diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 7e5a777484..de9b33d9c7 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -499,13 +499,19 @@ bool Avatar::findSphereCollisions(const glm::vec3& penetratorCenter, float penet
     //return getHead()->getFaceModel().findSphereCollisions(penetratorCenter, penetratorRadius, collisions);
 }
 
-bool Avatar::findCollisions(const QVector<const Shape*>& shapes, CollisionList& collisions) {
+void Avatar::updateShapePositions() {
     _skeletonModel.updateShapePositions();
-    bool collided = _skeletonModel.findCollisions(shapes, collisions);
-
     Model& headModel = getHead()->getFaceModel();
     headModel.updateShapePositions();
-    collided = headModel.findCollisions(shapes, collisions);
+}
+
+bool Avatar::findCollisions(const QVector<const Shape*>& shapes, CollisionList& collisions) {
+    // TODO: Andrew to fix: also collide against _skeleton
+    //bool collided = _skeletonModel.findCollisions(shapes, collisions);
+
+    Model& headModel = getHead()->getFaceModel();
+    //collided = headModel.findCollisions(shapes, collisions) || collided;
+    bool collided = headModel.findCollisions(shapes, collisions);
     return collided;
 }
 
@@ -752,17 +758,30 @@ bool Avatar::collisionWouldMoveAvatar(CollisionInfo& collision) const {
     return false;
 }
 
-void Avatar::applyCollision(CollisionInfo& collision) {
-    if (!collision._data || collision._type != MODEL_COLLISION) {
-        return;
-    }
-    // TODO: make skeleton also respond to collisions
-    Model* model = static_cast<Model*>(collision._data);
-    if (model == &(getHead()->getFaceModel())) {
-        getHead()->applyCollision(collision);
+void Avatar::applyCollision(const glm::vec3& contactPoint, const glm::vec3& penetration) {
+    // compute lean angles
+    glm::vec3 leverAxis = contactPoint - getPosition();
+    float leverLength = glm::length(leverAxis);
+    if (leverLength > EPSILON) {
+        glm::quat bodyRotation = getOrientation();
+        glm::vec3 xAxis = bodyRotation * glm::vec3(1.f, 0.f, 0.f);
+        glm::vec3 zAxis = bodyRotation * glm::vec3(0.f, 0.f, 1.f);
+
+        leverAxis = leverAxis / leverLength;
+        glm::vec3 effectivePenetration = penetration - glm::dot(penetration, leverAxis) * leverAxis;
+        // we use the small-angle approximation for sine below to compute the length of 
+        // the opposite side of a narrow right triangle
+        float sideways = - glm::dot(effectivePenetration, xAxis) / leverLength;
+        float forward = glm::dot(effectivePenetration, zAxis) / leverLength;
+        getHead()->addLean(sideways, forward);
     }
 }
 
+float Avatar::getBoundingRadius() const {
+    // TODO: also use head model when computing the avatar's bounding radius
+    return _skeletonModel.getBoundingRadius();
+}
+
 float Avatar::getPelvisFloatingHeight() const {
     return -_skeletonModel.getBindExtents().minimum.y;
 }
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index 25600e0943..685705bfc4 100755
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -145,10 +145,11 @@ public:
     /// \return true if we expect the avatar would move as a result of the collision
     bool collisionWouldMoveAvatar(CollisionInfo& collision) const;
 
-    /// \param collision a data structure for storing info about collisions against Models
-    void applyCollision(CollisionInfo& collision);
+    void applyCollision(const glm::vec3& contactPoint, const glm::vec3& penetration);
 
-    float getBoundingRadius() const { return 0.5f * getSkeletonHeight(); }
+    /// \return bounding radius of avatar
+    virtual float getBoundingRadius() const;
+    void updateShapePositions();
 
 public slots:
     void updateCollisionFlags();
diff --git a/interface/src/avatar/Hand.cpp b/interface/src/avatar/Hand.cpp
index 77586dd7ae..750fae7b2a 100644
--- a/interface/src/avatar/Hand.cpp
+++ b/interface/src/avatar/Hand.cpp
@@ -9,6 +9,7 @@
 #include <NodeList.h>
 
 #include <GeometryUtil.h>
+#include <StreamUtils.h>
 
 #include "Application.h"
 #include "Avatar.h"
@@ -109,8 +110,6 @@ void Hand::collideAgainstAvatarOld(Avatar* avatar, bool isMyHand) {
             for (int j = 0; j < handCollisions.size(); ++j) {
                 CollisionInfo* collision = handCollisions.getCollision(j);
                 if (isMyHand) {
-                    // we resolve the hand from collision when it belongs to MyAvatar AND the other Avatar is 
-                    // not expected to respond to the collision (hand hit unmovable part of their Avatar)
                     totalPenetration = addPenetrations(totalPenetration, collision->_penetration);
                 }
             }
@@ -128,55 +127,37 @@ void Hand::collideAgainstAvatar(Avatar* avatar, bool isMyHand) {
         return;
     }
 
