When animating characters with FBIK, the joint labelling and naming conventions provide names for the following types of joints:
Base joints are the main joints in your character’s skeleton that are required for FBIK to function. The base joints in your character’s skeletons include: Hips (pelvis or root), Spine, Head (top of neck), UpLeg (hips), Leg (knees), Foot (ankles), Arm (shoulders), ForeArm (elbows), and Hand (wrists).
Roll joints are optional joints with no real anatomical equivalents that let you create realistic twisting motions in the limbs of your characters. When labelling or renaming roll joints, give them the same labels or names as their parent joints. The roll joints in your character’s skeletons include: ArmRoll (between the shoulders and elbows), ForeArmRoll (between elbows and wrists), UpLegRoll (between hips and knees), and LegRoll (between knees and ankles).
Auxiliary joints are optional joints that serve specific purposes that may not be needed for all characters. The auxiliary joints in your character’s skeletons include: Neck, Shoulder (collar bone), fingers, toes, InHand/InFoot (metacarpal/metatarsal) and FingerBase/ToeBase (carpal/tarsal) joints.
In your character’s hands there are two specialized auxiliary joint types: FingerBase and InHand. FingerBase is most often used in quadruped hands to aid in paw/hoof placement. When you apply FBIK to your character, an effector named FingerBaseEff is created for your FingerBase joints. InHand joints are used to group each fingers’ joints. If you use InHand, you must also use the FingerBase joint as an intermediary between your InHand joints and the LeftHand/RightHand (wrist) joints. FingerBase and InHand are not needed to animate your character’s hands and fingers. However, when using hand floor contacts, FingerBase is required if you want your hands to bend at the bases of their fingers when they come in contact with the floor.
In your character’s feet there are two specialized auxiliary joint types: ToeBase and InFoot. ToeBase is most often used in quadruped feet to aid in paw/hoof placement. When you apply FBIK to your character, an effector named ToeBaseEff is created for your ToeBase joints. For biped characters, you can use ToeBaseEff with Floor Contacts (similar to the way you can use auxiliary pivots) to create good bends at the base of your character’s toes when animating foot rolls with FBIK. InFoot joints are used to group each toes’ joints. If you use InFoot, you must also use the ToeBase joints as intermediaries between the InFoot and Foot joints in your character’s feet. ToeBase and InFoot are not needed to animate your character’s feet and toes. However, when using foot floor contacts, ToeBase is required if you want your feet to bend at the bases of their toes (balls of feet) when they come in contact with the floor.
You can split the translation and rotation of your character’s pelvis between two different joints by specifying a HipsTranslation joint in addition to the Hips joint. When you then apply FBIK to your character, an effector named HipsEff is created for your Hips joint, but an effector is not created for HipsTranslation. By default, the HipsTranslation joint will control the translation of your character’s hips and the Hips joint and effector will control the rotation of your character’s hips. The HipsTranslation joint must be placed above the Hips joint in your character’s joint hierarchy and it must also be at the same position as the Hips joint in the scene view.
Accessory or additional joints
Accessory joints are the joints in your character’s skeletons that you do not want to include in the FBIK solution because they are only used for skinning purposes, for example, chest or rib joints and the joint at the top of your character’s head. Additional joints are the joints in your character’s skeletons for which FBIK joint labels or names do not exist, for example, wing or tail joints. For these types of joints, you would use the None joint label or joint names that are not recognized by the hikSolver. For information on how to label or rename these joints, see Other body parts.
