From 70664b64eb1becb11ddbee7bc221af8ef832ccd2 Mon Sep 17 00:00:00 2001
From: Bradley Austin Davis <bdavis@saintandreas.org>
Date: Wed, 25 Jan 2017 10:59:49 -0800
Subject: [PATCH 01/17] Attempt to account for sparse texture memory overhead

---
 libraries/gpu-gl/src/gpu/gl45/GL45Backend.h   |  27 +--
 .../src/gpu/gl45/GL45BackendTexture.cpp       | 177 ++----------------
 2 files changed, 21 insertions(+), 183 deletions(-)

diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h b/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
index c338d6e641..2242bba5d9 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
@@ -48,39 +48,18 @@ public:
             void update();
             uvec3 getPageCounts(const uvec3& dimensions) const;
             uint32_t getPageCount(const uvec3& dimensions) const;
+            uint32_t getSize() const;
 
             GL45Texture& texture;
             bool sparse { false };
             uvec3 pageDimensions { DEFAULT_PAGE_DIMENSION };
             GLuint maxSparseLevel { DEFAULT_MAX_SPARSE_LEVEL };
+            uint32_t allocatedPages { 0 };
             uint32_t maxPages { 0 };
             uint32_t pageBytes { 0 };
             GLint pageDimensionsIndex { 0 };
         };
 
-#if INCREMENTAL_TRANSFER
-        struct TransferState {
-            TransferState(GL45Texture& texture);
-            uvec3 currentPageSize() const;
-            void updateMip();
-            void populatePage(std::vector<uint8_t>& dest);
-            bool increment();
-
-            GL45Texture& texture;
-            GLTexelFormat texelFormat;
-            uint8_t face { 0 };
-            uint16_t mipLevel { 0 };
-            uint32_t bytesPerLine { 0 };
-            uint32_t bytesPerPixel { 0 };
-            uint32_t bytesPerPage { 0 };
-            uvec3 mipDimensions;
-            uvec3 mipOffset;
-            const uint8_t* srcPointer { nullptr };
-        };
-    protected:
-        TransferState _transferState;
-#endif
-
     protected:
         void updateMips() override;
         void stripToMip(uint16_t newMinMip);
@@ -98,8 +77,6 @@ public:
         void derez();
 
         SparseInfo _sparseInfo;
-        uint32_t _allocatedPages { 0 };
-        uint32_t _lastMipAllocatedPages { 0 };
         uint16_t _mipOffset { 0 };
         friend class GL45Backend;
     };
diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
index 9b16908244..6632bf936e 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
@@ -116,6 +116,8 @@ void SparseInfo::maybeMakeSparse() {
     }
 }
 
+#define SPARSE_PAGE_SIZE_OVERHEAD_ESTIMATE 1.3f
+
 // This can only be called after we've established our storage size
 void SparseInfo::update() {
     if (!sparse) {
@@ -124,6 +126,9 @@ void SparseInfo::update() {
     glGetTextureParameterIuiv(texture._id, GL_NUM_SPARSE_LEVELS_ARB, &maxSparseLevel);
     pageBytes = texture._gpuObject.getTexelFormat().getSize();
     pageBytes *= pageDimensions.x * pageDimensions.y * pageDimensions.z;
+    // Testing with a simple texture allocating app shows an estimated 20% GPU memory overhead for 
+    // sparse textures as compared to non-sparse, so we acount for that here.
+    pageBytes = (uint32_t)(pageBytes * SPARSE_PAGE_SIZE_OVERHEAD_ESTIMATE);
 
     for (uint16_t mipLevel = 0; mipLevel <= maxSparseLevel; ++mipLevel) {
         auto mipDimensions = texture._gpuObject.evalMipDimensions(mipLevel);
@@ -146,6 +151,11 @@ uint32_t SparseInfo::getPageCount(const uvec3& dimensions) const {
     return pageCounts.x * pageCounts.y * pageCounts.z;
 }
 
+
+uint32_t SparseInfo::getSize() const {
+    return allocatedPages * pageBytes;
+}
+
 void GL45Backend::initTextureManagementStage() {
     // enable the Sparse Texture on gl45
     _textureManagement._sparseCapable = true;
@@ -160,93 +170,6 @@ void GL45Backend::initTextureManagementStage() {
     }
 }
 
