Quads and Tris and some other things.
polycounter lvl 17
Heya,
So far I've been told by teacher(s) to keep things in quads and try to never get things in tris. I've been doing some reading into this to see WHY and all I can muster is that it's better for deforming geometry (faces) and meshsmoothing.
This is all fine and dandy, but I find it hard to keep EVERYTHING in quads when trying to get mechanical details in (like cylinders popping out/in out of a face and more intricate curves and grooving). Is there a better way to approach getting such details? I'm looking into SUBDs for getting that level of detail but right now I'm using polygonal models for most of my stuff.
Right now my basic approach is to go low poly on everything and start dropping in loops with Maya's Split Edge Ring Tools to reinforce edges. This works great, but it does result in a messy mesh, and in some cases it gives me hard edges after smoothing where I don't want to unless I tweak it by hand. Sometimes I use bevelling, but it seems to give me triangles (and some wacky things have happened with more intricate grooves).
Any recommendations for better approaches into mechanical/hard surfaces?
Thanks!
So far I've been told by teacher(s) to keep things in quads and try to never get things in tris. I've been doing some reading into this to see WHY and all I can muster is that it's better for deforming geometry (faces) and meshsmoothing.
This is all fine and dandy, but I find it hard to keep EVERYTHING in quads when trying to get mechanical details in (like cylinders popping out/in out of a face and more intricate curves and grooving). Is there a better way to approach getting such details? I'm looking into SUBDs for getting that level of detail but right now I'm using polygonal models for most of my stuff.
Right now my basic approach is to go low poly on everything and start dropping in loops with Maya's Split Edge Ring Tools to reinforce edges. This works great, but it does result in a messy mesh, and in some cases it gives me hard edges after smoothing where I don't want to unless I tweak it by hand. Sometimes I use bevelling, but it seems to give me triangles (and some wacky things have happened with more intricate grooves).
Any recommendations for better approaches into mechanical/hard surfaces?
Thanks!
Replies
There's some interesting info on this topic there - mainly check out StrangeFate's posts, he makes a lot of good points.
I'd say only worry about all quads if it's around an area that's gonna deform heavily (faces, joints).
Also it's useful to keep quads because it makes it easier to select edge loops and rings which can speed up the process early on.
If the model is purely for rendering, or is never going to move/deform (such as a pistol), don't bother worrying about quads as long as the subdivided mesh looks right.
Bear in mind that using triangles/n-gons in some locations can cause the smoothing to look odd, so keep quads over big changes in angle on the control mesh.
Sometimes when you get stuck in an "all quads" mindset, you end up making wasteful game meshes. Also that can waste time when highpoly modelling, just trying to fix up tiny areas so they're all quads, when the end result won't even be noticeably different.
I'm going to try out that example you made in the old thread and see how it works although I could have sworn that I tried a similiar thing and ended up with nastiness after hitting smooth in Maya.
I'm going to take a closer look at StrangeFate's wire later this evening too and see if I can produce something like that.
If I'm making a game-res model, I tend to triangulate everything (unless it's gonna be 5k+ triangles), just so that it's the most optimised and efficient mesh possible.
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Mop is under the (mistaken) impression that you cannot optimize the triangles of a mesh unless they're clearly visible.
The end result is all that matters, like Mop said, getting into the OMG MUST HAVE 100% ALL QUADS OR I'LL CUT MY THROAT, is a bad mindset. make sure to have a good workflow, but in the end realize everything is a triangle to the engine, and you can sometimes keep a much better poly count with some triangles present in areas. Quads do have benefits, but you learn where and when they're necessary in a model, and when you get easily get away with triangles. Mostly they are in those "transition" areas that become troublesome to film modelers, because they have to pull out fancy tricks to resolve the meshflow. In games, however, we can easily collapse an edge to resolve an area that starts to get too dense.
Mop is under the (mistaken) impression that you cannot optimize the triangles of a mesh unless they're clearly visible.
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Nah, I know you can do that.
I should have made it clearer, this is just what I personally like to do - I don't like having to go into Edit Triangulation mode every time I want to see where all the edges are going.
I wouldn't do it with a mesh I had to pass on to other artists at a company, for instance - this is just for personal stuff, the way I like to work. IMHO it's good practise. I don't find it slower than quad modelling either.