-    // 2 = NUM_HANDS
-    int palmIndices[2];
-    getLeftRightPalmIndices(*palmIndices, *(palmIndices + 1));
-
     const SkeletonModel& skeletonModel = _owningAvatar->getSkeletonModel();
     int jointIndices[2];
     jointIndices[0] = skeletonModel.getLeftHandJointIndex();
     jointIndices[1] = skeletonModel.getRightHandJointIndex();
 
-    palmIndices[1] = -1;    // adebug temporarily disable right hand
-    jointIndices[1] = -1;   // adebug temporarily disable right hand
-
-    for (size_t i = 0; i < 1; i++) {
-        int palmIndex = palmIndices[i];
+    for (size_t i = 0; i < 2; i++) {
         int jointIndex = jointIndices[i];
-        if (palmIndex == -1 || jointIndex == -1) {
+        if (jointIndex < 0) {
             continue;
         }
-        PalmData& palm = _palms[palmIndex];
-        if (!palm.isActive()) {
-            continue;
-        }
-        if (isMyHand && Menu::getInstance()->isOptionChecked(MenuOption::PlaySlaps)) {
-            playSlaps(palm, avatar);
-        }
 
         handCollisions.clear();
         QVector<const Shape*> shapes;
         skeletonModel.getHandShapes(jointIndex, shapes);
-        bool collided = isMyHand ? avatar->findCollisions(shapes, handCollisions) : avatar->findCollisions(shapes, handCollisions);
-        if (collided) {
-        //if (avatar->findCollisions(shapes, handCollisions)) {
-            glm::vec3 averagePenetration;
+
+        if (avatar->findCollisions(shapes, handCollisions)) {
+            glm::vec3 totalPenetration(0.f);
             glm::vec3 averageContactPoint;
             for (int j = 0; j < handCollisions.size(); ++j) {
                 CollisionInfo* collision = handCollisions.getCollision(j);
-                averagePenetration += collision->_penetration;
+                totalPenetration += collision->_penetration;
                 averageContactPoint += collision->_contactPoint;
             }
-            averagePenetration /= float(handCollisions.size());
             if (isMyHand) {
                 // our hand against other avatar 
-                // for now we resolve it to test shapes/collisions
-                // TODO: only partially resolve this penetration
-                palm.addToPosition(-averagePenetration);
+                // TODO: resolve this penetration when we don't think the other avatar will yield
+                //palm.addToPenetration(averagePenetration);
             } else {
                 // someone else's hand against MyAvatar
-                // TODO: submit collision info to MyAvatar which should lean accordingly
                 averageContactPoint /= float(handCollisions.size());
+                avatar->applyCollision(averageContactPoint, totalPenetration);
             }
         }
     }
@@ -192,7 +173,7 @@ void Hand::collideAgainstOurself() {
     float scaledPalmRadius = PALM_COLLISION_RADIUS * _owningAvatar->getScale();
     
     const Model& skeletonModel = _owningAvatar->getSkeletonModel();
-    for (size_t i = 0; i < getNumPalms(); i++) {
+    for (int i = 0; i < int(getNumPalms()); i++) {
         PalmData& palm = getPalms()[i];
         if (!palm.isActive()) {
             continue;
@@ -210,11 +191,18 @@ void Hand::collideAgainstOurself() {
                 totalPenetration = addPenetrations(totalPenetration, collision->_penetration);
             }
             // resolve penetration
-            palm.addToPosition(-totalPenetration);
+            palm.addToPenetration(totalPenetration);
         }
     }
 }
 
+void Hand::resolvePenetrations() {
+    for (size_t i = 0; i < getNumPalms(); ++i) {
+        PalmData& palm = getPalms()[i];
+        palm.resolvePenetrations();
+    }
+}
+
 void Hand::calculateGeometry() {
     // generate finger tip balls....
     _leapFingerTipBalls.clear();
@@ -385,19 +373,3 @@ void Hand::renderLeapHands(bool isMine) {
     glPopMatrix();
 }
 
-
-void Hand::setLeapHands(const std::vector<glm::vec3>& handPositions,
-                          const std::vector<glm::vec3>& handNormals) {
-    for (size_t i = 0; i < getNumPalms(); ++i) {
-        PalmData& palm = getPalms()[i];
-        if (i < handPositions.size()) {
-            palm.setActive(true);
-            palm.setRawPosition(handPositions[i]);
-            palm.setRawNormal(handNormals[i]);
-        }
-        else {
-            palm.setActive(false);
-        }
-    }
-}
-
diff --git a/interface/src/avatar/Hand.h b/interface/src/avatar/Hand.h
index f6ee5b281f..3be3bc0f77 100755
--- a/interface/src/avatar/Hand.h
+++ b/interface/src/avatar/Hand.h
@@ -59,6 +59,8 @@ public:
     void collideAgainstAvatar(Avatar* avatar, bool isMyHand);
     void collideAgainstOurself();
 
