Triangles vs Quads

Baj Singh

Hoy,

I've started working on a character model with the intention of getting one of the animators at work to have a crack at it.

The problem is that most characters i've built in the past have simply been posed in Zbrush without ever going into the rigging stage.

Now, ive seen a lot of debate regarding the use of edge loops, pure quads and triangles (this model from Bayonetta kicked off the issue http://www.flickr.com/photos/platinumgames/3797579510/sizes/o/ )for a game mesh and now after looking at the mesh i'm working on, i'm unsure as to how well it will animate.

In terms of tri count, I wasn't looking at any limitations as its just a bit of fun but I thought 15k would be a reasonable limitation (model currently at about 9.5k minus the duplicate foot and hand). I was just wondering whether im going the right way regarding the actual structure of the model.

Cheers.

CompanionCube

i think there was a thread just like this the other week.

remember that quads are just 2 triangles. with a deforming mesh you still have to think about which way the invisible edge in a quad is turned.

the only way to know in the end is to rig it and skin it and put it through some tests. before that just comes from experience and talking to riggers/animators about deformation and topology.

Rurouni Strife

I can't really comment on specifics about tri's and quads, but when your modeling for animation keeping everything in quad form is usually best. Quads deform nicer in organic meshes and give you less distortion.

I think your character will deform OK depending on the rig used. I can see some tri's sporadicly throughout your model. I'd try to clean it up so they are 4 sided. If you can build and weight paint a very basic skeleton to test deformations before you pass it off to your buddy you might want to try that just to see what needs extra work.

Mark Dygert

Try to keep it as cleanly quad-ed as possible it not only helps with deformation but with assigning skin weights, but don't beat yourself up about it. Anyone doing skin wieghts shouldn't complain too loudly unless there are issues like in the middle of the back, and the back of the neck.

Lately I've been painting more and more skin weights and the tris are becoming less and less of an issue but they are still annoying because they break loops or send loops off in weird directions. People who model in loop mode normally take care of those issues where vert/poly modelers normally don't care what the loops are doing.

Personally I think you could stand to lose a lot of loops. Even without the tris there are some pretty tight loops that can make deformation and weighting a pain.

I really really wish Maya would allow flipping of invisible edges, because you end up with a lot of quads that get turned into two tris just to get the tri-stripping to flow the right way, super-lame.

If you're going to work that dense you might as well keep it all quads or quad optimize loops without creating tris.


But you need to be mindful of where the poles are created and how that will effect loops.

Baj Singh

Thanks chaps,

I think i'm going to continue, making necessary modifications but keeping the essential edge loops around the major joints. I'l take a look at the loops and try and optimise some of them out but keep the majority of the tri's in areas of smaller deformation and where the poly density goes from high to low (and vice versa).

haikai

I agree with Companion Cube. It's all triangles in the end. I don't see why you wouldn't want to have explicit control over how the quad is going to be divided since the result can be different between modeling programs, software used to bake normal maps and stuff, and the game engine or middleware. For me, I try to triangulate quads that are being bow-tied and twisted, and try to predict which direction would be best for deformation in important areas. Just avoid having too many edges coming together at one point. I'm not saying you shouldn't try to use quads where possible, it's just not nearly as big of a deal on the final low poly model as it is for prepping a sculptable mesh. At least, that's how I see it.

r_fletch_r

Id try and keep it as Quad heavy a possible if your smoothing the mesh, otherwise keep the tris out of the joints. i usualy try to hide my triangles in sneaky spots no one will see and don't deform.

I think the use Quads thing is sort of blown out of proportion by folks who don't really know their shit, its like a cover all critique they can post and feel smart.

yiannisk

Vig the latest version of maya finally introduces turn\spin edge. Enjoy

r_fletch_r is pretty much on the spot and i have expressed my opinion regarding quads in that other thread.

Quads means visually cleaner mesh to work with.
it doesn't really make any other difference as most engines see triangles anyway.
http://www.capcom-central.com/concept/re4/LeonWireFrame.jpg


You can use triangles if you need them to define certain shapes better.
But overall use quads and keep it clean.
http://kingslayer.wordpress.com/2009/04/26/bayonetta-modeling-her/

Justin Meisse

if someone else has to work with your file keep things neat and clean

if it's personal use feel free to triangulate your mesh, have it's texture a 200 layer psd with 2 or 3 brush strokes on every layer and name everything untitled0xx

yiannisk

LOL justin i have once worked on someones file and i was trying to select about 500 columns to replace them with instances in a scene where every object was actually object348957346 or box243432 or line67683 there were thousands of spheres cylinders boxes and objects scary stuff. I actually made the scene from scratch by using its basic pieces. it was impossible to work with otherwise


However if you want for some reason to see your actual triangle flow do it, it might actually be helpful to arrange edge angles for specific animation deformations and then use a script that hides the middle edges afterwards before you pass it along.

tip: Preserve UV works better when in the area you are tweaking all edges are connected. The UV vertex doesn't loose it's flow (which happens sometimes otherwise). Especially in the case of T junctions.

Cheers!