View Full Version : Modelling Smoothing and Un-Smoothing Cylinders

2010-05-02, 15:42
Hey all.

This is a small mini-tut for mainly Chuc on some basic methods of smoothing and un-smoothing cylinders and other objects. These techniques I'm going to be showing you can be used on items like scopes to make them appear more rounded and the un-smoothing techniques can be used for optimizing models for LODs, COLs and general optimizing.

For this tutorial I'm going to be using 3DsMax9, (not 2009) with no added scripts etc but the the methods seen in this tut should work fine on later and previous versions of Max just fine.

First of all I've crated this simple 8 sided cylinder, crated with MAX's shape tools to show you the basics methods of smoothing and un-smoothing cylinders.


First I'm going to touch on Max's inbuilt smoothing features, thou this tutorial is mainly about manually smoothing objects since these features do not do what we want in this tutorial and these smoothing features are mainly used for high poly, sub-division modelling where all we want to be doing in this tutorial is slightly smoothing up low poly models in certain areas.

First of all there are two main smoothing tools in Max, MeshSmooth and TurboSmooth. These tools basically do the same thing but TurboSmooth is generally better.

If I apply the "TurboSmooth" Modifier from the modifier list to our cylinder you can see it smoothing up our cylinder all over the shot like so:

Now as you can see its also smoothing up the caps with this tool as it is which we do not want since if we did this on something like a scope it would completely mess up the scope and the rest of the model which we dont want. You can also smooth the object more by turning up the Iterations, like if I turn it up to 5 it looks like this:

Now if I delete the TurboSmooth modifier since we dont want it, there is one way we can only smooth the parts we want with turbosmooth but it also has a few problems. First I'm going to convert my cylinder to an editable poly, and select the side faces with the face selection tool, then I'm going to detach (button located to the bottom right of the 2nd pic) them to there own septate object, unselect what's left of the cylinder and then select the detached side faces and then apply the turbosmooth to that like so:

Now in the last picture this looks to archived pretty much what we want, but there is a few problems with it. First of all the main problem is that the septate cap objects of the cylinder have now not smoothed with the bulk of the cylinder and they still only have 8 sides to them, which totally defeats the point of what we want to do. We could delete the caps and recap them but there is also a more significant problem with there now being loads of un-optimized edges in the cylinder which if I collapse the turbosmooth modifier and select them you can see them clearly here:

So the turbosmooth method isn't really an option, even thou there are ways you can optimize this, TurboSmoothing is best left for high poly, subdivision modelling which is totally different from what we want to do here where we just want to smooth a low poly model a little. If you want to find out more about TurboSmoothing and how it should really be used, google Subdivision modelling, high poly modelling and next generation modelling.

Now if I undo back to the start I can show you the manual methods of smoothing I mainly want to focus in this tut.


Now first thing I want to do is convert this Cylinder into an Editable Poly. Not and Editable Mesh etc since we can only get the features we want to use in Editable Poly mode.


Now in editable poly, if we go to the edge selection mode and select all the centre edges of the cylinder. Now the simplest way to do this on a complicated model is to just select one like so, and then click the "Ring" button (located to the right of the next pic) which will then select all the edges all the way around the object next to it, providing your in editable poly mode and all of your faces are in Quads and not Tris or anything.

And we then have all the edges selected. I know you can just manually select them all very easily on this simple model, but on a much more complicated model where there are edges and faces behind the object your trying to select, this feature then becomes gold dust.

Now just to show you this can't be done on models that are in tris and if your unsure what the difference between tri and quad faces are, I'll convert this cylinder into complete tris by going "TurnToPoly" in the modifier menu and then selecting min poly size to 3 and then try and select the edges by selecting one and then clicking the Ring button, you will see nothing happens.

Now if your in the situation where your model starts off in tris, you can remove them by selecting each face in the middle of the quad and then hitting the "Remove" button to remove them like so:

And then you can select the edges by Ring again like so:

Although this may seem pointless and unnecessary, its important you have your faces in Quads to work with because otherwise you will run into lots of optimization issues later if you try the next methods I'm about to go in with your faces in tris etc.

So back to where I was with all the edges selected (also note the tris off the cap have gone, they also need to go for optimization reasons) and now I can show you how you can easily manually smooth this cylinder round the edges using the Chamfer tool.

With your edges selected round the cylinder, click the little window next to the Chamfer button, and the Chamfer edge window will pop up.

