Using mirror modifier removes smoothing groups in 3DS Max 2018

[jibijib]

Using 3DS Max 2018.

If you use the mirror modifier it either removes the smoothing groups or there is an error that doesn't display them.

Is anyone else getting this?

Your post subject line has been edited by @hagen.deloss : Using mirror modifier removes smoothing groups

[jibijib]

Any details? Can I not use the mirror modifier without it a) Max applying it's own smoothing groups, b) removing all smoothing groups?

How do these things 'slip through the net' with every version? It worked in 2017 - wouldn't it be beneficial to test these functions when you work on things related to it?

Do we even have someone to replace forum mod Alfred yet?? It feels like it's best to just report bug problems by yelling them into a hole.

[hagen.deloss]

Hello @jibijib I'm Hagen, 

great to hear from you on the Forums! I'm not AJ, but I'm trying to catch up on here the best i can while still training up! i look forward to working with the community on here as much as possible in the coming months, super excited 😄

In regards to your question, I'm interested in how complex your mesh is? I wasn't able to re-produce normals not being mirrored by the mirror tool, but that's me lacking context/ not reproducing the correct environment. Are you using the mirror feature in the modifier stack, or the mirror tool that is found on the upper ribbon?

If there is any way i can take a look at your modifier stack on the mesh, or better yet take a look at your file directly, that would be awesome! You can send it to me via a private message, but no worries if confidentially is an issue. Besides reversing the normals with the normals modifier, I'm going to wait to suggest anything else until I can get some more info from you.

Please select the Accept as Solution button if my post solves your issue or answers your question.

Talk to you soon

[hagen.deloss]

@jibijib

I wanted to check back and see if my post helped you with your problem. It would be super helpful if you could add a post with how you decide to proceed, and your results. That way other Community members can benefit from your process

Please hit the Accept as Solution button if a post or posts solves your issue or answers your question.

[jibijib]

Thanks for the reply Hagen!

I'll check on the mesh I was working on, it was a 200k poly airplane seat.

[hagen.deloss]

@jibijib

oooh sounds complex, I look forward to hearing more about the project and helping out with the mirror modifier! 

I have always had good luck with the mirror tool from the ribbon and haven't used the mirror from the modifier stackwith much success. 

Hope this helps!

Please select the Accept as Solution button if my post solves your issue or answers your question.

[Diffus3d]

Hey @jibijib and @hagen.deloss!

Is it possible the seat model is from a CAD program?  If so, it's possible it has explicit normals.  In that case any modifier will break the smoothing groups.  Any chance that's what's happening?  If you test on another object do you still see the behavior?

Best Regards,

Alfred

[hagen.deloss]

Hello @jibijib

I wanted to check back and see if @Diffus3d or my posts helped you with your problem? It would be super helpful if you could add a post with how you decide to proceed, and your results. That way other Community members can benefit from your process

Please hit the Accept as Solution button if a post or posts solves your issue or answers your question.

[jibijib]

Sorry - no it didn't!

Incidentally, the original models were CAD models, but these were not used in the modelling procedure!

I've found the mirror tool in the screenshot above flips the normals, which is weird. I stopped using it a while as the modifier was a much better thing to use.

[Diffus3d]

Hi @jibijib,

Does this happen with all models or just the one you are working on?  If you break off a tiny part of it, does it still happen?  If so, can you attach a tiny part of it?  

Best Regards,

Alfred

[brieder7KWA5]

This issue is very old and still not resolved.

Symmetry modifier as well as the mirror modifier removes Smoothing Groups.

Please fix it.

Yes, it happens to all the imported models.

With the import you can keep the smoothing groups, but as it was mentioned.

Once the Symmetry or Mirror Modifier is applied, it deletes the smoothing groups.

Please add this to the top of your agenda. It should be an easy fix in the code.

It's a real bummer. In order to use a simple symmetry or mirror option, I need to use Blender, zbrush, c4d or other tools that can handle it without a problem. Exporting, Importing, dealing with other software packages, scaling issues, flipped normals, etc. And of course, the ResetX Form Modifier removes also all smoothing groups.

The problem is still evident in max2022. Thanks for fixing.