-#if INCREMENTAL_TRANSFER
-
-using TransferState = GL45Backend::GL45Texture::TransferState;
-
-TransferState::TransferState(GL45Texture& texture) : texture(texture) {
-}
-
-void TransferState::updateMip() {
-    mipDimensions = texture._gpuObject.evalMipDimensions(mipLevel);
-    mipOffset = uvec3();
-    if (!texture._gpuObject.isStoredMipFaceAvailable(mipLevel, face)) {
-        srcPointer = nullptr;
-        return;
-    }
-
-    auto mip = texture._gpuObject.accessStoredMipFace(mipLevel, face);
-    texelFormat = gl::GLTexelFormat::evalGLTexelFormat(texture._gpuObject.getTexelFormat(), mip->getFormat());
-    srcPointer = mip->readData();
-    bytesPerLine = (uint32_t)mip->getSize() / mipDimensions.y;
-    bytesPerPixel = bytesPerLine / mipDimensions.x;
-}
-
-bool TransferState::increment() {
-    const SparseInfo& sparse = texture._sparseInfo;
-    if ((mipOffset.x + sparse.pageDimensions.x) < mipDimensions.x) {
-        mipOffset.x += sparse.pageDimensions.x;
-        return true;
-    }
-
-    if ((mipOffset.y + sparse.pageDimensions.y) < mipDimensions.y) {
-        mipOffset.x = 0;
-        mipOffset.y += sparse.pageDimensions.y;
-        return true;
-    }
-
-    if (mipOffset.z + sparse.pageDimensions.z < mipDimensions.z) {
-        mipOffset.x = 0;
-        mipOffset.y = 0;
-        ++mipOffset.z;
-        return true;
-    }
-
-    // Done with this mip?, move on to the next mip 
-    if (mipLevel + 1 < texture.usedMipLevels()) {
-        mipOffset = uvec3(0);
-        ++mipLevel;
-        updateMip();
-        return true;
-    }
-
-    uint8_t maxFace = (uint8_t)((texture._target == GL_TEXTURE_CUBE_MAP) ? GLTexture::CUBE_NUM_FACES : 1);
-    uint8_t nextFace = face + 1;
-    // Done with this face?  Move on to the next
-    if (nextFace < maxFace) {
-        ++face;
-        mipOffset = uvec3(0);
-        mipLevel = 0;
-        updateMip();
-        return true;
-    }
-
-    return false;
-}
-
-void TransferState::populatePage(std::vector<uint8_t>& buffer) {
-    uvec3 pageSize = currentPageSize();
-    auto bytesPerPageLine = bytesPerPixel * pageSize.x;
-    if (0 != (bytesPerPageLine % DEFAULT_GL_PIXEL_ALIGNMENT)) {
-        bytesPerPageLine += DEFAULT_GL_PIXEL_ALIGNMENT - (bytesPerPageLine % DEFAULT_GL_PIXEL_ALIGNMENT);
-        assert(0 == (bytesPerPageLine % DEFAULT_GL_PIXEL_ALIGNMENT));
-    }
-    auto totalPageSize = bytesPerPageLine * pageSize.y;
-    if (totalPageSize > buffer.size()) {
-        buffer.resize(totalPageSize);
-    }
-    uint8_t* dst = &buffer[0];
-    for (uint32_t y = 0; y < pageSize.y; ++y) {
-        uint32_t srcOffset = (bytesPerLine * (mipOffset.y + y)) + (bytesPerPixel * mipOffset.x);
-        uint32_t dstOffset = bytesPerPageLine * y;
-        memcpy(dst + dstOffset, srcPointer + srcOffset, pageSize.x * bytesPerPixel);
-    }
-}
-
-uvec3 TransferState::currentPageSize() const {
-    return glm::clamp(mipDimensions - mipOffset, uvec3(1), texture._sparseInfo.pageDimensions);
-}
-#endif
 
 GLuint GL45Texture::allocate(const Texture& texture) {
     GLuint result;
@@ -260,17 +183,11 @@ GLuint GL45Backend::getTextureID(const TexturePointer& texture, bool transfer) {
 
 GL45Texture::GL45Texture(const std::weak_ptr<GLBackend>& backend, const Texture& texture, GLuint externalId)
     : GLTexture(backend, texture, externalId), _sparseInfo(*this) 
-#if INCREMENTAL_TRANSFER
-, _transferState(*this)    
-#endif
 {
 }
 
 GL45Texture::GL45Texture(const std::weak_ptr<GLBackend>& backend, const Texture& texture, bool transferrable)
     : GLTexture(backend, texture, allocate(texture), transferrable), _sparseInfo(*this) 
-#if INCREMENTAL_TRANSFER
-, _transferState(*this)    
-#endif
     {
 
     auto theBackend = _backend.lock();
@@ -316,12 +233,12 @@ GL45Texture::~GL45Texture() {
             });
 
             auto deallocatedPages = _sparseInfo.getPageCount(mipDimensions) * maxFace;
-            assert(deallocatedPages <= _allocatedPages);
-            _allocatedPages -= deallocatedPages;
+            assert(deallocatedPages <= _sparseInfo.allocatedPages);
+            _sparseInfo.allocatedPages -= deallocatedPages;
         }
 
