Ideal Bone Angle Constraints

[vivekchakraverty]

Hello All,

I was thinking that it would be really helpful for newbie animators if there was a stated desirable bone constraints of all the human joints in the front, 3/4th and side views. I dont know that much about animation but maybe someone could chip in, it need not be perfect but rather the usual angles used.

[Greenlaw]

I never use Bone Angle constraints for character joints. IMO, they are too...well...constraining. It's better to allow the joints to move freely to get the most expressive performance from a character. Using constraints in a 2D character's joints is likely to make them appear mechanical.

This isn't to say I never use Angle Constraints. In fact, I use them all the time to limit the turning range of Smart Bone Dials for controlling animation or to create mechanical rigs. I just don't like to use them in a character's joints (elbow, knee, wrist, ankle, etc.)

I might use them when rigging a robot's joints...but probably not.

If you're finding it difficult to pose a character without using constraints, the problem might be in how you are rotating the joints. For example, if you're using the Manipulate Bones tool and posing the character using only IK, then yes, that can get uncontrollable and chaotic.

The trick is to be aware that Manipluate Bones has two modes for posing a character: IK and FK. Use IK mode (the regular mode,) when you need to affect multiple bones at once, and switch to FK mode (by holding down Alt) to make adjustments to a single bone in a chain. When I'm using Manipulate Bones to animate a character, I'm switching between these modes frequently.

I wish Manipulate Bones had a third mode, one for moving a bone's position. For this, I need to temporarily switch to Transform Bone, and immediately switch back to Manipulate Bones to continue. Fortunately, switching tools is simply a matter of tapping T (for Transform) and Z (for Manipulate Bones.) (I'm not sure why Z is for Manipulate Bones but the letter Z does resemble a jointed limb, like a leg.)

But it would be better if I could stay with one tool when posing a character. (Note to developers: Thanks for any consideration of this request.)

When animating a character, it also helps to block out the key poses first. This stage in animation is commonly called Layout or Blocking. Make sure the Default Interpolation is set to Use Previous Key. Then keyframe the character at frame 1 and set Interpolation type for the keys to Step. Now, when you animate, create only key poses with an occasional in-between pose as needed. In this stage, you're only concerned with getting strong poses and timing. When this looks good on playback, select the Step keys and turn them into Smooth keys. From here, turning this into finished animation can be much easier; typically, it's a matter of copying and pasting some of the key poses to create holds so the character isn't constantly moving and drifting.

To see this process in action, please check out this tutorial video I posted recently: Let's Make A Cartoon! Admittedly, this tutorial is broad in scope, but I'll be making tutorials to cover each stage in more detail. In the meantime, this video may give you some ideas for how to pose and animate a character.

Good luck, and have fun!

[Greenlaw]

Some tips for setting up joints: On frame 0, give your elbow and knee joints a slight bend in the preferred bending direction. This informs Moho which way IK should bend the joint. You don't need to bend the artwork, just the bones, and the bend can be very slight.

In some situations, you may want to change the direction during animation (another reason to avoid angle constraints.) To do this, just set a keyframe to give the joint a bend in the other direction. Now, the IK will bend it in the other direction.

I'll demonstrate this technique in an upcoming video.

[vivekchakraverty]

Thanks a lot for your inputs!