+    void resolvePenetrations();
+
 private:
     // disallow copies of the Hand, copy of owning Avatar is disallowed too
     Hand(const Hand&);
@@ -71,10 +73,6 @@ private:
     std::vector<HandBall> _leapFingerTipBalls;
     std::vector<HandBall> _leapFingerRootBalls;
     
-    // private methods
-    void setLeapHands(const std::vector<glm::vec3>& handPositions,
-                      const std::vector<glm::vec3>& handNormals);
-
     void renderLeapHands(bool isMine);
     void renderLeapFingerTrails();
     
@@ -84,3 +82,4 @@ private:
 };
 
 #endif
+
diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index 4a81df8b74..b1265a1e51 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -212,34 +212,6 @@ float Head::getTweakedRoll() const {
     return glm::clamp(_roll + _rollTweak, MIN_HEAD_ROLL, MAX_HEAD_ROLL);
 }
 
-void Head::applyCollision(CollisionInfo& collision) {
-    // HACK: the collision proxies for the FaceModel are bad.  As a temporary workaround
-    // we collide against a hard coded collision proxy.
-    // TODO: get a better collision proxy here.
-    const float HEAD_RADIUS = 0.15f;
-    const glm::vec3 HEAD_CENTER = _position;
-
-    // collide the contactPoint against the collision proxy to obtain a new penetration
-    // NOTE: that penetration is in opposite direction (points the way out for the point, not the sphere)
-    glm::vec3 penetration;
-    if (findPointSpherePenetration(collision._contactPoint, HEAD_CENTER, HEAD_RADIUS, penetration)) {
-        // compute lean angles
-        Avatar* owningAvatar = static_cast<Avatar*>(_owningAvatar);
-        glm::quat bodyRotation = owningAvatar->getOrientation();
-        glm::vec3 neckPosition;
-        if (owningAvatar->getSkeletonModel().getNeckPosition(neckPosition)) {
-            glm::vec3 xAxis = bodyRotation * glm::vec3(1.f, 0.f, 0.f);
-            glm::vec3 zAxis = bodyRotation * glm::vec3(0.f, 0.f, 1.f);
-            float neckLength = glm::length(_position - neckPosition);
-            if (neckLength > 0.f) {
-                float forward = glm::dot(collision._penetration, zAxis) / neckLength;
-                float sideways = - glm::dot(collision._penetration, xAxis) / neckLength;
-                addLean(sideways, forward);
-            }
-        }
-    } 
-}
-
 void Head::renderLookatVectors(glm::vec3 leftEyePosition, glm::vec3 rightEyePosition, glm::vec3 lookatPosition) {
 
     Application::getInstance()->getGlowEffect()->begin();
diff --git a/interface/src/avatar/Head.h b/interface/src/avatar/Head.h
index 60730c8724..733323abc5 100644
--- a/interface/src/avatar/Head.h
+++ b/interface/src/avatar/Head.h
@@ -82,8 +82,6 @@ public:
     virtual float getTweakedPitch() const;
     virtual float getTweakedYaw() const;
     virtual float getTweakedRoll() const;
-
-    void  applyCollision(CollisionInfo& collisionInfo);
     
 private:
     // disallow copies of the Head, copy of owning Avatar is disallowed too
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 19d15fb803..618cda1199 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -177,26 +177,6 @@ void MyAvatar::simulate(float deltaTime) {
         _velocity += _scale * _gravity * (GRAVITY_EARTH * deltaTime);
     }
 
-    if (_collisionFlags != 0) {
-        Camera* myCamera = Application::getInstance()->getCamera();
-
-        float radius = getSkeletonHeight() * COLLISION_RADIUS_SCALE;
-        if (myCamera->getMode() == CAMERA_MODE_FIRST_PERSON && !OculusManager::isConnected()) {
-            radius = myCamera->getAspectRatio() * (myCamera->getNearClip() / cosf(0.5f * RADIANS_PER_DEGREE * myCamera->getFieldOfView()));
-            radius *= COLLISION_RADIUS_SCALAR;
-        }
-
-        if (_collisionFlags & COLLISION_GROUP_ENVIRONMENT) {
-            updateCollisionWithEnvironment(deltaTime, radius);
-        }
-        if (_collisionFlags & COLLISION_GROUP_VOXELS) {
-            updateCollisionWithVoxels(deltaTime, radius);
-        }
-        if (_collisionFlags & COLLISION_GROUP_AVATARS) {
-            updateCollisionWithAvatars(deltaTime);
-        }
-    }
-
     // add thrust to velocity
     _velocity += _thrust * deltaTime;
 
