From 3a4dfb92f65cd384031afbb1c2df5f1eed891d01 Mon Sep 17 00:00:00 2001
From: Andrzej Kapolka <drzej.k@gmail.com>
Date: Fri, 2 May 2014 19:37:42 -0700
Subject: [PATCH] Let's try using the neck parent rotation, rather than the
 neck, to fix separate heads.

---
 interface/src/avatar/FaceModel.cpp |  8 ++++----
 interface/src/renderer/Model.cpp   | 11 +++++++++++
 interface/src/renderer/Model.h     |  4 ++++
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/interface/src/avatar/FaceModel.cpp b/interface/src/avatar/FaceModel.cpp
index 709a9fc79d..90e596bde5 100644
--- a/interface/src/avatar/FaceModel.cpp
+++ b/interface/src/avatar/FaceModel.cpp
@@ -29,11 +29,11 @@ void FaceModel::simulate(float deltaTime, bool fullUpdate) {
         neckPosition = owningAvatar->getPosition();
     }
     setTranslation(neckPosition);
-    glm::quat neckRotation;
-    if (!owningAvatar->getSkeletonModel().getNeckRotation(neckRotation)) {
-        neckRotation = owningAvatar->getOrientation();
+    glm::quat neckParentRotation;
+    if (!owningAvatar->getSkeletonModel().getNeckParentRotation(neckParentRotation)) {
+        neckParentRotation = owningAvatar->getOrientation();
     }
-    setRotation(neckRotation);
+    setRotation(neckParentRotation);
     const float MODEL_SCALE = 0.0006f;
     setScale(glm::vec3(1.0f, 1.0f, 1.0f) * _owningHead->getScale() * MODEL_SCALE);
     
diff --git a/interface/src/renderer/Model.cpp b/interface/src/renderer/Model.cpp
index 5c06d2fcf3..a177783955 100644
--- a/interface/src/renderer/Model.cpp
+++ b/interface/src/renderer/Model.cpp
@@ -434,6 +434,17 @@ bool Model::getNeckRotation(glm::quat& neckRotation) const {
     return isActive() && getJointRotation(_geometry->getFBXGeometry().neckJointIndex, neckRotation);
 }
 
+bool Model::getNeckParentRotation(glm::quat& neckParentRotation) const {
+    if (!isActive()) {
+        return false;
+    }
+    const FBXGeometry& geometry = _geometry->getFBXGeometry();
+    if (geometry.neckJointIndex == -1) {
+        return false;
+    }
+    return getJointRotation(geometry.joints.at(geometry.neckJointIndex).parentIndex, neckParentRotation);
+}
+
 bool Model::getEyePositions(glm::vec3& firstEyePosition, glm::vec3& secondEyePosition) const {
     if (!isActive()) {
         return false;
diff --git a/interface/src/renderer/Model.h b/interface/src/renderer/Model.h
index 14589d1464..ae2bcd79b8 100644
--- a/interface/src/renderer/Model.h
+++ b/interface/src/renderer/Model.h
@@ -132,6 +132,10 @@ public:
     /// \return whether or not the neck was found
     bool getNeckRotation(glm::quat& neckRotation) const;
     
+    /// Returns the rotation of the neck joint's parent.
+    /// \return whether or not the neck was found
+    bool getNeckParentRotation(glm::quat& neckRotation) const;
+    
     /// Retrieve the positions of up to two eye meshes.
     /// \return whether or not both eye meshes were found
     bool getEyePositions(glm::vec3& firstEyePosition, glm::vec3& secondEyePosition) const;