New Feature: VRTK_ObjectLerp (lerp an VRTK_InteractableObject on grab).

Overview

General idea is to add new functionality that smoothly animates an object into position when you grab it. This will be an optional / extra script that you can attach to an VRTK_InteractableObject, providing a slightly different mechanic and visual from the existing immediate grab.

Code In-progress

• Created a new script class called VRTK_ObjectLerp that smoothly handles the lerp position and rotation of an object over time.
• You can attach this script to an VRTK_InteractableObject, which then will set itself up to use the VRTK_ObjectLerp.
• When an object is grabbed by VRTK_InteractGrab this class checks on the grabbing VRTK_InteractableObject to see if there is a valid / configured VRTK_ObjectLerp available, and if the object is set to lerpTransformOnGrab.
• If the VRTK_InteractableObject is setup to lerp on grab, then rather than complete the grab as normal, the VRTK_InteractGrab method calls back to a new method on the VRTK_InteractableObject that will start the lerp to position, i.e. StartLerpTransformOnGrab.
• The VRTK_InteractableObject will then call the VRTK_ObjectLerp to start a coroutine for the lerp to position, i.e. DoObjectTranslation.

Not yet done, to be confirmed:

• Once the DoObjectTranslation method completes, callback / notify the VRTK_InteractableObject that it's done.
• The VRTK_InteractableObject then calls the VRTK_InteractGrab script to grab the object again. Only this time it will tell the VRTK_InteractGrab somehow that we don't need to lerp, just do a normal / immediate grab.

Other things to consider, as per our chat on Slack:

• What to do if the object is ungrabbed mid-way, before completion: : Move the object back to the start position. : Or if it's pass the half way point complete the lerp. : Or just drop the object where it is. : Perhaps a combination, could have settings to specificy what you want to happen.
• From @bddckr: "Should work with every grab mechanic, but I think currently some of these things take at least 1 frame, so would be visible. Maybe instantiate a temporary copy and turn of visibility and collisions etc.": : Not sure I understand what this is referencing yet.. perhaps I'll see this issue once the base code I've explained above is working.