Modeling for animation – Body

Character modeled for animation is modeled to deform well in animation. This article desbribes benefits of edgeflow and edgeloops and the general ways to use them on a human/humanoid torso and limbs.

To begin check out  my article on surface flow, if you already haven’t.   And then, to go futher we need to understand edgeloops.  Quoting guru Bay Raitt:

An Edge Loop is an interlocking series of continuous mesh edges used to accurately control the smoothed form of an animated subdivision surface.

Edgeflow and Edgeloop are essentially the same thing.  Flow as a loop separates areas, defines shapes and directs edgeflow. You use loops in places where major deformation happens in animation.

Overall edgeflow within each looped area matters, too. Idea of a good flow, as I see it, is that when stretching or compression happens the polygons are already aligned towards the change.  Then the deformation is usually problem free.

The general advice is to model the flows following the main muscles under the skin. It can get needlessly complex considering how many mucles move a human body.  Some people have been obsessing over edgeloops for years.  Luckily you only need loops for main muscle groups or body masses.  Think what main masses/muscles move in a character and how. Direct the surface to flow along them and form loops around them.  The loops may be interlocking and that’s all good.  Then they mix and crease together better.

What if you want superb muscle definition?  Much of the missing detail can be added with displacement maps(from Zbrush, Mudbox and the like), and when the base moves correctly the displaced ‘muscles’ on it move mostly alright, too.   Though if you want realistic flexing muscles, you need a heavier setup – but this gives a good base to start from.

modeling for animation - body loops and flowsWhat are the Main Masses moving in a human/humanoid?

  • Back of a character bends below the chest.  You need loops going around the torso.  Chest bends too, even the rib cage below deforms, however the musle masses on chest and shoulder & back-area have more effect on the shape change, shoulder having clearest effect. You should have flow from chest directed to flow over the shoulder and to the back. Please note my optimization here has lead to a pole, a 6 edges intersection, in the middle of the back. It is not troubling me, but if you build similiar mesh you may want to add few polygons in that region to get rid of the pole.
  • The arm-mass connects to the shoulder and the problem area is over the arm-socket.
  • Head and neck moving about affects the area around the neck and some ways to the back.
  • Legs move the buttocks as well.   The mass movement limits to top of the hip bone, pretty much.
  • With arms and legs the problematic bits are knee and elbow both. Masses of back- and forelimb come together and separate there.  The loops help to give more mass on the outside part of the bending limb, giving material for both parts that bend away and a centerline that stays more or less in place. You may get by with a tube-like structure here for cartoon-characters where things aren’t that exact OR by having many loops that you carefully weight to bones to deform just right.

model    for animation - x-loop

Highlights and edges show the flows I like to use for this model.   Disclaimer: Please note this is definitely not the only way to do this, just A way.  You can get by with less loops, more loops or with different loops. Whatever works, works – I find these work for me.

The loops above, in limbs and at the top of the shoulder, are variations of a very useful x-loop.  See the diagram of a more complete version of it.

Also here is another version, a knee with more ‘mass’ left in.modeling  for animation - knee variation You can do varied X-loops.

Do you find this helpful?  Please let me know.  And if you don’t think the shown flows help animation, please give critique.

Read more about edgeloops here  http://web.archive.org/web/20120422232142/http://www.3darts.com.br/tutoriais/edge_loop.php. Original article has expired but can still be found in Google archive(Thanks Terry). It is in Portuguese.  Here is a translation to English.

11 Replies to “Modeling for animation – Body”

  1. Here’s another one that needs careful attention added in a video someday to our community.

    The thing is someone somewhere needs to look ahead way before the animation tools are released this way users can prepare way ahead of time so when it hits we have a jump on this by learning every thing there is to know regarding all of the things we should be aware of before taking our models into an animation package.

    I am hoping and wishing this could be you, not to put stress on you but some day , maybe because animation is such a big topic on Luxology right now and we are all waiting to see what Luxology has for us in Modo 501. As for me I have Messiah just in case we are let down by Modo 501 animation tools.

    thanks again for all your help,

    Savnac

  2. I agree this too would benefit from video form – turning the model around and showing and explaining the loops, at least.

    I hope to be a person helping people to troubleshoot things in characters or animation(production). I’ll do what I can – not much but at least something.

    By the way regardless of how much I write about meshes here, I hope someone new to animation focuses on rigging even more. If the rig sucks, no mesh deforms well. Rig is number one. Getting both the rig & mesh right is of course better.

  3. thank you, really helpful. I am new to human body modelling and very obsessed at muscles, body anatomy and edgeflows. I’ve tried to do some many times but I’m still not convinced. I’ll try your way of doing it.

    thanks

    1. Hi William and thank you. I’m happy to help. You know my way is just A way – not THE way. But then again I don’t think there is a one way that is always right. I find different shaped models I build tend to vary a lot, even the humans I make differ in their flows. But the main flow directions I show here stay pretty much the same. They do the job and, for the reasons I explain in this article, make sense.

  4. Hello Again-

    I am looking for the tips on how a character’s body should look in the wire frame for animation.

    I am almost done with a simple character but question if the body all over is correctly looped in the places where it should be.

    I see your grid graph, but there use to be more on showing examples of a full body here . Did you move it to another location.

    If so can you please point me in the direction.

    Thanks,

    Savnac

  5. Thank you very, very much for all the knowledge you are sharing with us – and for free! As a self taught wannabe CG artist, I must say it´s hard to find a place like this, in which someone teaches the actual theory of why some things work better than others, and it´s even harder to find this information for free.

    Seriously, thank you VERY much. You´re great!

    I heard somewhere that one of the best things that us begginners can do regarding edgeloops is to analyze the models of experienced artists in wireframe. I got the ones from your Files page. Is there any other source/artist you recommend?

    P.S.: Yes, the link you provided is in Portuguese. That´s my native language (which explains why this post may have some grammar errors).

    1. Thank you Zorrer. I get all warm am fuzzy feeling from reply like yours 🙂 Really it is my pleasure. Sharing knowledge has brought only good things to me, so it is Give and You Shall Receive-kind of thing we have here.

      Yes, definitely study the wireframes of professionals. Taron comes to mind first. For others I would need to dig up my old references from somewhere. Instead I recommend you browse and search for wireframes and topology references at Polycount-forum, CGsociety forum Modeling-section and elsewhere, just google the key words.

      Your English is very good, by the way.

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