How to fix weird shading in 3ds max while modeling a gun

MujtabaYousuf

hey guys. How are you all?
Well I am modeling a stock for my ak-47 and a weird shading problem appeared. Here are the snapshots.

1- This is how it looks after applying smoothing groups.

2- This is the wireframe. 

3-) This is what it looks like after applying turbo smooth. 

gnoop

For subdivisions like turbo smooth  it should have extra loops and  quads based mesh mostly.    

For in   game model   it's all in vertex normals handling.

The easiest way is to bring it to Blender  and use weighted normals modifier there with "keep sharp" checkbox checked in, It usually  fixes all such issues evrywhere at once  whatever 'wrong" you may think your mesh triangulation is.    

  Or if  weighted normals aren't  working    then  "data transfer" modifier to copy vertex normals vectors from a copy of same object without the hole.

Surely MAx should have some 3d party plugins too.  Years ago I did it with Normal  theft . 

But a good idea also is avoiding those tiny narrow long triangles  especially non co-planar ones where weighted normals may still  be not working.   

Edited normals is always a solution but may create  you extra puzzles when you start to do lods

srsface

You should look at tutorials about good topology for subdivision. The following thread is worth reading and studying the examples posted by people, there are lots of helpful images:

https://polycount.com/discussion/56014/how-the-f-do-i-model-this-reply-for-help-with-specific-shapes-post-attempt-before-asking#latest

The latest version of Max also has a built-in weighted normals modifier, which is worth a try for fixing the shading like suggested above. That won't help with subdivision though. TurboSmooth needs good base topology to work with.

poopipe

You don't need to go to blender, just set smoothing groups 

Mehran Khan

max 2020 also has a weighted normals modifier.
also that topology is very wrong. If this is a highpoly for games than just use booleans to drill that in.

gnoop

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poopipe said:

You don't need to go to blender, just set smoothing groups 

My 3d max skills are  getting rusty  every next day  but from what I remember  getting a perfect shading on a low poly cylindrical form with such a hole is  never  working with smoothing groups only.   Without  lots of redundant extra loops  at least.  

   Well, it doesn't work with weighted normals  too actually  , I was too quick to suggest.        But projecting vertex normals  with   Data transfer in Blender   always works just fine.   My guess it's same in Maya with attribute transfer  but I never did it there.

sacboi

@MujtabaYousuf are you following a Tim Bergholz AK-47 tute?

...if so, then not only is that specific low poly region triangulated wrong but also as poopipe had mentioned, smoothing group, as well.

poopipe

Gnoop is correct, you wont get good shading with that topology unless you project normals. The fans are what's causing the surface to look lumpy

The question to ask is this..

Why are there so few segments around the cylinder if you need so many to define the shape of the hole?

MujtabaYousuf

Hey everyone. I know this is late but I have progressed after seeing the replies here. You all are awesome. 


Thanks @gnoop and everyone for crtitiques. 
@sacboi yes I was following chamferzone tutorial, I did it correct. Though it still has one little problem but it is far better than before and weird shading is gone.
Thank you all.

sacboi

@MujtabaYousuf Just keep in mind, at this initial stage when blocking out your low poly, slight shading artifacts aren't that much of a problem so try not to re-edit until 'perfect' because typically most errors are caught when finalizing the high poly mesh. I think from memory Tim also goes over this in depth plus I suggest checking out our subd thread as well, tons of relevant modeling info on 'how to' and 'why' something is done.  

EDIT:
note, was working with max 2016 at the time, that had an annoying habit of breaking my assigned smoothing groups which then required re-instating them repeatedly  : /

MujtabaYousuf

sacboi said:

@MujtabaYousuf Just keep in mind, at this initial stage when blocking out your low poly, slight shading artifacts aren't that much of a problem so try not to re-edit until 'perfect' because typically most errors are caught when finalizing the high poly mesh. I think from memory Tim also goes over this in depth plus I suggest checking out our subd thread as well, tons of relevant modeling info on 'how to' and 'why' something is done.  

EDIT:
note, was working with max 2016 at the time, that had an annoying habit of breaking my assigned smoothing groups which then required re-instating them repeatedly  : /

@sacboi Thanks man. I am a Keep working on it until it is perfect type of person. XD but yeah you are right. I will check out subd thread too. I didnt got your edit part btw. 

GARYOSAVAN

This one is also a good solution.

https://www.youtube.com/watch?v=bXeLU6hXcsM