This is an issue that troubled me since I started doing animations. I could say I’m fairly good with animating characters at this day, and properly adding details and bone rotations to keyframes. But no matter how good the keyframes are, there’s always something missing which doesn’t seem possible to solve by simply inserting the right bone rotations: The life factor.
Let’s consider I’m animating a character extending its hand, holding it up for a second, then lowering it down. Normally it’s easy: At frame 0 the hand is resting, at frames 30 and 60 it’s extended, and at frame 90 it’s rested again… with potential small details in between. Yet if I extend my hand and hold it up in real life, I notice there are a lot of subtle movements. Such as my hand not having a perfect trajectory, my hand constantly shaking to some extent, and my fingers constantly changing position no matter how still I try to hold them.
Most of those details are indeed possible to add as in-between keyframes, and I already do that best I can. But after trying hard to get them right, I came to the conclusion that simply rotating bones (or using AutoIK) cannot simulate the correct movement of a body to such detail. The way the fingers and hand shake is very small and precise in reality, and attempting to keyframe that will yield some partly gibberish and absurd movement.
This doesn’t apply only to the hand and fingers. Consider yourself sitting on a chair for several seconds: There’s no way that parts of your body won’t move, slip, or shake. An extremely good animator might be able to do this convincingly via keyframes… but from experience I’m pretty sure most OK animators would have a hard time. Not to mention the excruciating amount of work it would take to simulate the exact shaking of every noticeable muscle on someone’s body, even for a few seconds animation.
Are there any tips on how to add lifelike details to animations, seemingly undoable via keyframes? Perhaps an addon or trick to automatically construct and insert movement errors in animations?
I can offer a method myself, though from what I tested so far it works rather poorly: Using a noise modifier on such bones. I suspect that adding a noise curve to the X rotation of a finger can somewhat estimate the lifelike shaking. But to properly achieve such detail, more than that is needed… and the noise curve might have to be added to more obvious bones such as the head. What are your suggestions?