\Users\your_username\AppData\Roaming\Autodesk\Alias - Please close Alias before renaming the folders. This will start Alias with completely clean preferences. If it doesn't help, you can return to their original name.

A few questions trying to narrow down the problem:
- When you tried to export an OBJ, you probably used 'File > Export > Active as Subdiv...' right?
What did it do? Did it fail, or did it write a file?
- What version are you working with? 2021, 2021.1, 2021.2, or 2021.2.1?
- Are you allowed to provide me the file?

[valentino.rajan]

Hello! Thank you for your response. I have changed the Folders' names as
you've instructed and nothing has changed unfortunately.

With regard to your exporting question: yes, that's what I did. It
successfully wrote a .obj file, and I even imported it into Maya to test
whether it kept all of the original file's data, and it appears as expected
in Maya; however, when I import it back into Alias, it does not appear
anywhere in the viewport, and it does not appear in the Object Lister
either. I am currently working on Alias 2021, so I anticipate this might be
a bug that still needs to be fixed by the Autodesk team.

Yes I will provide the file!

[valentino.rajan]

I have uploaded a zip folder with both the .obj and the .wire files.

[valentino.rajan]

I apologize for not clarifying earlier, I am running Alias 2021.2.1

[stephan.pfoertner]

Thanks for the files.

First of all: nice car!

Now the bad news: I digged into it, and there is nothing wrong with the file, it is absolutely sane. But all subdivs in the file have been converted to normal nurbs surfaces for some reason. Once Subdivs are converted to nurbs, there is no automated way back.

If I am not mistaken, there are only a few ways that would convert a subdiv to a nurbs:
- Use the 'Surface From Subdiv' tool and switch off 'Keep originals'
- Pick all surfaces, 'Copy&Paste', and then delete the wrong group
- Load & Modify & Store the file in an older Alias Version that didn't support subdivs

Not sure, maybe there are more ways that I don't think of right now.

The interesting thing is: Even those parts that have been a subdiv in your screenshot 'Capture2.png' are now converted to nurbs in the file that you provided. Can you remember any steps you did inbetween your first post in this forum and now, that could have caused this?

I know, that you don't want to hear this, but there is nothing that we can do, to get your data back. The only thing that we can do, is to find out the cause, so it won't happen again.
If I would be you, I would take a strong coffee and tryout the Retopo Tool: Pick a group node in your file and start the Retopo Tool. Using the Middle Mouse Button, you can insert and extrude edge loops very quickly on the given surfaces. Modeling is much quick that way. Using the built in 'Relax' and 'Edge Flow' you should be able to retopologize that car in about 2 hours. I am feeling with you - it is always hard to loose work.

[valentino.rajan]

First of all: thank you very much!:)

I very much appreciate all of your attempts to find a solution. I still have a lot more detailed work that I needed to do to complete my model, so I think I will try the retop tool, but ultimately I will have to start over and find a way to ensure this doesn't happen again by saving multiple versions in separate files as I work along. Thank you again for all of your work, looks like I will just be getting more practice with SubDiv!