VR Hand Animation Instance

Description

VR Hand Animation Instance class is a child of the animation instance class. Animation blueprints can be inherited from it. This class must be used for VR Hand animation and should be applied to FakeHandMesh and RealHandMesh components in VR Hand inherited blueprint(Otherwise it will crash)(See VR Hand Class).

Variables

• FFingerCurls CurrentFingerCurls - Current curls of each finger from the motion controller.

• FFingerCurls FingerCurls - Curls of each finger with smooth transition.

• float GripThumb, GripIndex, GripMiddle, GripRing, GripPinky - Grip values for IK(Values from 0 to 1).

• float IndexPushInst - Trigger button push value(from 0 to 1).

• float HammerPushInst - Thumb button push value(from 0 to 1). This parameter can be used in pistols/revolvers to pull the hammer.

• float HandOrientationZ - This is a varialble which contains a orientation value(from 0 to 1). If hand faces X,Y or Z direction value will be 1.

• FVector OriginThumb, OriginIndex, OriginMiddle, OriginRing, OriginPinky - These are varialbles which contain origin locations for location based IK(Optional IK Method).

• FVector TargetThumb, TargetIndex, TargetMiddle, TargetRing, TargetPinky - These are varialbles which contain taget locations for location based IK(Optional IK Method).

• bool ProceduralSkeletonEnabled  - This is a variable which contains whether or not  procedural skeleton is enabled(Outdated and will be removed in the future).

• bool bHasWeapon - This is a variable which indicates whether or not hand has a weapon.

• bool bA_Pressed - This is a variable which indicates whether or not A button was pressed on the controller.

• bool bB_Pressed  - This is a variable which indicates whether or not B button was pressed on the controller.

• bool bTrackpad_Touch - This is a variable which indicates whether or not Traskpad was touched on the controller.

• bool bWantsToGrab - This is a variable which indicates whether or not hand wants to grab something.

• EAnimationType AnimType - This is a variable which indicates hand animation type(See VR Variables).

• EPickUpAnimations PickUpAnimation - This is a variable which indicates hand grab animation(See VR Variables).

• bool bIsGrabbed - This is a variable which indicates whether or not hand is grabbing the object.

• UAnimSequence * GrabAnimation - This is a variable which contains a grab animation from grabbed object.

• UAnimSequence* TriggerPressedAnimation - This is a variable which contains a trigger pressed animation from grabbed object.

• UAnimSequence* APressedAnimation - This is a variable which contains a A pressed animation from grabbed object. 

• UAnimSequence* BPressedAnimation - This is a variable which contains a B pressed animation from grabbed object. 

• EControllerHand Hand - This is a variable which indicates hand.

• EGrip_Code CurrentGripState - This is a variable which indicates hand grip state.

Animation Blueprint Example

Algorithm overview

Examaple hand animation blueprint contains State machine, Base animation section, Animation based IK section, Idle Pose section and Position Base IK(Optional IK Method).

Base Animations

Base Animations contains 3 cached poses(Open, Stratched and Cloused). They are used in other sections.

Idle Pose

Idle Pose section blends hand orientation(HandOrientationZ) with stratched pose. Then output blends with closed hand cache by finger curls(Make sure there are right bone names according to the skeleton).

Animation Based IK

Animation Based IK contains blend per bone for each finger(Make sure there are right bone names according to the skeleton). Blend uses Grip variables (GripThumb, GripIndex, GripMiddle, GripRing, GripPinky). Output goes to the cached pose.

Position Based IK (Optional)

Animation Based IK contains two bone IK nodes(Make sure there are right bone names according to the skeleton) for each finger.

State machine

State machine contains 3 states: Idle, Grip IK and Animation Grip.

Idle state

Idle state contains blends if player wants to grip. If player press the grip button and move the hand close to the object it will predict the pose(Rotate fingers a bit).

Grip IK

Grip IK contains Animation Based IK cache.

Animation Grip

Animation Grip has animation state machine in which are two conditions: Prop Unique and Weapon or Equipment. In the Prop Unique this an animation variable. In the Weapon or Equipment there are blends and animation variables for Grab, Trigger button press, A/B button press etc.