How to rig a hand.
Basically, there's two ways to go with this. 1) make a skeleton that's easy to rig, but takes longer to animate with, or 2) make a skeleton with custom controls that take a long time to set up, but is very easy to animate with. If I were rigging a character with just a few fingers, or one that was more of a secondary character without very many animations, I would use the simple rig approach. But if I were going to be doing a lot of animations with this character then I would take the time to set up a nice custom rig with all the finger controls so it could be animated without actually having to select each finger joint and rotate it manually.
Before we begin with the rigs, let's look at the actual bones of the hand...
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This is an illustration from Henry Gray's Anatomy of the Human Body. It's good to know the relative lengths and placement of the finger bones. I know you'll probably already have the hand modeled and you'll size and place the bones to fit inside the hand, but this is really good information to keep in mind even when you're modelling. The main thing to notice is the the length of the lower finger segment is about the same as the length of both upper segments put together. A lot of times people think all the finger segments are the same length because if you look at the inside of your hand they do appear to be, but that's because of the skin and fatty tissue surrounding the bones. And the third segment (the tip bone) is about half the size of the middle segment, or one third of the two together. Also, take a look at where the thumb bone attaches to the hand. It's way down by the wrist, not up by that fleshy part between the index finger and the thumb. That's where many people attach the thumb, but it's not going to move exactly right if you attach it there. |
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Technique
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Pros
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Cons
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Simple FK setup. |
• Very easy to create. | • It gets tedious manually rotating each section of each finger to pose the hands. |
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Use wiring and spinners to control the fingers. |
• Easier to animate with because all the controls are in one place. | • Takes a long time to set up, depending on how many fingers the characters has and how many segments each finger has. |
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Use Reactor Controllers and sliders to control the fingers. |
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Same as above. |
• Same as above. |