@@ -320,7 +300,28 @@ void MyAvatar::simulate(float deltaTime) {
 
     // Zero thrust out now that we've added it to velocity in this frame
     _thrust = glm::vec3(0, 0, 0);
-    
+
+    // now that we're done stepping the avatar forward in time, compute new collisions
+    if (_collisionFlags != 0) {
+        Camera* myCamera = Application::getInstance()->getCamera();
+
+        float radius = getSkeletonHeight() * COLLISION_RADIUS_SCALE;
+        if (myCamera->getMode() == CAMERA_MODE_FIRST_PERSON && !OculusManager::isConnected()) {
+            radius = myCamera->getAspectRatio() * (myCamera->getNearClip() / cos(myCamera->getFieldOfView() / 2.f));
+            radius *= COLLISION_RADIUS_SCALAR;
+        }
+
+        if (_collisionFlags & COLLISION_GROUP_ENVIRONMENT) {
+            updateCollisionWithEnvironment(deltaTime, radius);
+        }
+        if (_collisionFlags & COLLISION_GROUP_VOXELS) {
+            updateCollisionWithVoxels(deltaTime, radius);
+        }
+        if (_collisionFlags & COLLISION_GROUP_AVATARS) {
+            updateCollisionWithAvatars(deltaTime);
+        }
+    }
+
     // consider updating our billboard
     maybeUpdateBillboard();
 }
@@ -361,7 +362,7 @@ void MyAvatar::updateFromGyros(float deltaTime) {
         }
     } else {
         // restore rotation, lean to neutral positions
-        const float RESTORE_PERIOD = 1.f;   // seconds
+        const float RESTORE_PERIOD = 0.25f;   // seconds
         float restorePercentage = glm::clamp(deltaTime/RESTORE_PERIOD, 0.f, 1.f);
         head->setPitchTweak(glm::mix(head->getPitchTweak(), 0.0f, restorePercentage));
         head->setYawTweak(glm::mix(head->getYawTweak(), 0.0f, restorePercentage));
@@ -881,35 +882,31 @@ void MyAvatar::updateCollisionWithAvatars(float deltaTime) {
         // no need to compute a bunch of stuff if we have one or fewer avatars
         return;
     }
+    updateShapePositions();
     float myBoundingRadius = getBoundingRadius();
 
+    /* TODO: Andrew to fix Avatar-Avatar body collisions
     // HACK: body-body collision uses two coaxial capsules with axes parallel to y-axis
     // TODO: make the collision work without assuming avatar orientation
+    Extents myStaticExtents = _skeletonModel.getStaticExtents();
+    glm::vec3 staticScale = myStaticExtents.maximum - myStaticExtents.minimum;
+    float myCapsuleRadius = 0.25f * (staticScale.x + staticScale.z);
+    float myCapsuleHeight = staticScale.y;
+    */
 
-    // TODO: these local variables are not used in the live code, only in the
-    // commented-outTODO code below.
-    //Extents myStaticExtents = _skeletonModel.getStaticExtents();
-    //glm::vec3 staticScale = myStaticExtents.maximum - myStaticExtents.minimum;
-    //float myCapsuleRadius = 0.25f * (staticScale.x + staticScale.z);
-    //float myCapsuleHeight = staticScale.y;
-
-    CollisionInfo collisionInfo;
     foreach (const AvatarSharedPointer& avatarPointer, avatars) {
         Avatar* avatar = static_cast<Avatar*>(avatarPointer.data());
         if (static_cast<Avatar*>(this) == avatar) {
             // don't collide with ourselves
             continue;
         }
+        avatar->updateShapePositions();
         float distance = glm::length(_position - avatar->getPosition());        
         if (_distanceToNearestAvatar > distance) {
             _distanceToNearestAvatar = distance;
         }
         float theirBoundingRadius = avatar->getBoundingRadius();
         if (distance < myBoundingRadius + theirBoundingRadius) {
-            _skeletonModel.updateShapePositions();
-            Model& headModel = getHead()->getFaceModel();
-            headModel.updateShapePositions();
-
             /* TODO: Andrew to fix Avatar-Avatar body collisions
             Extents theirStaticExtents = _skeletonModel.getStaticExtents();
             glm::vec3 staticScale = theirStaticExtents.maximum - theirStaticExtents.minimum;
@@ -925,12 +922,16 @@ void MyAvatar::updateCollisionWithAvatars(float deltaTime) {
             */
 
             // collide our hands against them
-            getHand()->collideAgainstAvatar(avatar, true);
+            // TODO: make this work when we can figure out when the other avatar won't yeild
+            // (for example, we're colling against their chest or leg)
+            //getHand()->collideAgainstAvatar(avatar, true);
 
