HTC Vive & Oculus Rift users- Test out VR demo from downloads:
http://badplangames.com/
Automatically constrained Arms/Hands for VR. This package doesn't just include an incredible model of realistic human arms, but an entire animation class system for picking up or using any kind of object. This makes developing for VR skip straight to the stage where you're adding what's unique to your experience. Combined with Tweening normal map for fist pose to make wrinkles way more realistic!

Features:
-Picking up
-Dropping
-Class system of object types:
-Pinch
-Point
-Hilt
-Gun
-Ball
-Claw
-Each Class has unique animations:
-hover
-grasp size
-Each Class uses different adjustable pick up requirements:
-Grab Distance
-Hold Point
-Held Position
-Held Rotation
--------------------------------------- Included sample objects:
-Left and Right Arm, Half Arm, Wrist, & Only Hand
-Backpack
-Bow & Arrow
-Burger
-Button
-Car Gear Shift
-Steering Wheel
-Simple Jeep
-Door
-Sword
-Shield
-Plank
-Phone
-Pen, Pencil, Mech. Pencil
-Desert Eagle Gun
-RPG launcher
-2 Handed Ak47 Gun
-2 Handed Gattling Gun
-2 Handed Chainsaw
-Bomb (with fuze lit animation and explosion animation)
-Office Interior
-RPG Environment
-Gun Range
-Car Highway

Summary -- Theory of FullArmsVR:

LOCK ON SNAPPING::
--Pickup--
FAVR works using a lock on system where hands will indicate the ability to pick up something by hovering over it and playing the corresponding Preparation animation such as a hand opening up to pick up a sword. Then when the user presses the trigger the object is parented to the hand either at a specific position and rotation or a dynamic one based on the acceptable pick up angle and grab distance. A specific position might be used for something like a pen that you would want to pick up into a drawing orientation. A more dynamic pick up might be used for a sword so you can pick up the sword from any side of the hilt or a spherical object that you would want to pick up from any side like an apple or snowball.

This solves the core problem with hand visuals in Virtual Reality because you want clear feedback to the user that they can pick something up, but having hand animations for every single pickupable object is a nightmare especially when trying to align it from any angle. You can use the grab distance to give the user the ability to pick up objects with bigger hitboxes making things like catching falling objects out the air suddenly much easier, but without the problem of parenting the objects too far from the hand mesh that it would look weird.

--Constrained--
We took this a step further when we realized that snapping the hand hover position to interactable virtual objects feels great for constrained objects like opening a door, pulling a lever, pressing buttons, turning a steering wheel and maybe even more importantly 2 handed weapons or objects such as large guns or swords where an object can not be parented to both hands, but both hands stay relatively connected to the object.

Both pickup and constrained objects work together to pull off incredible interactions with any kind of object.
VR CALCULATED Inverse Kinematics::

By knowing where the head and hands are at all times, we can make a very intelligent guess as to how the arms are bent and how they are rotated to feel natural to the user's arm movements and position. It's a whole new level of immersion to naturally see your entire arms performing complex actions as if they were your real arms. Getting that representation to feel right and look good connects your mind to the VR experience in a powerful way.