diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 9463c19dc6..00b40bc46b 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -57,6 +57,7 @@
 #include "Util.h"
 #include "devices/LeapManager.h"
 #include "devices/OculusManager.h"
+#include "devices/TV3DManager.h"
 #include "renderer/ProgramObject.h"
 #include "ui/TextRenderer.h"
 #include "InfoView.h"
@@ -439,7 +440,10 @@ void Application::paintGL() {
 
     if (OculusManager::isConnected()) {
         OculusManager::display(whichCamera);
-        
+    } else if (TV3DManager::isConnected()) {
+        _glowEffect.prepare(); 
+        TV3DManager::display(whichCamera);
+        _glowEffect.render();
     } else {
         _glowEffect.prepare(); 
         
@@ -474,8 +478,10 @@ void Application::paintGL() {
             _mirrorCamera.update(1.0f/_fps);
             
             // set the bounds of rear mirror view
-            glViewport(_mirrorViewRect.x(), _glWidget->height() - _mirrorViewRect.y() - _mirrorViewRect.height(), _mirrorViewRect.width(), _mirrorViewRect.height());
-            glScissor(_mirrorViewRect.x(), _glWidget->height() - _mirrorViewRect.y() - _mirrorViewRect.height(), _mirrorViewRect.width(), _mirrorViewRect.height());
+            glViewport(_mirrorViewRect.x(), _glWidget->height() - _mirrorViewRect.y() - _mirrorViewRect.height(), 
+                        _mirrorViewRect.width(), _mirrorViewRect.height());
+            glScissor(_mirrorViewRect.x(), _glWidget->height() - _mirrorViewRect.y() - _mirrorViewRect.height(), 
+                        _mirrorViewRect.width(), _mirrorViewRect.height());
             bool updateViewFrustum = false;
             updateProjectionMatrix(_mirrorCamera, updateViewFrustum);
             glEnable(GL_SCISSOR_TEST);
@@ -506,7 +512,6 @@ void Application::paintGL() {
                 // restore absolute translations
                 _myAvatar.getSkeletonModel().setTranslation(absoluteSkeletonTranslation);
                 _myAvatar.getHead().getFaceModel().setTranslation(absoluteFaceTranslation);
-                
             } else {
                 displaySide(_mirrorCamera, true);
             }
@@ -531,7 +536,8 @@ void Application::paintGL() {
 void Application::resetCamerasOnResizeGL(Camera& camera, int width, int height) {
     if (OculusManager::isConnected()) {
         OculusManager::configureCamera(camera, width, height);
-        
+    } else if (TV3DManager::isConnected()) {
+        TV3DManager::configureCamera(camera, width, height);
     } else {
         camera.setAspectRatio((float)width / height);
         camera.setFieldOfView(Menu::getInstance()->getFieldOfView());
@@ -910,7 +916,9 @@ void Application::keyPressEvent(QKeyEvent* event) {
             case Qt::Key_J:
                 if (isShifted) {
                     _viewFrustum.setFocalLength(_viewFrustum.getFocalLength() - 0.1f);
-                
+                    if (TV3DManager::isConnected()) {
+                        TV3DManager::configureCamera(_myCamera, _glWidget->width(),_glWidget->height());
+                    }
                 } else {
                     _myCamera.setEyeOffsetPosition(_myCamera.getEyeOffsetPosition() + glm::vec3(-0.001, 0, 0));
                 }
@@ -920,6 +928,9 @@ void Application::keyPressEvent(QKeyEvent* event) {
             case Qt::Key_M:
                 if (isShifted) {
                     _viewFrustum.setFocalLength(_viewFrustum.getFocalLength() + 0.1f);
+                    if (TV3DManager::isConnected()) {
+                        TV3DManager::configureCamera(_myCamera, _glWidget->width(),_glWidget->height());
+                    }
                 
                 } else {
                     _myCamera.setEyeOffsetPosition(_myCamera.getEyeOffsetPosition() + glm::vec3(0.001, 0, 0));
@@ -1839,6 +1850,13 @@ void Application::init() {
                                   "trigger",
                                   Qt::QueuedConnection);
     }
+
+    TV3DManager::connect();
+    if (TV3DManager::isConnected()) {
+        QMetaObject::invokeMethod(Menu::getInstance()->getActionForOption(MenuOption::Fullscreen),
+                                  "trigger",
+                                  Qt::QueuedConnection);
+    }
     
     LeapManager::initialize();
     