             // collide their hands against us
             avatar->getHand()->collideAgainstAvatar(this, false);
         }
     }
+    // TODO: uncomment this when we handle collisions that won't affect other avatar
+    //getHand()->resolvePenetrations();
 }
 
 class SortedAvatar {
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index 9e4740df15..b4746a39d2 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -63,13 +63,30 @@ void SkeletonModel::simulate(float deltaTime, bool fullUpdate) {
 }
 
 void SkeletonModel::getHandShapes(int jointIndex, QVector<const Shape*>& shapes) const {
-    if (jointIndex == -1) {
+    if (jointIndex < 0 || jointIndex >= int(_shapes.size())) {
         return;
     }
     if (jointIndex == getLeftHandJointIndex()
         || jointIndex == getRightHandJointIndex()) {
-        // TODO: also add fingers and other hand-parts
-        shapes.push_back(_shapes[jointIndex]);
+        // get all shapes that have this hand as an ancestor in the skeleton heirarchy
+        const FBXGeometry& geometry = _geometry->getFBXGeometry();
+        for (int i = 0; i < _jointStates.size(); i++) {
+            const FBXJoint& joint = geometry.joints[i];
+            if (i == jointIndex) {
+                // this shape is the hand
+                shapes.push_back(_shapes[i]);
+            } else {
+                int parentIndex = joint.parentIndex;
+                while (parentIndex != -1) {
+                    if (parentIndex == jointIndex) {
+                        // this shape is a child of the hand
+                        shapes.push_back(_shapes[i]);
+                        break;
+                    }
+                    parentIndex = geometry.joints[parentIndex].parentIndex;
+                }
+            }
+        }
     }
 }
 
diff --git a/interface/src/avatar/SkeletonModel.h b/interface/src/avatar/SkeletonModel.h
index 514b5daf1c..213a53d9ed 100644
--- a/interface/src/avatar/SkeletonModel.h
+++ b/interface/src/avatar/SkeletonModel.h
@@ -27,7 +27,7 @@ public:
     /// \param jointIndex index of hand joint
     /// \param shapes[out] list in which is stored pointers to hand shapes
     void getHandShapes(int jointIndex, QVector<const Shape*>& shapes) const;
-    
+
 protected:
     
     void applyHandPosition(int jointIndex, const glm::vec3& position);
diff --git a/interface/src/renderer/Model.cpp b/interface/src/renderer/Model.cpp
index 690b19ee5e..df5560a4b1 100644
--- a/interface/src/renderer/Model.cpp
+++ b/interface/src/renderer/Model.cpp
@@ -11,6 +11,7 @@
 #include <QThreadPool>
 
 #include <glm/gtx/transform.hpp>
+#include <glm/gtx/norm.hpp>
 
 #include <GeometryUtil.h>
 
@@ -32,7 +33,8 @@ Model::Model(QObject* parent) :
     _scale(1.0f, 1.0f, 1.0f),
     _shapesAreDirty(true),
     _lodDistance(0.0f),
-    _pupilDilation(0.0f) {
+    _pupilDilation(0.0f),
+    _boundingRadius(0.f) {
     // we may have been created in the network thread, but we live in the main thread
     moveToThread(Application::getInstance()->thread());
 }
@@ -164,6 +166,7 @@ void Model::createCollisionShapes() {
 
 void Model::updateShapePositions() {
     if (_shapesAreDirty && _shapes.size() == _jointStates.size()) {
+        _boundingRadius = 0.f;
         float uniformScale = extractUniformScale(_scale);
         const FBXGeometry& geometry = _geometry->getFBXGeometry();
         for (int i = 0; i < _jointStates.size(); i++) {
@@ -173,7 +176,12 @@ void Model::updateShapePositions() {
             glm::vec3 worldPosition = extractTranslation(_jointStates[i].transform) + jointToShapeOffset + _translation;
             _shapes[i]->setPosition(worldPosition);
             _shapes[i]->setRotation(_jointStates[i].combinedRotation * joint.shapeRotation);
+            float distance2 = glm::distance2(worldPosition, _translation);
+            if (distance2 > _boundingRadius) {
+                _boundingRadius = distance2;
+            }
         }
+        _boundingRadius = sqrtf(_boundingRadius);
         _shapesAreDirty = false;
     }
 }
@@ -321,18 +329,10 @@ bool Model::getRightHandRotation(glm::quat& rotation) const {
     return getJointRotation(getRightHandJointIndex(), rotation);
 }
 
-bool Model::setLeftHandPosition(const glm::vec3& position) {
-    return setJointPosition(getLeftHandJointIndex(), position);
-}
-
 bool Model::restoreLeftHandPosition(float percent) {
     return restoreJointPosition(getLeftHandJointIndex(), percent);
 }
 
-bool Model::setLeftHandRotation(const glm::quat& rotation) {
-    return setJointRotation(getLeftHandJointIndex(), rotation);
-}
-
 bool Model::getLeftShoulderPosition(glm::vec3& position) const {
     return getJointPosition(getLastFreeJointIndex(getLeftHandJointIndex()), position);
 }
@@ -341,18 +341,10 @@ float Model::getLeftArmLength() const {
     return getLimbLength(getLeftHandJointIndex());
 }
 
-bool Model::setRightHandPosition(const glm::vec3& position) {
-    return setJointPosition(getRightHandJointIndex(), position);
-}
-
 bool Model::restoreRightHandPosition(float percent) {
     return restoreJointPosition(getRightHandJointIndex(), percent);
 }
 