Now my Cylinder looks pretty messed up right now because the chamfer value I have on is far too large. Now its a matter of trial and error until you get the value your looking for, so with a Chamfer value of 0.1 it looks like this.

Now what we are looking for is evenly spaced edges all the way round and we can see a Chamfer value of 0.1 is a little to small, so if I increase it to a value of 0.2 it looks like this.

Which is pretty near the mark of what we are looking for so that will do for me so I'm going to hit ok and stick with it :)

Now we can see my cylinder and its caps have both been smoothed up and looks much smoother :D

But I'm not happy with it yet, I want it smoother so with all the edges selected I'm going to apply anouther chamfer with a value of 0.1

Now we can see my cylinder is really nice and smooth, but its came at a cost since my cylinder is now 124 tris where before it was only 28 tris to start with so keep in mind how many more tris your piling on when doing this.


Now say I wanted to un-smooth this cylinder because it wasn't smooth and I didn't have the "undo" feature available to me since I received the model like this to start off with. A simple way to do this is select one in every two cap edges like so all the way round:

Then with that done, hit the "Ring" button like so to select the cap edges on the other side in the same way:

Now with all of them selected, hit the "Collapse" button (in the bottom right hand corner of the next pic) and the edges you have selected will collapse into a single vert like so, leaving the cylinder with fewer faces and as such, "un-smoothing" it:


Now our cylinder is down to 60 tris from 124 tris :)
This method of un-smoothing cylinders and other objects is brilliant for optimizing models for LODs and COLs and even just when the main model has to many tris in a spot it dosen't need them :D

Now moving on from all of that I have this L85A2 here which I feel the SUSAT scope could be a little bit smoother for the 1st person model, so lets use what we have learnt on it to smooth up the scopes end :)


Now if we look at the scope close up, we can see it dosen't have that many edges and it could do with double it has now but lets do it only on the end of the scope since that is the bit closest the player and what the player sees the edges on the most, leaving the rest of the scope in the same state.


So first, lets select one of these edges around the scope and click the Ring button in order to select them all the way round :)


Now hit the Chamfer edge tool and with a value of 1 it seems to smooth it pretty nicley, but I feel a value of 0.95 is just that little bit better and then I'm going to hit Ok to apply :)


All looks good, the UVs dont look distorted at all from it luckily and the only thing that dosne't look quite right is all these unoptimized verts we have round here:

Best way to get rid of them is to target weld them one by one down onto the lower vert like so:

Now doing this has distorted the UVs on the end of the scope a little but I'll get into repairing them later on.

If we look on the other side of where we did the chamfer, we can see the verts look pretty good there but if we drag a selection box around one of them, we will find there is in fact two verts there when there should only be one:

This is just because like on the other side its crated anouther vert, just the new vert is right ontop of the other. Right now its unoptermized and the simplest way to fix it is just to select all the verts around that area, and then weld them all up using the welding tool to a very small value of 0.01, like so :)

Note the before and after values, with the before verts being 2921 and after being 2905, with meaning we have welded up 16 verts which to me sounds just right so click ok and all done, no distortion of the UVs etc there too :)


Just one thing reaming and that's to repair the UVs on the front a little, best thing to do here is select the faces around that area with the face selection tool then apply the Unwrap UVW modifier and manually repair them:

Picking the texture for the model your working on when repairing the UV helps a lot I find since you can then see what your working with, to do this simply drop down the top right hand corner dropdown list, click pick texture, select bitmap and browse to the .dds file or w/e your texture is and select it and then it should be applied as the new background image like so:

Now in the bottom left is the UVs we need to clean up a little and we can see a few verts aint quite where they should be like this vert here being much higher than the rest:


My guess by looking at the texture is that selected vert above is the only vert left in the right place and the rest of them have been lowered with the UV, so select all the lower verts and drag them up to the upper vert position.


and now if we look at the end of the scope it all looks much better now :D


Now one small little optimization we can do here, as if we look at the UV we can see lots of green edges which would suggest lots of non-welded UV verts which is not so good for performance.

If we select all the verts here, right click and his weld selected it will weld all the verts close to each other but be careful when using this tool since it can screw up your UVs if not used with care so always check afterwards its all worked ok.

and in the last pic you can see all the green lines have turned to white which is what we want and nothing has moved on the UV and the model UV's still looks good so we can see nothing was messed up there :)

And now with that small change our scope looks much, much smoother :D


Now lets un-smooth this scope for say a LOD etc, so lets first undo the smoothing what we have just done by selecting one in every two of the cap faces but making sure they are above the triangle bit like so, and then hit ring to select the other ones on the other side:

Now normally using the ring tool in this kinda situation would select all the edges all the way down the scope but because we have selected the edges above a tri face and not above a quad face, the ring tool selection was stopped at the tri which for this case is what we wanted :)

Now if we Collapse the edges we have selected we go back to what we had before, although now the UVs are a little bit distorted.

