From a1b54945d6d707d243291c91133bd9b235b597fa Mon Sep 17 00:00:00 2001
From: "Anthony J. Thibault" <tony@highfidelity.io>
Date: Fri, 2 Oct 2015 10:34:34 -0700
Subject: [PATCH] Compute the model offset in the rig, using the bind pose of
 the hips.

---
 interface/src/avatar/SkeletonModel.cpp | 3 +++
 libraries/animation/src/Rig.cpp        | 9 +++++++++
 libraries/animation/src/Rig.h          | 2 ++
 3 files changed, 14 insertions(+)

diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index beb58e746c..16a6fa0531 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -246,6 +246,9 @@ void SkeletonModel::simulate(float deltaTime, bool fullUpdate) {
     Hand* hand = _owningAvatar->getHand();
     hand->getLeftRightPalmIndices(leftPalmIndex, rightPalmIndex);
 
+    // let rig compute the model offset
+    setOffset(_rig->getModelOffset());
+
     // Don't Relax toward hand positions when in animGraph mode.
     if (!_rig->getEnableAnimGraph()) {
         const float HAND_RESTORATION_RATE = 0.25f;
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index e83a63e329..25c10d7a61 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -1263,3 +1263,12 @@ void Rig::initAnimGraph(const QUrl& url, const FBXGeometry& fbxGeometry) {
         qCCritical(animation) << "Error loading" << url.toDisplayString() << "code = " << error << "str =" << str;
     });
 }
+
+glm::vec3 Rig::getModelOffset() const {
+    if (_animSkeleton && _rootJointIndex >= 0) {
+        return -_animSkeleton->getAbsoluteBindPose(_rootJointIndex).trans;
+    } else {
+        const glm::vec3 DEFAULT_MODEL_OFFSET(0.0f, 0.0f, 0.0f);
+        return DEFAULT_MODEL_OFFSET;
+    }
+}
diff --git a/libraries/animation/src/Rig.h b/libraries/animation/src/Rig.h
index c99db65081..c57b4f629f 100644
--- a/libraries/animation/src/Rig.h
+++ b/libraries/animation/src/Rig.h
@@ -204,6 +204,8 @@ public:
     AnimSkeleton::ConstPointer getAnimSkeleton() const { return _animSkeleton; }
     bool disableHands {false}; // should go away with rig animation (and Rig::inverseKinematics)
 
+    glm::vec3 getModelOffset() const;
+
  protected:
 
     void updateLeanJoint(int index, float leanSideways, float leanForward, float torsoTwist);