Skin does not update normals

benjamin4MQAH
Advocate

Skin does not update normals

benjamin4MQAH
Advocate
Advocate

Hello.

 

I'm not sure if the bug reporting system actually works so I'm going to see if there's a solution here.

 

The issue is that normals are not updated in the viewport after deformation by Skin modifier - it is also an issue in renders but can be solved by either adding a Edit Normals after Skin (or any modifier that recalculates normals).

I'm not seeing any settings for normals in the Skin modifier

 

Un-deformed:

benjamin4MQAH_0-1695714563167.png

Deformed:

benjamin4MQAH_1-1695714578320.png

After adding Edit Normals:

benjamin4MQAH_2-1695714596607.png

 

 

 

0 Likes
Reply
869 Views
9 Replies
Replies (9)

dmitriy.shpilevoy
Collaborator
Collaborator

Maybe the model itself is "broken" and skin just makes it evident. I have similar problems with explicit normals that are stuck and don't update when I edit an element for example.

When you rotate the head using vertex/edge/face selection on a model without skin, does it behave the same or normals are fine and work as expected?

 

0 Likes

benjamin4MQAH
Advocate
Advocate

I've tried resetting normals using Edit Normals and Reset XForm (+ collapse) but the result is the same. I get a similar problem if I animate some vertices. It looks like Max is caching some normals and not updating them when using skin or animating vertices. Animating a modifier (like Twist has no issues).

 

 

0 Likes

dmitriy.shpilevoy
Collaborator
Collaborator

Try to clean it through OBJ export-import and then skin wrap.

0 Likes

benjamin4MQAH
Advocate
Advocate
Sure, but the video above is a standard sphere primitive and that at least should be "clean" 😉
0 Likes

dmitriy.shpilevoy
Collaborator
Collaborator
Ah, true. Had a brainfart moment here.
Welp, I would still try the usual tambourine dance for the lack of better solution: cleaning through OBJ, converting to mesh and back to poly, restarting max, restarting PC, exiting and entering apartment again etc.
0 Likes

domo.spaji
Advisor
Advisor

@dmitriy.shpilevoy wrote:
... cleaning through OBJ...

 

That is the best way to screw normals, actually the only way I know that can (and will) do it is importing normals with OBJ.

Other "usual" things have same effect as exiting and entering apartment.

0 Likes

domo.spaji
Advisor
Advisor

That is problem in your (probably newer/st) Max version, don't remember ever seen it.

 

Few years ago I would be surprised by the lack of user responses  on things like that.

Still dont understand that, but not surprised😁

0 Likes

benjamin4MQAH
Advocate
Advocate

Hmm, problem exists in 2023 and 2022 as well.

It seems that every time you switch view mode (Standard <-> Performance), the normals are cached at that frame and never updated. I can move the time slider and switch modes and I get normals from that "state" of the mesh. (Still just testing on primitives).

 

Wondering if it's a driver issue. I'm on a nVidia card using Studio Driver 536.99. Maybe someone with a AMD card can try and reproduce? Will update drivers and see if that helps.

0 Likes

domo.spaji
Advisor
Advisor

I didn't go further than 2021 (and decided to stay on 2015).

There is that problem in 2021, but only when animating on editable poly.

Didnt notice before because I don't do (literally)  anything on that base level.

No probs with editable mesh, edit poly, skin and in render (scanline).

 

It's not the driver.

0 Likes