@@ -2426,7 +2444,7 @@ void Application::updateCamera(float deltaTime) {
     bool showWarnings = Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings);
     PerformanceWarning warn(showWarnings, "Application::updateCamera()");
 
-    if (!OculusManager::isConnected()) {        
+    if (!OculusManager::isConnected() && !TV3DManager::isConnected()) {        
         if (Menu::getInstance()->isOptionChecked(MenuOption::FullscreenMirror)) {
             if (_myCamera.getMode() != CAMERA_MODE_MIRROR) {
                 _myCamera.setMode(CAMERA_MODE_MIRROR);
@@ -3811,7 +3829,7 @@ void Application::renderAvatars(bool forceRenderHead, bool selfAvatarOnly) {
         return;
     }
     PerformanceWarning warn(Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings), 
-        "Application::displaySide() ... Avatars...");
+        "Application::renderAvatars()");
 
     if (!selfAvatarOnly) {
         //  Render avatars of other nodes
@@ -4100,7 +4118,7 @@ void Application::resetSensors() {
     if (OculusManager::isConnected()) {
         OculusManager::reset();
     }
-    
+
     QCursor::setPos(_headMouseX, _headMouseY);
     _myAvatar.reset();
     _myTransmitter.resetLevels();
diff --git a/interface/src/Application.h b/interface/src/Application.h
index e917f6d63d..fac4d03fb2 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -254,7 +254,6 @@ private slots:
     void shrinkMirrorView();
     void resetSensors();
 
-
 private:
     void resetCamerasOnResizeGL(Camera& camera, int width, int height);
     void updateProjectionMatrix();
diff --git a/interface/src/Menu.cpp b/interface/src/Menu.cpp
index 98b807fea2..286959d413 100644
--- a/interface/src/Menu.cpp
+++ b/interface/src/Menu.cpp
@@ -232,6 +232,8 @@ Menu::Menu() :
     addCheckableActionToQMenuAndActionHash(viewMenu, MenuOption::FirstPerson, Qt::Key_P, true);
     addCheckableActionToQMenuAndActionHash(viewMenu, MenuOption::Mirror, Qt::SHIFT | Qt::Key_H);
     addCheckableActionToQMenuAndActionHash(viewMenu, MenuOption::FullscreenMirror, Qt::Key_H);
+    addCheckableActionToQMenuAndActionHash(viewMenu, MenuOption::Enable3DTVMode, 0, false);
+    
     
     QMenu* avatarSizeMenu = viewMenu->addMenu("Avatar Size");
     
diff --git a/interface/src/Menu.h b/interface/src/Menu.h
index 73bb0472b4..f5b41d904e 100644
--- a/interface/src/Menu.h
+++ b/interface/src/Menu.h
@@ -178,6 +178,7 @@ namespace MenuOption {
     const QString FilterSixense = "Smooth Sixense Movement";
     const QString DontRenderVoxels = "Don't call _voxels.render()";
     const QString DontCallOpenGLForVoxels = "Don't call glDrawRangeElementsEXT() for Voxels";
+    const QString Enable3DTVMode = "Enable 3DTV Mode";
     const QString EnableOcclusionCulling = "Enable Occlusion Culling";
     const QString EnableVoxelPacketCompression = "Enable Voxel Packet Compression";
     const QString EchoServerAudio = "Echo Server Audio";
diff --git a/interface/src/avatar/Hand.cpp b/interface/src/avatar/Hand.cpp
index 6d71cd2aef..5f712d947b 100644
--- a/interface/src/avatar/Hand.cpp
+++ b/interface/src/avatar/Hand.cpp
@@ -127,12 +127,12 @@ void Hand::simulateToyBall(PalmData& palm, const glm::vec3& fingerTipPosition, f
             //printf(">>>>>>> caught... handID:%d particle ID:%d _toyBallInHand[handID] = true\n", handID, closestParticle->getID());
             _ballParticleEditHandles[handID] = caughtParticle;
             caughtParticle = NULL;
-            //  Play a catch sound!
+            
+            // set the position of the catch sound to the new position of the ball
             _catchInjector.setPosition(targetPosition);
             
