Designing a mesh to animate well.
Community Forums/Showcase/Designing a mesh to animate well.
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| What are the basic rules for forming joints in a mesh? I'm fleshing out concept work but need to know what has to be done to make a model usable. |
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| you'd be much better off asking a question like this on CGChat or some other modeling forum. http://www.cgchat.com/forum/ |
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| Basically make sure there is geometry running perpendicular to the direction of bend. For example, to bend the leg at the knee make sure there are rings of edges around the leg at the knee. A lot of beginners try to reduce polygon count by having long polygons which stretch the length of the limb; while this may look fine for a static model, this won't work if the model is to be animated. |
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| so a few well placed rings at bends? Sounds like what I assumed really. |
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| It's working out which vertices go with which joint that gets me. |
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| "Sounds like what I assumed really." It is fairly intuitive but surprisingly easy to forget. For example, a lot of beginning animators fail to take into account how facial muscles move when they model characters' heads. You want the geometry laying in concentric rings, as opposed to a regular grid, around the eyes and mouth since that is how the eye and mouth muscles contract. |
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| Thanks for the input jhocking. I'm still stimped when it comes to modellinga head :). I'll practice tonight. |
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| @Rottbott: Think of the "bone" that the joint moves. For example, a hip joint would control the vertices to the femur/thigh. So you would assign the Verts of the thigh (from hip to knee) to the hip joint. Likewise, the knee joint would control from the knee, all the way down the shin, to the ankle. Some of the tricky parts are around the areas of secondary movement (the butt cheeks, and around the upper shoulders) when you don't have weighted vertices to affect them. |
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| I can't even model an arse properly so "secondary movement" there is no problem :D I understand what you say about them controlling the vertices that lie along their bone, but what about the vertices around the joint itself? Which joint should "own" the vertices that surround the knee joint? The knee, or the hip? Or half and half? |
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| i just wish we had weighted bones. it would make things alot easier for me atleast. i just cant seem to make any realistic movements on my alien model, there is always some vertices that get alil too funky compared to the others |
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| What is vertex weighting ? |
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| What is vertex weighting ? To say that a vertex is "weighted" with respect to a Bone means that the vertex will move as the Bone is rotated in order to stay aligned with it. At 100 percent weighting, the vertex follows the Bone rigidly. At 50 percent weighting, the vertex moves only half as much as the Bone does. http://webreference.com/3d/lesson98/ ...Which means that when two bones meet there is bunch of vertices in that area that should belong to both bones and move so too. Otherwise you get nasty looking shears in the joints because neighbour vertices can belong only one bone (like in the Blitz3D now). Weighting lets each vertex move more freely, ie "stretch". |
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| Gotcha, I want that! Would be very helpful. |
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| Sorry it took so long to get back and answer your question Rottbott: @ RottBott but what about the vertices around the joint itself? Which joint should "own" the vertices that surround the knee joint? The knee, or the hip? Or half and half? Generally, I use a 3 ring joint setup (one ring of verts above, one at, and one below the joint). For most of my models the ring closest to the body I assign to the proximal joint (the hip or shoulder depending on which extremity you're working on). The remainder go to the distal joint (the knee or elbow). Of course this may not always work depending on how you design your model. Sometimes you have to play with it, but it's a relatively easy thing to reassign the vertices to another joint. @Dev: I'm still stimped when it comes to modellinga head :). I just sent you a head to play with ;-) |
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| Oops wrong thread. Don't mind me. |
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| OK NTense, thanks. I'll try doing that on my next modelling attempt :-) |
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