feat(Locomotion): add falling deceleration to MoveInPlace

The MoveInPlace script now has a separate deceleration setting for when
the player is falling giving a more refined feel to falling off ledges
and not abruptly slowing down.

Assets/VRTK/Scripts/Locomotion/VRTK_MoveInPlace.cs

@@ -58,6 +58,8 @@ public enum DirectionalMethod
         public float maxSpeed = 4;
         [Tooltip("The speed in which the play area slows down to a complete stop when the user is no longer pressing the engage button. This deceleration effect can ease any motion sickness that may be suffered.")]
         public float deceleration = 0.1f;
+        [Tooltip("The speed in which the play area slows down to a complete stop when the user is falling.")]
+        public float fallingDeceleration = 0.01f;
         [Tooltip("How the user's movement direction will be determined.  The Gaze method tends to lead to the least motion sickness.  Smart decoupling is still a Work In Progress.")]
         public DirectionalMethod directionMethod = DirectionalMethod.Gaze;
         [Tooltip("The degree threshold that all tracked objects (controllers, headset) must be within to change direction when using the Smart Decoupling Direction Method.")]
@@ -290,7 +292,7 @@ protected virtual void FixedUpdate()
             }
             else if (currentSpeed > 0f)
             {
-                currentSpeed -= deceleration;
+                currentSpeed -= (currentlyFalling ? fallingDeceleration : deceleration);
             }
             else
             {

DOCUMENTATION.md

@@ -1107,6 +1107,7 @@ Move In Place allows the user to move the play area by calculating the y-movemen
  * **Speed Scale:** Lower to decrease speed, raise to increase.
  * **Max Speed:** The max speed the user can move in game units. (If 0 or less, max speed is uncapped)
  * **Deceleration:** The speed in which the play area slows down to a complete stop when the user is no longer pressing the engage button. This deceleration effect can ease any motion sickness that may be suffered.
+ * **Falling Deceleration:** The speed in which the play area slows down to a complete stop when the user is falling.
  * **Direction Method:** How the user's movement direction will be determined.  The Gaze method tends to lead to the least motion sickness.  Smart decoupling is still a Work In Progress.
  * **Smart Decouple Threshold:** The degree threshold that all tracked objects (controllers, headset) must be within to change direction when using the Smart Decoupling Direction Method.
  * **Sensitivity:** The maximum amount of movement required to register in the virtual world.  Decreasing this will increase acceleration, and vice versa.