From 49c835b6fc72707cedc9c8a66708daaeabe28a95 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Sat, 4 Jun 2016 20:53:30 -0700
Subject: [PATCH] use camera twist for walk steering

---
 interface/src/avatar/MyAvatar.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 6fdcd8f797..ca9bbec6ff 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -1214,7 +1214,10 @@ void MyAvatar::updateMotors() {
         if (_characterController.getState() == CharacterController::State::Hover) {
             motorRotation = getHead()->getCameraOrientation();
         } else {
-            motorRotation = getOrientation();
+            // non-hovering = walking: follow camera twist about vertical but not lift
+            // so we decompose camera's rotation and store the twist part in motorRotation
+            glm::quat liftRotation;
+            swingTwistDecomposition(getHead()->getCameraOrientation(), getHead()->getUpDirection(), liftRotation, motorRotation);
         }
         const float DEFAULT_MOTOR_TIMESCALE = 0.2f;
         const float INVALID_MOTOR_TIMESCALE = 1.0e6f;