             // inject the catch sound to the mixer and play it locally
             _catchInjector.injectViaThread(app->getAudio());
-            app->getAudio()->startDrumSound(1.0, 300, 0.75, 0.015);
         }
     }
     
diff --git a/interface/src/devices/TV3DManager.cpp b/interface/src/devices/TV3DManager.cpp
new file mode 100644
index 0000000000..283b9f3e37
--- /dev/null
+++ b/interface/src/devices/TV3DManager.cpp
@@ -0,0 +1,132 @@
+//
+//  TV3DManager.cpp
+//  hifi
+//
+//  Created by Brad Hefta-Gaub on 12/24/13.
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+#include <QOpenGLFramebufferObject>
+
+#include <glm/glm.hpp>
+
+#include "Application.h"
+#include "InterfaceConfig.h"
+#include "TV3DManager.h"
+#include "Menu.h"
+
+int TV3DManager::_screenWidth = 1;
+int TV3DManager::_screenHeight = 1;
+double TV3DManager::_aspect = 1.0;
+eyeFrustum TV3DManager::_leftEye;
+eyeFrustum TV3DManager::_rightEye;
+
+
+bool TV3DManager::isConnected() {
+    return Menu::getInstance()->isOptionChecked(MenuOption::Enable3DTVMode);
+}
+
+void TV3DManager::connect() {
+    Application* app = Application::getInstance();
+    int width = app->getGLWidget()->width();
+    int height = app->getGLWidget()->height();
+    Camera& camera = *app->getCamera();
+
+    configureCamera(camera, width, height);
+}
+
+
+// The basic strategy of this stereoscopic rendering is explained here:
+//    http://www.orthostereo.com/geometryopengl.html
+void TV3DManager::setFrustum(Camera& whichCamera) {
+    const double DTR = 0.0174532925; // degree to radians
+    const double IOD = 0.05; //intraocular distance
+    double fovy = whichCamera.getFieldOfView(); // field of view in y-axis
+    double nearZ = whichCamera.getNearClip(); // near clipping plane
+    double screenZ = Application::getInstance()->getViewFrustum()->getFocalLength(); // screen projection plane
+
+    double top = nearZ * tan(DTR * fovy / 2); //sets top of frustum based on fovy and near clipping plane
+    double right = _aspect * top; // sets right of frustum based on aspect ratio
+    double frustumshift = (IOD / 2) * nearZ / screenZ;
+    
+    _leftEye.top = top;
+    _leftEye.bottom = -top;
+    _leftEye.left = -right + frustumshift;
+    _leftEye.right = right + frustumshift;
+    _leftEye.modelTranslation = IOD / 2;
+    
+    _rightEye.top = top;
+    _rightEye.bottom = -top;
+    _rightEye.left = -right - frustumshift;
+    _rightEye.right = right - frustumshift;
+    _rightEye.modelTranslation = -IOD / 2;
+}
+
+void TV3DManager::configureCamera(Camera& whichCamera, int screenWidth, int screenHeight) {
+    if (screenHeight == 0) {
+        screenHeight = 1; // prevent divide by 0
+    }
+    _screenWidth = screenWidth;
+    _screenHeight = screenHeight;
+    _aspect= (double)_screenWidth / (double)_screenHeight;
+    setFrustum(whichCamera);
+
+    glViewport (0, 0, _screenWidth, _screenHeight); // sets drawing viewport
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+}
+
+void TV3DManager::display(Camera& whichCamera) {
+    double nearZ = whichCamera.getNearClip(); // near clipping plane
+    double farZ = whichCamera.getFarClip(); // far clipping plane
+
+    // left eye portal
+    int portalX = 0;
+    int portalY = 0;
+    int portalW = Application::getInstance()->getGLWidget()->width() / 2;
+    int portalH = Application::getInstance()->getGLWidget()->height();
+
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+    glEnable(GL_SCISSOR_TEST);
+    // render left side view
+    glViewport(portalX, portalY, portalW, portalH);
+    glScissor(portalX, portalY, portalW, portalH);
+
+    glPushMatrix();
+    {
+        glMatrixMode(GL_PROJECTION);
+        glLoadIdentity(); // reset projection matrix
+        glFrustum(_leftEye.left, _leftEye.right, _leftEye.bottom, _leftEye.top, nearZ, farZ); // set left view frustum
+        glTranslatef(_leftEye.modelTranslation, 0.0, 0.0); // translate to cancel parallax
+        glMatrixMode(GL_MODELVIEW);
+        glLoadIdentity();
+        Application::getInstance()->displaySide(whichCamera);
+    }
+    glPopMatrix();
+    glDisable(GL_SCISSOR_TEST);
+
+    // render right side view
+    portalX = Application::getInstance()->getGLWidget()->width() / 2;
+    glEnable(GL_SCISSOR_TEST);
+    // render left side view
+    glViewport(portalX, portalY, portalW, portalH);
+    glScissor(portalX, portalY, portalW, portalH);
+    glPushMatrix();
+    {
+        glMatrixMode(GL_PROJECTION);
+        glLoadIdentity(); // reset projection matrix
+        glFrustum(_rightEye.left, _rightEye.right, _rightEye.bottom, _rightEye.top, nearZ, farZ); // set left view frustum
+        glTranslatef(_rightEye.modelTranslation, 0.0, 0.0); // translate to cancel parallax
+        glMatrixMode(GL_MODELVIEW);
+        glLoadIdentity();
+        Application::getInstance()->displaySide(whichCamera);
+    }
+    glPopMatrix();
+    glDisable(GL_SCISSOR_TEST);
+
+    // reset the viewport to how we started
+    glViewport(0, 0, Application::getInstance()->getGLWidget()->width(), Application::getInstance()->getGLWidget()->height());
+}
\ No newline at end of file
diff --git a/interface/src/devices/TV3DManager.h b/interface/src/devices/TV3DManager.h
new file mode 100644
index 0000000000..edea489745
--- /dev/null
+++ b/interface/src/devices/TV3DManager.h
@@ -0,0 +1,41 @@
+//
+//  TV3DManager.h
+//  hifi
+//
+//  Created by Brad Hefta-Gaub on 12/24/2013
+//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
+//
+
+#ifndef __hifi__TV3DManager__
+#define __hifi__TV3DManager__
+
+#include <iostream>
+
+class Camera;
+
+struct eyeFrustum {
+    double left;
+    double right;
+    double bottom;
+    double top;
+    float modelTranslation;
+};
+
+
+/// Handles interaction with 3D TVs
+class TV3DManager {
+public:
+    static void connect();
+    static bool isConnected();
+    static void configureCamera(Camera& camera, int screenWidth, int screenHeight);
+    static void display(Camera& whichCamera);
+private:    
+    static void setFrustum(Camera& whichCamera);
+    static int _screenWidth;
+    static int _screenHeight;
+    static double _aspect;
+    static eyeFrustum _leftEye;
+    static eyeFrustum _rightEye;
+};
+
+#endif /* defined(__hifi__TV3DManager__) */
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index 7ebf12616d..1dd5dacafe 100755
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -41,6 +41,8 @@ enum KeyState
     DELETE_KEY_DOWN
 };
 
