Why should i use Gimmick Joints and dont go straight to Blendshapes?
Im a Modeler so i would just use Blendshapes.
In wich case are Gimmick joints the better solution?
I assume a combo of both would give me the beste result?
Hi again @oglu
Some people like some techniques better than others. Both comes with good and bad things.
I always go to blendshapes because I think you can achieve more detailed deformation (and anatomy preservation of the asset characteristics) when sculpting shapes than with joints but I have been proven otherwise in the past… I just prefer blend shapes because if you want to achieve the same level of details on complex assets with just joint base things you end up compexifying the rigs.
That been said you need to know that the issue with blendshapes is as well how things get driven and how sculpts combine themselves. RBF driven nodes are not always understood by riggers and same goes for cone base ones because sometimes riggers themselves fail miserably explaining them.
The only constructive advise I have on this is for you to handle this with a technique you feel comfortable with but be sure you understand all the implications of your choice.
Myself I only use joints base corrections in situations where I can’t drive the correction with a single transform/joint.
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Hi Jerome that is great info.
I will go with Blendshapes first.
gimmick joints (intermediate joints) is a very old technique (before dual quartenion exists) to preserve volume and getting good deformation around a pivot…
the advantage is, that you dont have to provide for every rotation axis a blendshape with driven keys, wich when it comes to gimbal can be very painfull to fix…
(i.e. in shoulder area you could make for every loop a gimmick-joint with distributed weights to get a nice smooth deformation…also helpfull in ellbow, hip, knee areas or spine…)
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@Oglu, just adding to what @Jerome said, for some cases using gimmick joints will be the right thing to do. For example, in our case, where we have one mesh and hundreds of possible garments, it’s faster to project and clean the skinCluster than projecting and cleaning corrective blendshapes in all the garments.
As an example, at Disney we used a combination of skinCluster + wires + cluster + driven keys as a basic layer of deformation, and we added blendshapes on top (sometimes, ridiculous amounts) to have a better control of how things look. Also, remember that when you model shapes for a character you not only think in terms of appeal or volumes, but also about motion: you can have a beautiful shape as a final result, but if the interpolation between the rest pose and that shape, or the rest of the shapes and that one, is terrible, you are going to have a bad time dealing with the whole system.
Like anything, the more practice, the better results!
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Thanks for the detailed info. The part with the practice is the main problem. I have zero.
Hello, @iker.mozos! I’m wondering if this setup of skinCluster+wires+cluster+driven keys might work well for my crowd setup. I have about 10 human characters with quite a few variations in clothing. Would you be able to explain in further detail? I’ve been stuck in BlendShape purgatory for days now…
If gimmick joints are a better bet, I’ll look into including those in the rig and skinning rather than this meticulous geo sculpting for each article of clothing in a myriad of angles.
@Totheroo, please note that I was talking about two different things: one, what you quote (skin + wires + cluster, etc), which is the way characters worked at Disney. The other one is what I discussed about using skincluster instead of shapes if you have a huge amount of clothing variety for the same body.
For the first one, we did project shapes from body to garments, but it was a tedious process, even though some tools were written to assist on that. For the second one, we only deform the bodies using skinCluster. If those shapes you are adding are to keep volume on certain poses, you can use additional/gimmick joints on the body rig instead, driving their transforms using RBF (which is something I did not mention before).
When projecting skins from body to garments, you might have to do some cleanup, and even though is not as precise as shape sculpting, for certain cases it should be enough.
Also, if you want to stick to shapes, you might want to look into SHAPES, by BraveRabbit.com. I don’t remember if it came with a defined process for that, but I wouldn’t be surprised if it did.
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