-bool Model::setRightHandRotation(const glm::quat& rotation) {
-    return setJointRotation(getRightHandJointIndex(), rotation);
-}
-
 bool Model::getRightShoulderPosition(glm::vec3& position) const {
     return getJointPosition(getLastFreeJointIndex(getRightHandJointIndex()), position);
 }
diff --git a/interface/src/renderer/Model.h b/interface/src/renderer/Model.h
index b4f71f14d3..3fdf1cd291 100644
--- a/interface/src/renderer/Model.h
+++ b/interface/src/renderer/Model.h
@@ -135,19 +135,11 @@ public:
     /// \return true whether or not the rotation was found
     bool getRightHandRotation(glm::quat& rotation) const;
     
-    /// Sets the position of the left hand using inverse kinematics.
-    /// \return whether or not the left hand joint was found
-    bool setLeftHandPosition(const glm::vec3& position);
-    
     /// Restores some percentage of the default position of the left hand.
     /// \param percent the percentage of the default position to restore
     /// \return whether or not the left hand joint was found
     bool restoreLeftHandPosition(float percent = 1.0f);
     
-    /// Sets the rotation of the left hand.
-    /// \return whether or not the left hand joint was found
-    bool setLeftHandRotation(const glm::quat& rotation);
-    
     /// Gets the position of the left shoulder.
     /// \return whether or not the left shoulder joint was found
     bool getLeftShoulderPosition(glm::vec3& position) const;
@@ -155,19 +147,11 @@ public:
     /// Returns the extended length from the left hand to its last free ancestor.
     float getLeftArmLength() const;
     
-    /// Sets the position of the right hand using inverse kinematics.
-    /// \return whether or not the right hand joint was found
-    bool setRightHandPosition(const glm::vec3& position);
-    
     /// Restores some percentage of the default position of the right hand.
     /// \param percent the percentage of the default position to restore
     /// \return whether or not the right hand joint was found
     bool restoreRightHandPosition(float percent = 1.0f);
     
-    /// Sets the rotation of the right hand.
-    /// \return whether or not the right hand joint was found
-    bool setRightHandRotation(const glm::quat& rotation);
-    
     /// Gets the position of the right shoulder.
     /// \return whether or not the right shoulder joint was found
     bool getRightShoulderPosition(glm::vec3& position) const;
@@ -195,6 +179,8 @@ public:
     /// Use the collision to affect the model
     void applyCollision(CollisionInfo& collision);
 
+    float getBoundingRadius() const { return _boundingRadius; }
+
     /// Sets blended vertices computed in a separate thread.
     void setBlendedVertices(const QVector<glm::vec3>& vertices, const QVector<glm::vec3>& normals);
 
@@ -254,7 +240,7 @@ protected:
     /// Computes and returns the extended length of the limb terminating at the specified joint and starting at the joint's
     /// first free ancestor.
     float getLimbLength(int jointIndex) const;
-    
+
     void applyRotationDelta(int jointIndex, const glm::quat& delta, bool constrain = true);
     
 private:
@@ -280,6 +266,8 @@ private:
     QVector<QVector<QSharedPointer<Texture> > > _dilatedTextures;
     
     QVector<Model*> _attachments;
+
+    float _boundingRadius;
     
     static ProgramObject _program;
     static ProgramObject _normalMapProgram;
diff --git a/libraries/avatars/src/HandData.cpp b/libraries/avatars/src/HandData.cpp
index 78ebf4b921..201d17d3f5 100644
--- a/libraries/avatars/src/HandData.cpp
+++ b/libraries/avatars/src/HandData.cpp
@@ -61,11 +61,12 @@ void HandData::getLeftRightPalmIndices(int& leftPalmIndex, int& rightPalmIndex)
 }
 
 PalmData::PalmData(HandData* owningHandData) :
-_rawRotation(0, 0, 0, 1),
-_rawPosition(0, 0, 0),
-_rawNormal(0, 1, 0),
-_rawVelocity(0, 0, 0),
-_rotationalVelocity(0, 0, 0),
+_rawRotation(0.f, 0.f, 0.f, 1.f),
+_rawPosition(0.f),
+_rawNormal(0.f, 1.f, 0.f),
+_rawVelocity(0.f),
+_rotationalVelocity(0.f),
+_totalPenetration(0.f),
 _controllerButtons(0),
 _isActive(false),
 _leapID(LEAPID_INVALID),
diff --git a/libraries/avatars/src/HandData.h b/libraries/avatars/src/HandData.h
index fffc596247..9ebdc8dcf6 100755
--- a/libraries/avatars/src/HandData.h
+++ b/libraries/avatars/src/HandData.h
@@ -154,6 +154,9 @@ public:
     void setRawVelocity(const glm::vec3& velocity) { _rawVelocity = velocity; }
     const glm::vec3& getRawVelocity()  const { return _rawVelocity; }
     void addToPosition(const glm::vec3& delta);
+
+    void addToPenetration(const glm::vec3& penetration) { _totalPenetration += penetration; }
+    void resolvePenetrations() { addToPosition(-_totalPenetration); _totalPenetration = glm::vec3(0.f); }
     