+const glm::vec3 vec3Zero(0.0f);
+
 class JointData;
 
 class AvatarData : public NodeData {
@@ -103,6 +105,17 @@ public:
 
     void setHeadData(HeadData* headData) { _headData = headData; }
     void setHandData(HandData* handData) { _handData = handData; }
+
+    virtual const glm::vec3& getVelocity() const { return vec3Zero; }
+
+    /// Checks for penetration between the described sphere and the avatar.
+    /// \param penetratorCenter the center of the penetration test sphere
+    /// \param penetratorRadius the radius of the penetration test sphere
+    /// \param penetration[out] the vector in which to store the penetration
+    /// \param skeletonSkipIndex if not -1, the index of a joint to skip (along with its descendents) in the skeleton model
+    /// \return whether or not the sphere penetrated
+    virtual bool findSpherePenetration(const glm::vec3& penetratorCenter, float penetratorRadius,
+        glm::vec3& penetration, int skeletonSkipIndex = -1) { return false; }
     
 protected:
     QUuid _uuid;
diff --git a/libraries/octree/src/Octree.cpp b/libraries/octree/src/Octree.cpp
index 56bbc79bda..3f50776443 100644
--- a/libraries/octree/src/Octree.cpp
+++ b/libraries/octree/src/Octree.cpp
@@ -572,7 +572,7 @@ bool findRayIntersectionOp(OctreeElement* node, void* extraData) {
 
 bool Octree::findRayIntersection(const glm::vec3& origin, const glm::vec3& direction,
                                     OctreeElement*& node, float& distance, BoxFace& face) {
-    RayArgs args = { origin / (float)TREE_SCALE, direction, node, distance, face };
+    RayArgs args = { origin / static_cast<float>(TREE_SCALE), direction, node, distance, face };
     recurseTreeWithOperation(findRayIntersectionOp, &args);
     return args.found;
 }
@@ -600,7 +600,7 @@ bool findSpherePenetrationOp(OctreeElement* element, void* extraData) {
     if (element->hasContent()) {
         glm::vec3 elementPenetration;
         if (element->findSpherePenetration(args->center, args->radius, elementPenetration, &args->penetratedObject)) {
-            args->penetration = addPenetrations(args->penetration, elementPenetration * (float)TREE_SCALE);
+            args->penetration = addPenetrations(args->penetration, elementPenetration * static_cast<float>(TREE_SCALE));
             args->found = true;
         }
     }
@@ -610,7 +610,12 @@ bool findSpherePenetrationOp(OctreeElement* element, void* extraData) {
 bool Octree::findSpherePenetration(const glm::vec3& center, float radius, glm::vec3& penetration, 
                     void** penetratedObject) {
                     
-    SphereArgs args = { center / (float)TREE_SCALE, radius / TREE_SCALE, penetration, false, NULL };
+    SphereArgs args = { 
+        center / static_cast<float>(TREE_SCALE), 
+        radius / static_cast<float>(TREE_SCALE), 
+        penetration, 
+        false, 
+        NULL };
     penetration = glm::vec3(0.0f, 0.0f, 0.0f);
     recurseTreeWithOperation(findSpherePenetrationOp, &args);
     if (penetratedObject) {
@@ -642,7 +647,7 @@ bool findCapsulePenetrationOp(OctreeElement* node, void* extraData) {
     if (node->hasContent()) {
         glm::vec3 nodePenetration;
         if (box.findCapsulePenetration(args->start, args->end, args->radius, nodePenetration)) {
-            args->penetration = addPenetrations(args->penetration, nodePenetration * (float)TREE_SCALE);
+            args->penetration = addPenetrations(args->penetration, nodePenetration * static_cast<float>(TREE_SCALE));
             args->found = true;
         }
     }
@@ -650,7 +655,11 @@ bool findCapsulePenetrationOp(OctreeElement* node, void* extraData) {
 }
 
 bool Octree::findCapsulePenetration(const glm::vec3& start, const glm::vec3& end, float radius, glm::vec3& penetration) {
-    CapsuleArgs args = { start / (float)TREE_SCALE, end / (float)TREE_SCALE, radius / TREE_SCALE, penetration };
+    CapsuleArgs args = { 
+        start / static_cast<float>(TREE_SCALE), 
+        end / static_cast<float>(TREE_SCALE), 
+        radius / static_cast<float>(TREE_SCALE), 
+        penetration };
     penetration = glm::vec3(0.0f, 0.0f, 0.0f);
     recurseTreeWithOperation(findCapsulePenetrationOp, &args);
     return args.found;
@@ -719,8 +728,8 @@ int Octree::encodeTreeBitstream(OctreeElement* node,
     // if childBytesWritten == 1 then something went wrong... that's not possible
     assert(childBytesWritten != 1);
 
-    // if includeColor and childBytesWritten == 2, then it can only mean that the lower level trees don't exist or for some reason
-    // couldn't be written... so reset them here... This isn't true for the non-color included case
+    // if includeColor and childBytesWritten == 2, then it can only mean that the lower level trees don't exist or for some 
+    // reason couldn't be written... so reset them here... This isn't true for the non-color included case
     if (params.includeColor && childBytesWritten == 2) {
         childBytesWritten = 0;
         //params.stopReason = EncodeBitstreamParams::UNKNOWN; // possibly should be DIDNT_FIT...
@@ -887,9 +896,10 @@ int Octree::encodeTreeBitstreamRecursion(OctreeElement* node,
     bool keepDiggingDeeper = true; // Assuming we're in view we have a great work ethic, we're always ready for more!
 
     // At any given point in writing the bitstream, the largest minimum we might need to flesh out the current level
-    // is 1 byte for child colors + 3*NUMBER_OF_CHILDREN bytes for the actual colors + 1 byte for child trees. There could be sub trees
-    // below this point, which might take many more bytes, but that's ok, because we can always mark our subtrees as
-    // not existing and stop the packet at this point, then start up with a new packet for the remaining sub trees.
+    // is 1 byte for child colors + 3*NUMBER_OF_CHILDREN bytes for the actual colors + 1 byte for child trees. 
+    // There could be sub trees below this point, which might take many more bytes, but that's ok, because we can 
+    // always mark our subtrees as not existing and stop the packet at this point, then start up with a new packet 
+    // for the remaining sub trees.
     unsigned char childrenExistInTreeBits = 0;
     unsigned char childrenExistInPacketBits = 0;
     unsigned char childrenColoredBits = 0;
@@ -943,7 +953,6 @@ int Octree::encodeTreeBitstreamRecursion(OctreeElement* node,
         if (params.stats && childNode) {
             params.stats->traversed(childNode);
         }
-    
     }
 
     // for each child node in Distance sorted order..., check to see if they exist, are colored, and in view, and if so
@@ -1066,7 +1075,6 @@ int Octree::encodeTreeBitstreamRecursion(OctreeElement* node,
                                 params.stats->skippedNoChange(childNode);
                             }
                         }
-                        
                     }
                 }
             }
diff --git a/libraries/particles/src/Particle.cpp b/libraries/particles/src/Particle.cpp
index 2e4a341d4d..d07f5a7889 100644
--- a/libraries/particles/src/Particle.cpp
+++ b/libraries/particles/src/Particle.cpp
@@ -466,15 +466,14 @@ void Particle::adjustEditPacketForClockSkew(unsigned char* codeColorBuffer, ssiz
 
 
 void Particle::update() {
-
     uint64_t now = usecTimestampNow();
-    int elapsed = now - _lastUpdated; // making this signed slightly improves clock skew behavior
-    float timeElapsed = (float)((float)elapsed/(float)USECS_PER_SECOND);
-    
+    float elapsed = static_cast<float>(now - _lastUpdated);
+    _lastUpdated = now;
+    float timeElapsed = elapsed / static_cast<float>(USECS_PER_SECOND);
     
     // calculate our default shouldDie state... then allow script to change it if it wants...
     float velocityScalar = glm::length(getVelocity());
-    const float STILL_MOVING = 0.05 / TREE_SCALE;
+    const float STILL_MOVING = 0.05f / static_cast<float>(TREE_SCALE);
     bool isStillMoving = (velocityScalar > STILL_MOVING);
     const float REALLY_OLD = 30.0f; // 30 seconds
     bool isReallyOld = (getLifetime() > REALLY_OLD);
@@ -510,8 +509,6 @@ void Particle::update() {
         _velocity -= dampingResistance * timeElapsed;
         //printf("applying damping to Particle timeElapsed=%f\n",timeElapsed);
     }
-    
-    _lastUpdated = now;
 }
 
 void Particle::runUpdateScript() {
diff --git a/libraries/particles/src/Particle.h b/libraries/particles/src/Particle.h
index 06709b4c06..9c92d0ec48 100644
--- a/libraries/particles/src/Particle.h
+++ b/libraries/particles/src/Particle.h
@@ -79,8 +79,8 @@ public:
     uint64_t getLastEdited() const { return _lastEdited; }
 
     /// lifetime of the particle in seconds
-    float getLifetime() const { return (float)(usecTimestampNow() - _created) / (float)USECS_PER_SECOND; }
-    float getEditedAgo() const { return (float)(usecTimestampNow() - _lastEdited) / (float)USECS_PER_SECOND; }
+    float getLifetime() const { return static_cast<float>(usecTimestampNow() - _created) / static_cast<float>(USECS_PER_SECOND); }
+    float getEditedAgo() const { return static_cast<float>(usecTimestampNow() - _lastEdited) / static_cast<float>(USECS_PER_SECOND); }
     uint32_t getID() const { return _id; }
     bool getShouldDie() const { return _shouldDie; }
     QString getScript() const { return _script; }
diff --git a/libraries/particles/src/ParticleCollisionSystem.cpp b/libraries/particles/src/ParticleCollisionSystem.cpp
index 0a9b8ea1e2..173bd0738b 100644
--- a/libraries/particles/src/ParticleCollisionSystem.cpp
+++ b/libraries/particles/src/ParticleCollisionSystem.cpp
@@ -67,10 +67,10 @@ void ParticleCollisionSystem::checkParticle(Particle* particle) {
 }
 
 void ParticleCollisionSystem::updateCollisionWithVoxels(Particle* particle) {
-    glm::vec3 center = particle->getPosition() * (float)TREE_SCALE;
-    float radius = particle->getRadius() * (float)TREE_SCALE;
-    const float VOXEL_ELASTICITY = 1.4f;
-    const float VOXEL_DAMPING = 0.0;
+    glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
+    float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
+    const float VOXEL_ELASTICITY = 0.4f;    // fraction of momentum conserved at collision
+    const float VOXEL_DAMPING = 0.0f;
     const float VOXEL_COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     VoxelDetail* voxelDetails = NULL;
@@ -88,10 +88,10 @@ void ParticleCollisionSystem::updateCollisionWithVoxels(Particle* particle) {
 }
 
 void ParticleCollisionSystem::updateCollisionWithParticles(Particle* particle) {
-    glm::vec3 center = particle->getPosition() * (float)TREE_SCALE;
-    float radius = particle->getRadius() * (float)TREE_SCALE;
+    glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
+    float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
     const float VOXEL_ELASTICITY = 1.4f;
-    const float VOXEL_DAMPING = 0.0;
+    const float VOXEL_DAMPING = 0.0f;
     const float VOXEL_COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     Particle* penetratedParticle;
@@ -132,10 +132,10 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
     }
 
