Harmony allows you to set a minimum and maximum angle constraint on certain joints, such as the knees or elbows. When using the Inverse Kinematics tool or even the Forward Kinematics (Transform tool), it is possible that some joints will bend in the wrong direction.
If you plan to animate a lot with the Inverse Kinematics tool, it's a good idea to try the angle constraints. The angle constraints can be set by the character builder or by the animator in particular scenes where it's needed.
It is recommended to use the minimum and maximum angles only if the character does not change view within the same layers. For example, if a character is facing the camera and has some angle limitations enabled, it could be problematic if the character switches to side or quarter view since the joints won't bend the same way.
Use the minimum and maximum angle constraints if your character's views are in different templates or layers. If the character's views are in the same layers, then it's better not to use the angle constraints.
- In the Tools toolbar, select the Inverse Kinematics tool or press Shift + I.
- In the Tool Properties view, in the Mode section, make sure the Edit Min/Max Angle Mode is enabled.
- In the Camera view, Ctrl + click (Windows/Linux) or ⌘ + click (Mac OS X) on the piece to set the minimum and maximum angle.
- In the Tool Properties view, in the Selection section, click the Enable Min/Max Angle option.
- In the Camera view, rotate the Minimum and Maximum handles to set the angle.
- Test the angles using the IK Manipulation mode.
- For additional control over the Min/Max Angle, go to Edit > Preferences (Windows/Linux) or Stage > Preferences (Mac OS X). Select the Camera tab. In the Inverse Kinematics section, look at the Min/Max Angle Constraint Weight. Although the maximum value goes up to 1.0, in a production setting, the most practical value would be closer to 0.1. This value acts similar to the Stiffness setting in the Tool Properties view. The higher the value, the more difficult it becomes to approach the minimum and maximum values.