fix for flickering avatars

interface/src/avatar/Avatar.cpp

@@ -50,7 +50,7 @@ Avatar::Avatar() :
     AvatarData(),
     _skeletonModel(this),
     _bodyYawDelta(0.0f),
-    _lastPosition(0.0f),
+    _lastPosition(_position),
     _velocity(0.0f),
     _lastVelocity(0.0f),
     _acceleration(0.0f),
@@ -204,7 +204,9 @@ void Avatar::simulate(float deltaTime) {
         _displayNameAlpha = abs(_displayNameAlpha - _displayNameTargetAlpha) < 0.01f ? _displayNameTargetAlpha : _displayNameAlpha;
     }
 
-    _position += _velocity * deltaTime;
+    // NOTE: we shouldn't extrapolate an Avatar instance forward in time... 
+    // until velocity is in AvatarData update message.
+    //_position += _velocity * deltaTime;
     measureMotionDerivatives(deltaTime);
 }
 
@@ -223,20 +225,6 @@ void Avatar::measureMotionDerivatives(float deltaTime) {
     _lastOrientation = getOrientation();
 }
 
-void Avatar::setPosition(const glm::vec3 position, bool overideReferential) {
-    AvatarData::setPosition(position, overideReferential);
-    _lastPosition = position;
-    _velocity = glm::vec3(0.0f);
-    _lastVelocity = glm::vec3(0.0f);
-}
-
-void Avatar::slamPosition(const glm::vec3& newPosition) {
-    _position = newPosition;
-    _lastPosition = newPosition;
-    _velocity = glm::vec3(0.0f);
-    _lastVelocity = glm::vec3(0.0f);
-}
-
 void Avatar::setMouseRay(const glm::vec3 &origin, const glm::vec3 &direction) {
     _mouseRayOrigin = origin;
     _mouseRayDirection = direction;

interface/src/avatar/Avatar.h

@@ -161,9 +161,6 @@ public:
     /// \param vector position to be scaled. Will store the result
     void scaleVectorRelativeToPosition(glm::vec3 &positionToScale) const;
 
-    void setPosition(const glm::vec3 position, bool overideReferential = false);
-    void slamPosition(const glm::vec3& newPosition);
-    
 public slots:
     void updateCollisionGroups();
     

interface/src/avatar/MyAvatar.cpp

@@ -609,6 +609,13 @@ void MyAvatar::setGravity(const glm::vec3& gravity) {
     // so it continues to point opposite to the previous gravity setting.
 }
 
+void MyAvatar::slamPosition(const glm::vec3& newPosition) {
+    AvatarData::setPosition(newPosition);
+    _lastPosition = _position;
+    _velocity = glm::vec3(0.0f);
+    _lastVelocity = glm::vec3(0.0f); 
+}
+
 AnimationHandlePointer MyAvatar::addAnimationHandle() {
     AnimationHandlePointer handle = _skeletonModel.createAnimationHandle();
     _animationHandles.append(handle);
@@ -797,9 +804,11 @@ void MyAvatar::loadData(QSettings* settings) {
 
     getHead()->setBasePitch(loadSetting(settings, "headPitch", 0.0f));
 
-    _position.x = loadSetting(settings, "position_x", START_LOCATION.x);
+    glm::vec3 newPosition;
-    _position.y = loadSetting(settings, "position_y", START_LOCATION.y);
+    newPosition.x = loadSetting(settings, "position_x", START_LOCATION.x);
-    _position.z = loadSetting(settings, "position_z", START_LOCATION.z);
+    newPosition.y = loadSetting(settings, "position_y", START_LOCATION.y);
+    newPosition.z = loadSetting(settings, "position_z", START_LOCATION.z);
+    slamPosition(newPosition);
 
     getHead()->setPupilDilation(loadSetting(settings, "pupilDilation", 0.0f));
 

interface/src/avatar/MyAvatar.h

@@ -57,6 +57,7 @@ public:
     void setLeanScale(float scale) { _leanScale = scale; }
     void setLocalGravity(glm::vec3 gravity);
     void setShouldRenderLocally(bool shouldRender) { _shouldRender = shouldRender; }
+    void slamPosition(const glm::vec3& position);
 
     // getters
     float getLeanScale() const { return _leanScale; }

libraries/avatars/src/AvatarData.cpp

@@ -35,7 +35,8 @@ using namespace std;
 
 AvatarData::AvatarData() :
     _sessionUUID(),
-    _handPosition(0,0,0),
+    _position(0.0f),
+    _handPosition(0.0f),
     _referential(NULL),
     _bodyYaw(-90.f),
     _bodyPitch(0.0f),
@@ -326,7 +327,7 @@ int AvatarData::parseDataAtOffset(const QByteArray& packet, int offset) {
             }
             return maxAvailableSize;
         }
-        _position = position;
+        setPosition(position);
         
         // rotation (NOTE: This needs to become a quaternion to save two bytes)
         float yaw, pitch, roll;