Now before we go cleaning up thous UVs I want to unsmooth our scope more than this, so again, select one in every two cap faces round the edge and then once that's done, hit the ring tool to select them all :)

Now we can see this time our edges have been selected all the way down to the end of the scope which is what we wanted here and now if we collapse these edges, the entire scope is going to be unsmoothed :D

Now you wouldn't want to look at this scope now in a 1st person model:

But this scope is now really optimized for a 3rd person LOD etc which what we are looking for here as even at a small distances, you can't tell the difference :)

And you can smooth up and un-smooth these scopes even more for what ever we want :D

I hope you have learnt a lot from this tutorial and you can use these techniques in your later work :D

2010-05-02, 16:47
Nice tutorial.

2010-05-02, 16:54
Rhino you have such patience to write down this, very nice.

One thing I think is good to tell to modelers in general is not to use prime numbers like 5, 7, 11, or its multiples to represent round things. It may be no issue for the model itself, but make impracticable most of reducing and UV techniques, I saw it in sometimes in models I took to "optimize".

Good numbers for cilinders are 24/36, so you can reduce to 12/18 for lod 1 and 6/9 for lod2 and still look round.

2010-05-02, 16:58
Heheh, you have no idea :p

I first set out last night on doing this as a Video Tutorial, I went all the way thought it pretty much fine, stopped recoding the then the fecking program wouldn't save the file, where my earlier small vid tests it saved fine. Thought it was a one off so did the entire vid tut again and then again, came to the end, went to save it and again, didn't fecking save!!! so ye then I went to bed and wrote it up by hand :p

The good thing on the other hand is I dont need to explain it to lots of people nor do I have to do the work myself :p

And ye, when making Cylinders I normally use even numbers, only use odd numbers when its a very small cylinder and its necessary for keeping the polys down, like on a 3 sided cylinder or 5 sided, sometimes even 7 but above 7 its always even numbers for me :)

2010-05-02, 17:10
As usual Rhino, you're the man. These are some nice and simple techniques, I'll definitely be using them

2010-05-02, 17:17
BloodBane611;1335717']As usual Rhino, you're the man.

I'm the man with the 27.7m e-penis? :mrgreen:


2010-05-03, 10:15
Shit, we have no more excuses to use the multires tool to produce lods...:mrgreen:

2010-05-03, 10:44
you never had en excuse to use multirez to start off with, because it just fails the models so hard (unless it is fecking 800m lod or something)

2010-05-03, 10:53
Yes, it was pretty ironical, it's the reason why I always ask my modelers to produce themselves the lods before I export the models. :-)

2010-05-03, 11:04
haha, perfect, not a fan of having to redo the lods (when i get the time) of all the weapons that we have currently. people are learning it though :D

2010-05-04, 12:07
Hey Rhino,

What happens if something like this happens?


2010-05-04, 16:25
Well first before you repair your UV you need to weld up thous unoptimized verts I can see round the chamfer area, also from the looks of things your chamfer value was too small when you did it, since you want each edge to be the same distance apart where your chamfer edges are too close, as per this part of the tut:

Now my Cylinder looks pretty messed up right now because the chamfer value I have on is far too large. Now its a matter of trial and error until you get the value your looking for, so with a Chamfer value of 0.1 it looks like this.

Now what we are looking for is evenly spaced edges all the way round and we can see a Chamfer value of 0.1 is a little to small, so if I increase it to a value of 0.2 it looks like this.

Which is pretty near the mark of what we are looking for so that will do for me so I'm going to hit ok and stick with it :)

ie, the distance between the red arrow wants to be excatly the same length (or pretty close to it) as the yellow arrow:


If its not, your cylinder will not look round and will look worse than before :p


Once you've done that then I can go into repairing that UV but you want to get the model right before you do any UVing.

2014-06-20, 09:05
The pictures of the Smoothing part have disappeared. Any chance we can bring them back ?

2014-06-20, 11:36
Nope, ImageShack takes pics offline after a time (which is one of the reasons why I stopped using them all together) and I never had them backed up. Should be able to make it out from the text however.