To Quad or Not To Quad

# 1 24-02-2010 , 02:05 AM

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This question begin to roam its way into my head via CT bram's question about modeling a gold ball, and Nitroliq's response that included a tutorial.
(thread can be found here

I know there are two different camps in maya, those whom believe in the bible of the all powerful Quad edged polygon ( I myself am mostly in this camp) and those who do not. That being said i suppose you could poke every ace on that after the second extrude, then delete every other edge on each face and you'd end up with quads, but I'm not going to take the time do do that 276, or 423 times.

I guess what i am getting at with this, is, When would you say its ok to deviate from the quad ( tris for game models obviously do not count in that question ) for a poly model?

I personally do not like to deviate from quads unless i just have to, and there are very very very few times when i do 'just have to' you get more predictability out of quads, for everything form Smoothing to animation so.

Also, a question i have had for a while is. Why is it that only the Maya users, or only work flows that require maya down the line, require Quads? is this a maya specific requirement and i just don't realize it because i am strictly a maya person?
or are other tutorial makers, just...oblivious to the correct way to do things? for other apps i mean.

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# 2 24-02-2010 , 04:31 AM

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I always say that you don't need just quads ever. That having been said, sometimes if you use irregular shapes (tris, n-gons) you can end up with smoothing errors if you take it down that route.
Also, if the model is rigged, you may get weirder deformation at joints and stuff.

Trial and error is really the key for figuring out which to use.

I tend to stay to quads, but only because I am OCD and I like the aesthetics of having a nice orderly mesh.

And generally, modelers like to keep mostly quads regardless of which program you are using; it is by no means specifically a Mayan problem.

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# 3 24-02-2010 , 05:24 AM

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I have seen alot of both 3ds and Modo tutorials that there are plenty of n-gons in, (5,6,7 or even 8 sided). I've also heard some people state that they had to redo a model to remove the n-gons because they were going to be using it in Maya later on and didn't know it at the time.

I stay with quads to the point that even end caps on cylinders, i will poke and delete the appropriate edges to turn them into quads.

I know and understand the in-s and outs of quads vs n-gons, I'm just curious of other peoples opinions who might use other soft wares more regularly then i do.
Plus i know alot of the new modelers always ask this question, and was hoping that this might be a good thread for them to get the explanation they need for that issue from more then one point of view.

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# 4 24-02-2010 , 05:36 AM

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Like I said, Maya isn't any more Quad-exclusive than any other program. I don't know why people would convert to quads to bring it to Maya, but I don't think they need to. My guess is they don't use Maya enough to know it doesn't need all quads, or something along those lines.

I used to use lots of N-gons, but then I realized they screw up how the model displays sometimes, so I stopped. Maybe 3DsMax and Modo don't display the models with Ngons the way Maya does (i.e. Maya tessellates everything to be tris, at least in its own mind, so as such it creates edges in an N-gon which may change the form of the ngon in 3D space, if that makes sense. I posted an example to demonstrate. There is not a physical edge there, but Maya makes one.)

But I THINK most programs do that as a rule.

Sorry, also, if none of that made sense; I had no idea how to phrase it.

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# 5 24-02-2010 , 10:13 AM

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I think the problem with using n-gons in maya is the fact that because it tessellates to tris at render time you have no control on which direction it will split the ngon as so its hit and miss if you will get a display error or if animating a deformation error.With this in mind is a better practice in general to try to stick to quads but the odd tri doesnt usually matter especially if not in and important area.
I try to use quads all the time simply because its good practice for when i have to and i dont want to slip into lazy modelling ..hehe

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# 6 24-02-2010 , 10:25 AM

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I had a tank I wanted to import from lightwave, this would not import because maya only likes 4 sided polys when importing.......dave

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# 7 24-02-2010 , 12:54 PM

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Dave, there must have been some other reason it would not import; Maya can full-well import non-quads. However, if you exported from Lightwave, there certainly could have been settings in the exporter that prevented Maya from importing. Format depending, of course, Importing/exporting can have many different issues.

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# 8 24-02-2010 , 01:25 PM

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I just think quads deform better. Triangles can cause unwanted pinching or dimpling in something like hi-res facial modeling. Also, if z-brush is in your work flow, it likes quads...doesn't take to tris or n-gons well.