     //printf("updateCollisionWithAvatars()...\n");
-    glm::vec3 center = particle->getPosition() * (float)TREE_SCALE;
-    float radius = particle->getRadius() * (float)TREE_SCALE;
+    glm::vec3 center = particle->getPosition() * static_cast<float>(TREE_SCALE);
+    float radius = particle->getRadius() * static_cast<float>(TREE_SCALE);
     const float VOXEL_ELASTICITY = 1.4f;
-    const float VOXEL_DAMPING = 0.0;
+    const float VOXEL_DAMPING = 0.0f;
     const float VOXEL_COLLISION_FREQUENCY = 0.5f;
     glm::vec3 penetration;
     const PalmData* collidingPalm = NULL;
@@ -144,23 +144,34 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
     if (_selfAvatar) {
         AvatarData* avatar = (AvatarData*)_selfAvatar;
         //printf("updateCollisionWithAvatars()..._selfAvatar=%p\n", avatar);
-        
+
         // check hands...
         const HandData* handData = avatar->getHandData();
 
-        // if the particle penetrates the hand, then apply a hard collision
+        // TODO: combine hand and collision check into one.  Note: would need to supply
+        // CollisionInfo class rather than just vec3 (penetration) so we can get back
+        // added velocity.
+
         if (handData->findSpherePenetration(center, radius, penetration, collidingPalm)) {
+            // TODO: dot collidingPalm and hand velocities and skip collision when they are moving apart.
+            // apply a hard collision when ball collides with hand
             penetration /= (float)TREE_SCALE;
             updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
     
             // determine if the palm that collided was moving, if so, then we add that palm velocity as well...
             glm::vec3 addedVelocity = NO_ADDED_VELOCITY;
             if (collidingPalm) {
-                glm::vec3 palmVelocity = collidingPalm->getVelocity() / (float)TREE_SCALE;
+                glm::vec3 palmVelocity = collidingPalm->getVelocity() / static_cast<float>(TREE_SCALE);
                 //printf("collidingPalm Velocity=%f,%f,%f\n", palmVelocity.x, palmVelocity.y, palmVelocity.z);
                 addedVelocity = palmVelocity;
             }
 
+            applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
+        } else if (avatar->findSpherePenetration(center, radius, penetration)) {
+            // apply hard collision when particle collides with avatar
+            penetration /= (float)TREE_SCALE;
+            updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
+            glm::vec3 addedVelocity = avatar->getVelocity();
             applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
         }
     }
@@ -170,27 +181,33 @@ void ParticleCollisionSystem::updateCollisionWithAvatars(Particle* particle) {
     for (NodeList::iterator node = nodeList->begin(); node != nodeList->end(); node++) {
         //qDebug() << "updateCollisionWithAvatars()... node:" << *node << "\n";
         if (node->getLinkedData() && node->getType() == NODE_TYPE_AGENT) {
-            AvatarData* avatar = (AvatarData*)node->getLinkedData();
+            // TODO: dot collidingPalm and hand velocities and skip collision when they are moving apart.
+            AvatarData* avatar = static_cast<AvatarData*>(node->getLinkedData());
             //printf("updateCollisionWithAvatars()...avatar=%p\n", avatar);
             
             // check hands...
             const HandData* handData = avatar->getHandData();
 
-            // if the particle penetrates the hand, then apply a hard collision
             if (handData->findSpherePenetration(center, radius, penetration, collidingPalm)) {
+                // apply a hard collision when ball collides with hand
                 penetration /= (float)TREE_SCALE;
                 updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
 
