From 69dd4ff59bfa90b545657331a36e4f9923893cda Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Wed, 5 Jun 2013 13:08:17 -0700
Subject: [PATCH] Improved rotation computation.

---
 interface/src/Avatar.cpp   | 4 +++-
 interface/src/Skeleton.cpp | 4 +++-
 interface/src/Skeleton.h   | 2 +-
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/interface/src/Avatar.cpp b/interface/src/Avatar.cpp
index d8178ca643..ed4102f522 100644
--- a/interface/src/Avatar.cpp
+++ b/interface/src/Avatar.cpp
@@ -1082,7 +1082,9 @@ void Avatar::updateBodyBalls(float deltaTime) {
         if (_skeleton.joint[b].parent == AVATAR_JOINT_NULL || length < SMALL_SPRING_LENGTH) {
             _bodyBall[b].rotation = orientation * _skeleton.joint[_bodyBall[b].parentJoint].absoluteBindPoseRotation;
         } else {
-            _bodyBall[b].rotation = rotationBetween(jointDirection, springVector) * orientation;
+            glm::vec3 parentDirection = _bodyBall[ _skeleton.joint[b].parent ].rotation * JOINT_DIRECTION;
+            _bodyBall[b].rotation = rotationBetween(parentDirection, springVector) *
+                _bodyBall[ _skeleton.joint[b].parent ].rotation;
         }
     }
 }
diff --git a/interface/src/Skeleton.cpp b/interface/src/Skeleton.cpp
index b3720c8869..92dba252a1 100644
--- a/interface/src/Skeleton.cpp
+++ b/interface/src/Skeleton.cpp
@@ -118,7 +118,9 @@ void Skeleton::initialize() {
         } else {
             joint[b].absoluteBindPosePosition = joint[ joint[b].parent ].absoluteBindPosePosition +
                 joint[b].bindPosePosition;
-            joint[b].absoluteBindPoseRotation = rotationBetween(JOINT_DIRECTION, joint[b].bindPosePosition);
+            glm::vec3 parentDirection = joint[ joint[b].parent ].absoluteBindPoseRotation * JOINT_DIRECTION;
+            joint[b].absoluteBindPoseRotation = rotationBetween(parentDirection, joint[b].bindPosePosition) *
+                joint[ joint[b].parent ].absoluteBindPoseRotation;
         }
     }
 }
diff --git a/interface/src/Skeleton.h b/interface/src/Skeleton.h
index b5a7cee0ba..e98c2e7b12 100644
--- a/interface/src/Skeleton.h
+++ b/interface/src/Skeleton.h
@@ -42,7 +42,7 @@ enum AvatarJointID
     NUM_AVATAR_JOINTS
 };
 
-const glm::vec3 JOINT_DIRECTION = glm::vec3(1.0f, 0.0f, 0.0f);
+const glm::vec3 JOINT_DIRECTION = glm::vec3(0.0f, 1.0f, 0.0f);
 
 class Skeleton {
 public: