Splits mouse rotation from IA_Turn to avoid snap turn on CAVE

Closes #656

Source/RWTHVRToolkit/Private/Pawn/Navigation/CollisionHandlingMovement.cpp

@@ -41,8 +41,11 @@ void UCollisionHandlingMovement::TickComponent(float DeltaTime, enum ELevelTick
 	{
 		// you are only allowed to move horizontally in NAV_WALK
 		// everything else will be handled by stepping-up/gravity
-		// so remove Z component for the input vector of the UFloatingPawnMovement
-		InputVector.Z = 0.0f;
+		// so rotate the input vector onto horizontal plane
+		const FRotator InputRot = FRotator(InputVector.Rotation());
+		const FRotator InputYaw = FRotator(0, InputRot.Yaw, 0);
+		InputVector = InputRot.UnrotateVector(InputVector);
+		InputVector = InputYaw.RotateVector(InputVector);
 		ConsumeInputVector();
 		AddInputVector(InputVector);
 	}
@@ -67,13 +70,8 @@ void UCollisionHandlingMovement::TickComponent(float DeltaTime, enum ELevelTick
 			}
 		}
 
-		// in case we are in a collision and collision checks are temporarily deactivated, we only allow physical
-		// movement without any checks, otherwise check collision during physical movement
-		if (bCollisionChecksTemporarilyDeactivated)
-		{
-			ConsumeInputVector();
-		}
-		else
+		// in case we are in a collision and collision checks are temporarily deactivated.
+		if (!bCollisionChecksTemporarilyDeactivated)
 		{
 			// so we add stepping-up (for both walk and fly)
 			// and gravity for walking only