The end result is all that matters, like Mop said, getting into the OMG MUST HAVE 100% ALL QUADS OR I'LL CUT MY THROAT, is a bad mindset. make sure to have a good workflow, but in the end realize everything is a triangle to the engine, and you can sometimes keep a much better poly count with some triangles present in areas.
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Well I was referring to hi-poly techniques that wouldn't be going in-game (I guess for normal maps). I've just been having a harder time getting mesh smooth to behave on most objects that aren't mostly in quads.
BTW very important aspect is the amount of edges that end up in the same vertex, if there are too many it can end up as a nasty artefact kind of thing.
For both game and nongame models I think that having clever loops is important (and I am not referring to the OMG100%QUADS thing here either, I mean, loops where needed) for both UVs and animations :
Having corresponding UV verts on the same horzontal is extremely handy to avoid annoying texture seams ; Also, animators will love you if tube-like shapes are made out of clean loops as it helps better and easier skinning.
But besides that, triangles are still cool.
The thing with subdivision is that the subdivided mesh touches your lowpoly cage in the center of each polygon. If a quad is triangulated the mesh will have to touch it in two places rather than one.
I see some very clean meshes coming from Strangefate when working : http://www.strangefate.com/webby/modeling-SubD2.jpg
Now after reading the thread a few times I'm not sure what's going on at the bottom picture. I'm assuming that TAB in LW the same as smooth in Maya (for you Maya users) or meshsmooth in Max - I hope I'm right. But after trying out MoP's example and hitting smooth in Maya I wince.
www.dustglove.com/images/notcool.JPG
What am I missing here? Is this just how Maya rolls?
edge loops to keep straight and hard edges. Take a look here on this head modelling tutorial:
http://www.secondreality.ch/tutorials/modelling/head/head4.html
On point 22) the author create these close edge loops to
sharpen the form of the eyes. He says:
"note: the narrower two edges are the sharper a crease you will get when smoothed. This is very
helpful to create bevels or corners and get away from that typical subdivision "molten wax look""
www.dustglove.com/images/notcool.JPG
What am I missing here? Is this just how Maya rolls?
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On the lower model where you have smooth - poly - sub-d you just have to add more subd iterations, see if it will look like smooth after that.
Anyways you just have to get the hang of it, subd is very logical algorythm and after some usage you should get fairly good idea of whats gonna happen and why.
On the lower model where you have smooth - poly - sub-d you just have to add more subd iterations, see if it will look like smooth after that.
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Hm, I think this is where I'm getting confused with terminologies. This is my convert to sub-d options menu :
And this is the result :
http://www.dustglove.com/images/subdobj.jpg
So I'm assuming the smoothed the object was the right way to go here.
Also If you have badly placed tris when exporting to zbrush, these areas will smooth badly, forming a visible 'nipple'.
My general advice is to use your common sense over it. whatever works for you is the best way to go
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On the lower model where you have smooth - poly - sub-d you just have to add more subd iterations, see if it will look like smooth after that.
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Hm, I think this is where I'm getting confused with terminologies. This is my convert to sub-d options menu :
And this is the result :
http://www.dustglove.com/images/subdobj.jpg
So I'm assuming the smoothed the object was the right way to go here.
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This menu looks scary, in max you can just crank the iterations and there is no confusing mess like that
yeah I wonder If you are perhaps getting a little confused with your terminologies. You understand the difference between polygon>smooth and converting polys to subD's right? The first is simply subdividing a polygon mesh, the second is converting to a true Subdivision surface.
If you've just polysmoothed your model, click on the history node for the smooth in your channel box, there are a whole bunch of options in there. Look for 'Divisions' and you can crank up from 1.
If however, you've converted to SubD, then do as Whargoul says. keys 1>3 display the subdivision model at different levels of detail, in the same way as Nurbs.
Daz / Warghoul - Do you know what the Subdivision level option under the polySmoothFace history node in the channel box is? I can change Divisions around fine but that doesn't seem to do anything.
Divisions. Up that no. and you'll most definitely be doing something
Ya know, I'm really not sure. Can't seem to get it to do anything.
I tend to model in mostly quads initially for subdivision purposes before bringing a model into Zbrush. After creating the high poly model, I'll optimize my low poly and end up with triangles all over. I do like to keep quads around the mouth loops for facial animation though. Everywhere else is fair game for tris though.