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# 9 24-02-2010 , 01:29 PM

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Hi Joopson
I did look into it maya has a number of issue with mesh and names, I must say the mesh I was going to import was messy was going to clean it up in maya...........dave

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# 10 24-02-2010 , 05:56 PM

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One minor point that may or may not be maya specific, is when using the insert edge loop tool, quads are necessary for the edge loop to be created fully. Quads probably make it easier to determine how the topology is flowing while modelling.

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# 11 24-02-2010 , 06:05 PM

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Ive not had a problem with importing any mesh with tris, quats or Ngons in Maya.

I go the quad route, it keeps the mesh nice and flowing as well as allowing it to have a Z tickle with no probs!

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# 12 24-02-2010 , 09:38 PM

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Should have said,

"To Quad or Not To Quad...

That is the question"

"No pressure, no diamonds" Thomas Carlyle

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# 13 24-02-2010 , 11:52 PM

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Swert:
when using the insert edge loop tool that is exactally correct, If a poly isnt a quar, then maya cannot decide which of the opposing edges you want the edge to go to, so it just has a brain fart and dies, only splitting most of the way around the polygon.

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# 14 25-02-2010 , 05:14 AM

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This is a topic that is difficult or impossible to get a straight answer.

I have found that people are in two camps and you are not easily going to convince either side to budge on their position.

I can vouch the the quad issue does seem to present more of a "problem" for maya then other applications as although I am not a professional modeler I can claim that I am a hard core tutorial watcher and I have seen enough lightwave, modo, 3ds max, and xsi tutorials to assure you that the worry about making every single polygon 4-sided is not stressed nearly as much in other packages as it is in Maya.

I can also refer to a quote from the guy that modeled the stargate universe ship in lightwave that there were many ngons in his finished model and the only hitch in the pipeline is when they had to work on a portion of the model in maya those ngons caused maya to puke where lightwave handled them just fine. You can find it by a few simple googles of lightwave and SGU.

My own philosophy is to strive to make my models as quad centric as possible. However, I am not going to increase the number of polygons in a model by a factor of 4 to simply convert one triangle that in most cases will not be seen into a quad. The same goes for the occasional ngon (usually at the cap of a cylinder). In most cases I poke or split the face to be quads or tri's but for something that is going to have a procedural texture applied and is not going to deform I am not going to blows hours of time trying to retopologize an entire model to make a face that either will rarely be seen or renders just fine into all quads.

A quote from a master modeler at pixar that switched form Maya to Modo was interviewed by luxologies Brad Pebler and when asked the question about ngons after showing some hardsurface work in modo that clearly had ngons replied -

Whether or not I use ngons depends on the pipeline rules set by the vfx director and studio I am working for AT THE TIME. As long as I am not mandated to use all quads, as long as the model looks good in the final shot I am not going to lose any sleep over the occasional tri or ngon.

This is a philosophy that I agree with. Shoot for quads but don't waste time or polygons or both trying to make everything 100% quads. Take the simple golf ball example in a thread I started. The only method I found online for doing this in maya produces an object with over 300 faces that have 5 sides! When rendered it looks just fine, with a procedural texture there are no render artifacts and I was able to uv map it and apply a distortion free logo on the ball as well.

Why would I spend the time trying to covert 300 pentagons into quads and tris only to get a worse looking render? Furthermore, I have seen no one suggest a solution that produces an all quad solution. One of my gripes about the folks that are the first to bitch about a tri or ngons rarely ever suggest a solution. I can promise in EVERY model I produce if there is a tri or an ngon there is a REASON that it is there. Either trying to change it adds unnecessary geometry, unwanted creases, or in some cases actually produeces an effect I want.

What gets me upset about the "all quad natzi's" is that they set an arbitrary inflexible rule. Then rather the suggest a solution they imply you are a "hack" modeler if you have a tri or ngon in your model and should be branded on the forehead and band from using Maya and delegated to serving coffee to the true righteous worshipers of the all mighty QUAD.

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Last edited by ctbram; 25-02-2010 at 10:32 PM.

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# 15 25-02-2010 , 06:45 AM

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I will say that, Most if not all, even I myself who subscribe to the all quad religion of Computer graphic arts, will say that the occasional tri or poly -Normally- causes no problem, unless they are constricted by a work flow that required there to be Quads only.

I will also say from experience that in MOST cases having a model turn out that is 100% or even 99.99999% quads is always based upon the first few edits to the primitive, or plan, or what ever beginning surface you used. If you start it out properly form the get go, and you think ahead two or three steps with every piece of detail you wish to add, then you will have a all quad model in the end, or...at least a damn near all quad model anyway.

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