(Solved) Reducing Cylinder Sides? (3ds Max)

Geosmith

Hello.
I'm wondering if anyone has figured out of some relatively simple way of reducing cylinder sides within Max? Specifically after the mesh has already been modelled and unwrapped, for things like LODs. Reducing by half is often too much of a reduction, and taking sides out one by one can mess with UVs and such if you then re-position the edges to make it a smooth cylinder again. 

This is something I come across very often, any insight or ideas is much appreciated. 

Geosmith

This is for LODs, not after LODs. I'm not sure of any way of reducing a cylinder in a smooth way, as from what I know the automated ways of making LODs just get rid of/weld vertices (that's a very simplified explanation), and the results don't look like a lowpoly cylinder, but more of something long and weird. 
Imagine a case where you need to remove just a few edges, but that means you have to adjust the UVs and re-regularise the cylinder which can be time consuming. 

Geosmith

Alright. As an example, bullet casings. I'd like to make two LODs + LOD0, so for LOD2 I can cut the sides in half easily, but for LOD1 I can't think of anything that's not time consuming. Each casing is also at a random angle, which I can't access because it's all a single object so no cloning one casing (unless there's a non-time consuming way). 
LOD0 is 14 sides each. 

Geosmith

In all my years of modelling I've legitimately never seen the Preserve UVs checkbox. This makes the process of manually removing edges much more bearable.
If anyone has any better methods, please do still share.

Geosmith

That's very helpful, thank you! I wouldn't have thought of using a helper.
I'm not sure what you mean by the 1-sided part though? 

Geosmith

Ah, makes sense. Thanks!

gnoop

You could try Blender as a secondary tool. It has a few extra options beyond what MAx offers.  For example it could turn top of a cylinder back to  perfect shape  with selecting top vertexes and hit "space" in loop tools.    MAx doesn't consider them a loop for some uncertain reason  with a same named tool.    Unfortunately in both  Max and Blender "preserv UV" wouldn't work  in that case .  But in Blender I am getting almost perfect fix with  http://blenderaddonlist.blogspot.ru/2013/11/addon-smooth-selected-uv.html  addon  with just a little bit rotation afterward.

In general I found Blender is better working  with  "preserve UV" option than Max.   In Blender  It's "correct UVs" checkboxes.    Wth edge sliding (double G hit)  for example  and many other mesh editing tools .   You could slide UV seam edge there   while MAx  still does  UV artifacts sometimes.    Same with edge chamfer. etc.     Even Blender "Decimate"  modifier  with UVs button on   sometimes  works better than Max  Multi-res one. 

As a last resort you could project UVs back from lod1 to lod2, lod3 etc. with projection modifier    The feature first appeared in MAx actually  , decade ago,  and only few years later in Maya as "attribute transfer" .     Blender also has it but it's still unreliable there.

Geosmith

I doubt I'll go learn how to use blender in my current position, but when I have more time I do see the benefit. Max has scripts including regularizer which can convert both edges and faces into a perfect circle. 
I do notice the ugly distortions of the preserve UVs in Max, but it seems like I can combat these by adding new edges, moving them where I want and removing the old ones. Pretty tedious, but results are acceptable. 

cptSwing

siks said:

Each casing is also at a random angle, which I can't access because it's all a single object so no cloning one casing (unless there's a non-time consuming way).

You could explode the combined meshes into it's elements via script, and use - for example - Instance Tool from scriptspot to turn the bullets into instances. Great timesaver when it works.