     void setTipPosition(const glm::vec3& position) { _tipPosition = position; }
     const glm::vec3 getTipPosition() const { return _owningHandData->leapPositionToWorldPosition(_tipPosition); }
@@ -203,6 +206,7 @@ private:
     
     glm::vec3 _tipPosition;
     glm::vec3 _tipVelocity;
+    glm::vec3 _totalPenetration;    // accumulator for per-frame penetrations
     unsigned int _controllerButtons;
     unsigned int _lastControllerButtons;
     float _trigger;
diff --git a/libraries/shared/src/ShapeCollider.cpp b/libraries/shared/src/ShapeCollider.cpp
index e83e6842a9..70f9b9c4bf 100644
--- a/libraries/shared/src/ShapeCollider.cpp
+++ b/libraries/shared/src/ShapeCollider.cpp
@@ -86,7 +86,8 @@ bool sphereCapsule(const SphereShape* sphereA, const CapsuleShape* capsuleB, Col
     if (absAxialDistance < totalRadius + capsuleB->getHalfHeight()) {
         glm::vec3 radialAxis = BA + axialDistance * capsuleAxis; // points from A to axis of B
         float radialDistance2 = glm::length2(radialAxis);
-        if (radialDistance2 > totalRadius * totalRadius) {
+        float totalRadius2 = totalRadius * totalRadius;
+        if (radialDistance2 > totalRadius2) {
             // sphere is too far from capsule axis
             return false;
         }
@@ -95,6 +96,9 @@ bool sphereCapsule(const SphereShape* sphereA, const CapsuleShape* capsuleB, Col
             float sign = (axialDistance > 0.f) ? 1.f : -1.f;
             radialAxis = BA + (sign * capsuleB->getHalfHeight()) * capsuleAxis;
             radialDistance2 = glm::length2(radialAxis);
+            if (radialDistance2 > totalRadius2) {
+                return false;
+            }
         }
         if (radialDistance2 > EPSILON * EPSILON) {
             CollisionInfo* collision = collisions.getNewCollision();
@@ -147,7 +151,8 @@ bool capsuleSphere(const CapsuleShape* capsuleA, const SphereShape* sphereB, Col
     if (absAxialDistance < totalRadius + capsuleA->getHalfHeight()) {
         glm::vec3 radialAxis = AB + axialDistance * capsuleAxis; // from sphereB to axis of capsuleA
         float radialDistance2 = glm::length2(radialAxis);
-        if (radialDistance2 > totalRadius * totalRadius) {
+        float totalRadius2 = totalRadius * totalRadius;
+        if (radialDistance2 > totalRadius2) {
             // sphere is too far from capsule axis
             return false;
         }
@@ -162,6 +167,9 @@ bool capsuleSphere(const CapsuleShape* capsuleA, const SphereShape* sphereB, Col
             closestApproach = capsuleA->getPosition() + (sign * capsuleA->getHalfHeight()) * capsuleAxis;
             radialAxis = closestApproach - sphereB->getPosition();
             radialDistance2 = glm::length2(radialAxis);
+            if (radialDistance2 > totalRadius2) {
+                return false;
+            }
         }
         if (radialDistance2 > EPSILON * EPSILON) {
             CollisionInfo* collision = collisions.getNewCollision();
diff --git a/libraries/shared/src/StreamUtils.cpp b/libraries/shared/src/StreamUtils.cpp
new file mode 100644
index 0000000000..44c81f9464
--- /dev/null
+++ b/libraries/shared/src/StreamUtils.cpp
@@ -0,0 +1,75 @@
+//
+//  StreamUtils.cpp
+//
+//  Created by Andrew Meadows on 2014.02.21
+//  Copyright (c) 2014 High Fidelity, Inc. All rights reserved.
+//
+
+#include <glm/gtc/type_ptr.hpp>
+
+#include "StreamUtils.h"
+
+const char* hex_digits = "0123456789abcdef";
+
+void StreamUtil::dump(std::ostream& s, const QByteArray& buffer) {
+    int row_size = 32;
+    int i = 0;
+    while (i < buffer.size()) {
+        for(int j = 0; i < buffer.size() && j < row_size; ++j) {
+            char byte = buffer[i];
+            s << hex_digits[(byte >> 4) & 0x0f] << hex_digits[byte & 0x0f] << " ";
+            ++i;
+        }
+        s << "\n";
+    }
+}
+
+std::ostream& operator<<(std::ostream& s, const glm::vec3& v) {
+    s << "<" << v.x << " " << v.y << " " << v.z << ">";
+    return s;
+}
+
+std::ostream& operator<<(std::ostream& s, const glm::quat& q) {
+    s << "<" << q.x << " " << q.y << " " << q.z << " " << q.w << ">";
+    return s;
+}
+
+std::ostream& operator<<(std::ostream& s, const glm::mat4& m) {
+    s << "[";
+    for (int j = 0; j < 4; ++j) {
+        s << " " << m[0][j] << " " << m[1][j] << " " << m[2][j] << " " << m[3][j] << ";";
+    }
+    s << "  ]";
+    return s;
+}
+
+// less common utils can be enabled with DEBUG
+#ifdef DEBUG
+
+std::ostream& operator<<(std::ostream& s, const CollisionInfo& c) {
+    s << "{penetration=" << c._penetration 
+        << ", contactPoint=" << c._contactPoint
+        << ", addedVelocity=" << c._addedVelocity
+        << "}";
+    return s;
+}
+
+std::ostream& operator<<(std::ostream& s, const SphereShape& sphere) {
+    s << "{type='sphere', center=" << sphere.getPosition()
+        << ", radius=" << sphere.getRadius()
+        << "}";
+    return s;
+}
+
+std::ostream& operator<<(std::ostream& s, const CapsuleShape& capsule) {
+    s << "{type='capsule', center=" << capsule.getPosition()
+        << ", radius=" << capsule.getRadius()
+        << ", length=" << (2.f * capsule.getHalfHeight())
+        << ", begin=" << capsule.getStartPoint()
+        << ", end=" << capsule.getEndPoint()
+        << "}";
+    return s;
+}
+
+#endif // DEBUG
+
diff --git a/libraries/shared/src/StreamUtils.h b/libraries/shared/src/StreamUtils.h
new file mode 100644
index 0000000000..1a17a94658
--- /dev/null
+++ b/libraries/shared/src/StreamUtils.h
@@ -0,0 +1,39 @@
+//
+//  StreamUtils.h
+//
+//  Created by Andrew Meadows on 2014.02.21
+//  Copyright (c) 2014 High Fidelity, Inc. All rights reserved.
+//
+
+#ifndef __tests__StreamUtils__
+#define __tests__StreamUtils__
+
+#include <iostream>
+
+#include <QByteArray>
+
+#include <glm/glm.hpp>
+#include <glm/gtx/quaternion.hpp>
+
+
+namespace StreamUtil {
+    // dump the buffer, 32 bytes per row, each byte in hex, separated by whitespace
+    void dump(std::ostream& s, const QByteArray& buffer);
+}
+
+std::ostream& operator<<(std::ostream& s, const glm::vec3& v);
+std::ostream& operator<<(std::ostream& s, const glm::quat& q);
+std::ostream& operator<<(std::ostream& s, const glm::mat4& m);
+
+// less common utils can be enabled with DEBUG
+#ifdef DEBUG
+#include "CollisionInfo.h"
+#include "SphereShape.h"
+#include "CapsuleShape.h"
+std::ostream& operator<<(std::ostream& s, const CollisionInfo& c);
+std::ostream& operator<<(std::ostream& s, const SphereShape& shape);
+std::ostream& operator<<(std::ostream& s, const CapsuleShape& capsule);
+#endif // DEBUG
+
+
+#endif // __tests__StreamUtils__
diff --git a/tests/physics/src/CollisionInfoTests.cpp b/tests/physics/src/CollisionInfoTests.cpp
index 43601978ae..241204d036 100644
--- a/tests/physics/src/CollisionInfoTests.cpp
+++ b/tests/physics/src/CollisionInfoTests.cpp
@@ -13,12 +13,17 @@
 
