¿Even or odd number of sides for your geometry?

Martin Rivas Acosta · Jul 2012

Do you prefer even or odd number of sides for your cylinders and cones?
What are the advantages you get from your choice?

I always choose even numbers because they are better for symmetry but is there any good reason to use odd number of sides?

Thanks in advance.

Selaznog · Jul 2012

Always an even number for me, unless there's some sort of special circumstance.

Jason Young · Jul 2012

I usually do even numbers, though odd is fine if it works. I find even numbered cylinders easier to tie into other pieces of geo, for example the arm into a shoulder. Like you said, you also get the benefit of symmetry. However, sometimes an odd number might be just enough to round out the silhouette and the next highest even number isn't needed/adds polys. In some cases, you might be able to start with an even number, break it down to an odd number at some point, and then back to an even if needed. Like, start with an 8 sided cylinder at the shoulder, take it down to 7 along the length of the arm, down to 6 at the wrist, etc. I don't typically do that, but it could optimize things a bit if you really needed to get the tri count down. Just an example any way.

McGreed · Jul 2012

Yeah, it depends on the model, like if you doing a wheel, or a propel, you might want to make 1/3 of it and then copy it, to get some repeating UV and such, without being too noticeable.
But otherwise, yeah I always stick with even, because often you have two or more sides with is the same and its much easier to symmetry it.

EarthQuake · Jul 2012

Even numbers, and more specifically easily divisible(by 2, but better by 4) numbers make for much easier LODS

Consider:
32, 16, 8, 4

30, 15, 7.5, 3.25

25, 12.5, 6.25, 3.125

24, 12, 6, 3

So yeah, 64, 48, 32, 24, 16, 12, 8 and 6 are what I generally use for cylinders. If you've ever done any LODs you'll know how annoying it is to work with 15, 7, etc.

But not even for LODs, just general optimization. Say you need to get your tri count down on an asset, its really easy to drop a 16 sided cylinder to 12(edge collapse) or 8(remove every other edge), but working with weird numbers like 15, 13, 7 etc you have to remodel it or do it in a slower way.

Odd numbers also make uv seam placement less convenient, and mirroring difficult. I can't really think of any benefit to using odd numbers.

Martin Rivas Acosta · Jul 2012

Thank you all for your answers. I knew about the advantages when collapsing edges but I never thought about LODs (I haven't worked with those yet).
I guess I'll keep working mostly with even numbers as I have done since the beginning.

Mark Dygert · Jul 2012

I agree with EQ, and stick to easily divisable by 2, not really because of LODs but because I'm never really sure if I'll need to drop or add some edges on the cylinders later on.

Even numbers make it easier to use things like "Dot Loop" to select every other edge in a loop and collapse to cut your cylinder from 16 to 8. This gets weird with odd numbers.

There is even a special mode Dot Loop Cylinder" for working with the end caps of cylinders, which max handles in weird ways, but this gets around that.

The only real time you would probably use odd numbers is if the object calls for it specifically, like a room that has 9 sides and it must be recreated faithfully...

Xenobond · Jul 2012

EarthQuake wrote: »

Even numbers, and more specifically easily divisible(by 2, but better by 4) numbers make for much easier LODS

This. It also makes life less annoying for others that might have to work from your files. Also fits in with making sure to have mirrored elements be centered properly.

AlecMoody · Jul 2012

EarthQuake wrote: »

Even numbers, and more specifically easily divisible(by 2, but better by 4) numbers make for much easier LODS

Consider:
32, 16, 8, 4

30, 15, 7.5, 3.25

25, 12.5, 6.25, 3.125

24, 12, 6, 3

So yeah, 64, 48, 32, 24, 16, 12, 8 and 6 are what I generally use for cylinders. If you've ever done any LODs you'll know how annoying it is to work with 15, 7, etc.

But not even for LODs, just general optimization. Say you need to get your tri count down on an asset, its really easy to drop a 16 sided cylinder to 12(edge collapse) or 8(remove every other edge), but working with weird numbers like 15, 13, 7 etc you have to remodel it or do it in a slower way.

Odd numbers also make uv seam placement less convenient, and mirroring difficult. I can't really think of any benefit to using odd numbers.

I do the same thing- multiples of 4. Also, depending on what you are modeling, it can be helpful to use multiples of 4 for the sub-d cage.

Danielmn · Jul 2012

earth quake: good point I never thought about the LOD

yeah I go with even for symmetry and most because easy to collapse sides into quad for your topo ..........when I can

¿Even or odd number of sides for your geometry?

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