                 // determine if the palm that collided was moving, if so, then we add that palm velocity as well...
                 glm::vec3 addedVelocity = NO_ADDED_VELOCITY;
                 if (collidingPalm) {
-                    glm::vec3 palmVelocity = collidingPalm->getVelocity() / (float)TREE_SCALE;
+                    glm::vec3 palmVelocity = collidingPalm->getVelocity() / static_cast<float>(TREE_SCALE);
                     //printf("collidingPalm Velocity=%f,%f,%f\n", palmVelocity.x, palmVelocity.y, palmVelocity.z);
                     addedVelocity = palmVelocity;
                 }
 
                 applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
 
+            } else if (avatar->findSpherePenetration(center, radius, penetration)) {
+                penetration /= (float)TREE_SCALE;
+                updateCollisionSound(particle, penetration, VOXEL_COLLISION_FREQUENCY);
+                glm::vec3 addedVelocity = avatar->getVelocity();
+                applyHardCollision(particle, penetration, VOXEL_ELASTICITY, VOXEL_DAMPING, addedVelocity);
             }
         }
     }
@@ -203,21 +220,22 @@ void ParticleCollisionSystem::applyHardCollision(Particle* particle, const glm::
     //  Update the particle in response to a hard collision.  Position will be reset exactly
     //  to outside the colliding surface.  Velocity will be modified according to elasticity.
     //
-    //  if elasticity = 1.0, collision is inelastic.
-    //  if elasticity > 1.0, collision is elastic. 
+    //  if elasticity = 0.0, collision is inelastic (vel normal to collision is lost)
+    //  if elasticity = 1.0, collision is 100% elastic. 
     //  
     glm::vec3 position = particle->getPosition();
     glm::vec3 velocity = particle->getVelocity();
 
-    position -= penetration;
-    static float HALTING_VELOCITY = 0.2f / (float) TREE_SCALE;
-    // cancel out the velocity component in the direction of penetration
-    float penetrationLength = glm::length(penetration);
     const float EPSILON = 0.0f;
+    float velocityDotPenetration = glm::dot(velocity, penetration);
+    if (velocityDotPenetration > EPSILON) {
+        position -= penetration;
+        static float HALTING_VELOCITY = 0.2f / static_cast<float>(TREE_SCALE);
+        // cancel out the velocity component in the direction of penetration
 
-    if (penetrationLength > EPSILON) {
+        float penetrationLength = glm::length(penetration);
         glm::vec3 direction = penetration / penetrationLength;
-        velocity -= glm::dot(velocity, direction) * direction * elasticity;
+        velocity -= (glm::dot(velocity, direction) * (1.0f + elasticity)) * direction;
         velocity += addedVelocity;
         velocity *= glm::clamp(1.f - damping, 0.0f, 1.0f);
         if (glm::length(velocity) < HALTING_VELOCITY) {
@@ -235,7 +253,7 @@ void ParticleCollisionSystem::applyHardCollision(Particle* particle, const glm::
     particleEditHandle.updateParticle(position, particle->getRadius(), particle->getXColor(), velocity,
                            particle->getGravity(), particle->getDamping(), particle->getInHand(), particle->getScript());
 }
-
+    
 
 void ParticleCollisionSystem::updateCollisionSound(Particle* particle, const glm::vec3 &penetration, float frequency) {
                                 
@@ -244,12 +262,12 @@ void ParticleCollisionSystem::updateCollisionSound(Particle* particle, const glm
     const float COLLISION_LOUDNESS = 1.f;
     const float DURATION_SCALING = 0.004f;
     const float NOISE_SCALING = 0.1f;
-    glm::vec3 velocity = particle->getVelocity() * (float)TREE_SCALE;
+    glm::vec3 velocity = particle->getVelocity() * static_cast<float>(TREE_SCALE);
 
     /*
     // how do we want to handle this??
     //
-     glm::vec3 gravity = particle->getGravity() * (float)TREE_SCALE;
+     glm::vec3 gravity = particle->getGravity() * static_cast<float>(TREE_SCALE);
     
     if (glm::length(gravity) > EPSILON) {
         //  If gravity is on, remove the effect of gravity on velocity for this
@@ -271,4 +289,4 @@ void ParticleCollisionSystem::updateCollisionSound(Particle* particle, const glm
                     fmin(velocityTangentToCollision / velocityTowardCollision * NOISE_SCALING, 1.f),
                     1.f - DURATION_SCALING * powf(frequency, 0.5f) / velocityTowardCollision, false);
     }
-}
\ No newline at end of file
+}
diff --git a/libraries/shared/src/NodeList.cpp b/libraries/shared/src/NodeList.cpp
index cded2f7d4e..c763a52e05 100644
--- a/libraries/shared/src/NodeList.cpp
+++ b/libraries/shared/src/NodeList.cpp
@@ -294,9 +294,9 @@ void NodeList::clear() {
         Node* node = nodeBucket[i % NODES_PER_BUCKET];
         
         node->lock();
-        delete node;
+        notifyHooksOfKilledNode(&*node);
         
-        node = NULL;
+        delete node;
     }
     
     _numNodes = 0;