 #include <CollisionInfo.h>
 #include <SharedUtil.h>
+#include <StreamUtils.h>
 
 #include "CollisionInfoTests.h"
-#include "PhysicsTestUtil.h"
 
 
 /*
+
+static glm::vec3 xAxis(1.f, 0.f, 0.f);
+static glm::vec3 xZxis(0.f, 1.f, 0.f);
+static glm::vec3 xYxis(0.f, 0.f, 1.f);
+
 void CollisionInfoTests::rotateThenTranslate() {
     CollisionInfo collision;
     collision._penetration = xAxis;
diff --git a/tests/physics/src/ShapeColliderTests.cpp b/tests/physics/src/ShapeColliderTests.cpp
index 6d7e9a6db1..4a2e648323 100644
--- a/tests/physics/src/ShapeColliderTests.cpp
+++ b/tests/physics/src/ShapeColliderTests.cpp
@@ -16,11 +16,14 @@
 #include <ShapeCollider.h>
 #include <SharedUtil.h>
 #include <SphereShape.h>
+#include <StreamUtils.h>
 
-#include "PhysicsTestUtil.h"
 #include "ShapeColliderTests.h"
 
 const glm::vec3 origin(0.f);
+static const glm::vec3 xAxis(1.f, 0.f, 0.f);
+static const glm::vec3 yAxis(0.f, 1.f, 0.f);
+static const glm::vec3 zAxis(0.f, 0.f, 1.f);
 
 void ShapeColliderTests::sphereMissesSphere() {
     // non-overlapping spheres of unequal size