Transform Attributes

See Transform attributes.

Joint

Radius

Specifies the radius or size of individual joints.

For more information on joint radii, see Bone Radius Settings.

Degrees of Freedom

Specifies which of its local axes the joint can rotate about during inverse kinematics (IK) posing and animation. X, Y, and Z are on by default.

Stiffness

Specifies the current joint’s resistance to rotation during posing. You set stiffness for each axis (X, Y, Z) separately. For example, a wrist joint moves more freely bending toward the forearm than it does from side to side. So, you can set the Stiffness value in the plane perpendicular to the forearm (most often the Y-axis) to reduce its mobility in that plane.

Note

• For Stiffness to work properly, the joint chain needs to have more than two bones.
• IK solver calculations for Stiffness can require a little more time than they usually require, so use stiffness only when its effect really needed.
• Joint stiffness with IK is difficult to control. The current joint stiffness algorithm works like a set of springs might work on the joints. While it is easy to say how it works, it is very difficult to control.

The effect of the X, Y and Z Stiffness values is relative to the values assigned to other joints in the joint chain. For example, in a joint chain with two joints, if joint1 has a Stiffness of 1.0 and joint2 has 2.0, joint2 will be twice as stiff as joint1. With stiffness set to 0, no stiffness is specified. In general, this is the recommended setting for all of a skeleton’s joints.

Since the Stiffness values for joints are relative to the values for all the other joints in the joint chain, when you set the Stiffness for at least one of the joints, you should also set the Stiffness values for the other joints in the chain so that they do not have the default (0). For example, you might set the Stiffness values for all the joints in the chain to 1, and then set the Stiffness values for the very stiff joints to 2 (twice as stiff as the rest), or 3 (three times as stiff), and so forth. If some of the joints in the chain still have the default setting of 0, the joints may lock up during IK posing.

Preferred Angle

Specifies how an inverse kinematics joint prefers to rotate during IK posing.

The IK solver often can rotate a joint in a number of different ways in order for the last joint to reach the goal.

Depending on how you want your character to move, some rotations are more appropriate than others. You need to identify the preferred angles for your character’s actions. Two types of IK solvers, the single chain IK solver and the rotate plane IK solver, will then give those angles priority over other possible angles during joint rotation. The angles you give priority to are the preferred angles.

Joint Orient

Specifies the orientation of the joint’s local rotation axis.

Segment Scale Compensate

When this attribute is on, the joint compensates for the scaling of its parent joint, and so is not affected.

When this attribute is off, the current joint’s scaling (the Scale X, Y, and Z attribute values) is affected by the scaling of its parent joint.

Default is on.

Joint Labelling

Specifies the label settings for the current joint.

Other Type

Lets you define a custom label type for the current joint. For example, using the Other Type field you can label a dog skeleton’s tail joint as Tail(None). Only available when Type is set to Other.

WarningThe retarget solver only recognizes default label types and may not know how to properly retarget animation between joints that have custom label types. Whereas if you labeled a joint with a default label type such as Foot(Left), the retarget solver would automatically know the proper behavior for a foot (for example, it stays planted on the ground until the knee joint above it in the hierarchy moves or rotates) and would retarget the animation accordingly.

Draw Label

When on, the current joint’s label is visible in the scene view.

Joint Rotation Limit Damping

Sets the damping range for the current joint. You can set joint damping when you want a joint to slow down when it approaches its defined limits. You need at least three joints for damping to work properly.

Min Damp Range

Specifies the angles (relative to the minimum joint limit angles) at which resistance begins to occur.

Max Damp Range

Specifies the angles (relative to the maximum joint limit angles) at which resistance begins to occur.

Min Damp Strength and Max Damp Strength

Specifies the amount of increasing resistance within the Min Damp Range and the Max Damp Range. Values can range from 0, which takes the joint all the way to its limit with no resistance, to 100, which halts the joint at the outer edge of the damp range. A value of 50 would specify a gradually increasing resistance as the joint rotates past the Min Damp Range angle.