Interpolation for limb move cents?

[uncle808us]

Which interpolation is proper for limb movements lifting an arm bending a head etc, ease in ease out? linear? smooth? I'm confused.
Thank you for reading and any helpful advice.

[slowtiger]

For most natural movements smooth is the default and best option: everything which starts from rest and ends in rest. Once you get things going and combine different movements, see that they connect in a way that momentum is preserved, sometimes linear does the trick, but even here smooth seems to work most of the times.

Bounces and falls follow different rules. A fall is linear and stops abruptly. I've never been able to automate bounces satisfactorly, so I key them by hand, often with a drawn curve as a help (bouncing ball principle).

[uncle808us]

Thank you slowtiger
I appreciate you assistance.

[Greenlaw]

I typically just leave it set on Smooth. The effect of Smooth can be like 'easing' but it's really not the same thing. From what I've observed, Smooth is looking at how the curves move in and out of a keyframe and it will try to 'smooth' the motion without a noticeable change in speed while the character is moving. However, when the character is moving into a hold pose, it does have the effect of easing in.

I create a lot of animation for television using Moho and I find Smooth is fine for most character movements. I rely on Smooth because it lets me focus on getting good key poses for my characters and less on which keyframe interpolation mode I should be using.

That said, I don't recommend setting the default Interpolation mode to Smooth. Instead, set the default to Use Previous Key. This way, Moho just copies whatever mode you used in a previous keyframe on the channel you're editing. If it was Smooth, the new key will also be Smooth. If it was Step or Linear, Moho will use that.

Note that this doesn't mean I never use the other modes. I will use the other modes when I explicitly want a specific behavior. But, TBH, that's more rare than you might think.

Some additional tips:

1. In normal character animation, I mostly use Smooth, Cycle and Step modes. I use Linear from 'mechanical' motions where I need a constant rate.
2. When using Cycle, I like to make the first and last keyframes identical...I literally freeze the start points and just copy and paste them to the end. It's easier and so much quicker to work this way. Then, when I set the last keyframes cycle, I set it the start just after the first keyframe...this prevents the 'hiccup' that can occur because of the repeated keyframe.
3. I don't use Step that often to create a hold. Instead, I prefer to freeze the keys where I want to start the hold, and copy those keys to the frame where I want to start moving again. This has the same effect, doesn't require changing interpolation modes, and it helps me see and edit what's going on in the timeline more clearly.
4. When setting up Smart Bone Actions, I almost always use Linear inside the Action. To do this, set frame 1 of your Action keyframe to Linear. This will make it easier to set up complex animations in the Action since element is moving at the same rate during the action.

After setting frame 1 to Linear, make sure frame 0 is set to Smooth or whichever mode you intend to use during animation. If you don't set a Linear key at frame 1 of your Smart Bone Action, the action's animation can be affected by changes you might during animation, and the result can be very bad.

Don't worry that you're using Linear keys inside the Smart Bone Action; you are not locking yourself into this mode by doing this. Remember, the mode you use when animating the Smart Bone Dial while on the Mainline is what should determine the speed and interpolation of your animation. (This is why both frame zero and frame one need to be defined separately in the Smart Bone Action.)

Hope this helps.

I'm planning to make some more videos when I go on Holiday, and I'll try to make one that covers this area thoroughly.

[uncle808us]

@Greenlaw:
Thank you. I appreciate all your knowledge and the generosity you have in sharing it.