-        if (0 != _allocatedPages) {
-            qCWarning(gpugl45logging) << "Allocated pages remaining " << _id << " " << _allocatedPages;
+        if (0 != _sparseInfo.allocatedPages) {
+            qCWarning(gpugl45logging) << "Allocated pages remaining " << _id << " " << _sparseInfo.allocatedPages;
         }
 
         auto size = _size;
@@ -365,9 +282,9 @@ void GL45Texture::updateSize() const {
     }
 
     if (_transferrable && _sparseInfo.sparse) {
-        auto size = _allocatedPages * _sparseInfo.pageBytes;
+        auto size = _sparseInfo.getSize();
         Backend::updateTextureGPUSparseMemoryUsage(_size, size);
-        setSize(_allocatedPages * _sparseInfo.pageBytes);
+        setSize(size);
     } else {
         setSize(_gpuObject.evalTotalSize(_mipOffset));
     }
@@ -376,20 +293,16 @@ void GL45Texture::updateSize() const {
 void GL45Texture::startTransfer() {
     Parent::startTransfer();
     _sparseInfo.update();
-#if INCREMENTAL_TRANSFER
-    _transferState.updateMip();
-#endif
 }
 
 bool GL45Texture::continueTransfer() {
-#if !INCREMENTAL_TRANSFER
     size_t maxFace = GL_TEXTURE_CUBE_MAP == _target ? CUBE_NUM_FACES : 1;
     for (uint8_t face = 0; face < maxFace; ++face) {
         for (uint16_t mipLevel = _minMip; mipLevel <= _maxMip; ++mipLevel) {
             auto size = _gpuObject.evalMipDimensions(mipLevel);
             if (_sparseInfo.sparse && mipLevel <= _sparseInfo.maxSparseLevel) {
                 glTexturePageCommitmentEXT(_id, mipLevel, 0, 0, face, size.x, size.y, 1, GL_TRUE);
-                _allocatedPages += _sparseInfo.getPageCount(size);
+                _sparseInfo.allocatedPages += _sparseInfo.getPageCount(size);
             }
             if (_gpuObject.isStoredMipFaceAvailable(mipLevel, face)) {
                 auto mip = _gpuObject.accessStoredMipFace(mipLevel, face);
@@ -413,58 +326,6 @@ bool GL45Texture::continueTransfer() {
         }
     }
     return false;
-#else
-    static std::vector<uint8_t> buffer;
-    if (buffer.empty()) {
-        buffer.resize(DEFAULT_PAGE_BUFFER_SIZE);
-    }
-    const uvec3 pageSize = _transferState.currentPageSize();
-    const uvec3& offset = _transferState.mipOffset;
-
-    if (_sparseInfo.sparse && _transferState.mipLevel <= _sparseInfo.maxSparseLevel) {
-        if (_allocatedPages > _sparseInfo.maxPages) {
-            qCWarning(gpugl45logging) << "Exceeded max page allocation!";
-        }
-        glTexturePageCommitmentEXT(_id, _transferState.mipLevel,
-            offset.x, offset.y, _transferState.face,
-            pageSize.x, pageSize.y, pageSize.z,
-            GL_TRUE);
-        ++_allocatedPages;
-    }
-
-    if (_transferState.srcPointer) {
-        // Transfer the mip data
-        _transferState.populatePage(buffer);
-        if (GL_TEXTURE_2D == _target) {
-            glTextureSubImage2D(_id, _transferState.mipLevel,
-                offset.x, offset.y,
-                pageSize.x, pageSize.y,
-                _transferState.texelFormat.format, _transferState.texelFormat.type, &buffer[0]);
-        } else if (GL_TEXTURE_CUBE_MAP == _target) {
-            auto target = CUBE_FACE_LAYOUT[_transferState.face];
-            // DSA ARB does not work on AMD, so use EXT
-            // glTextureSubImage3D(_id, mipLevel, 0, 0, face, size.x, size.y, 1, texelFormat.format, texelFormat.type, mip->readData());
-            glTextureSubImage2DEXT(_id, target, _transferState.mipLevel,
-                offset.x, offset.y,
-                pageSize.x, pageSize.y,
-                _transferState.texelFormat.format, _transferState.texelFormat.type, &buffer[0]);
-        }
-    }
-
-    serverWait();
-    auto currentMip = _transferState.mipLevel;
-    auto result = _transferState.increment();
-    if (_sparseInfo.sparse && _transferState.mipLevel != currentMip && currentMip <= _sparseInfo.maxSparseLevel) {
-        auto mipDimensions = _gpuObject.evalMipDimensions(currentMip);
-        auto mipExpectedPages = _sparseInfo.getPageCount(mipDimensions);
-        auto newPages = _allocatedPages - _lastMipAllocatedPages;
-        if (newPages != mipExpectedPages) {
-            qCWarning(gpugl45logging) << "Unexpected page allocation size... " << newPages << " " << mipExpectedPages;
-        }
-        _lastMipAllocatedPages = _allocatedPages;
-    }
-    return result;
-#endif
 }
 
 void GL45Texture::finishTransfer() {
@@ -545,8 +406,8 @@ void GL45Texture::stripToMip(uint16_t newMinMip) {
             });
 
             auto deallocatedPages = _sparseInfo.getPageCount(mipDimensions) * maxFace;
-            assert(deallocatedPages < _allocatedPages);
-            _allocatedPages -= deallocatedPages;
+            assert(deallocatedPages < _sparseInfo.allocatedPages);
+            _sparseInfo.allocatedPages -= deallocatedPages;
         }
         _minMip = newMinMip;
     } else {

From 08bba5f45f221ea9d0ec3cce11a8d8526abfd08b Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Thu, 19 Jan 2017 17:31:29 -0800
Subject: [PATCH 02/17] add and remove some profile data points

---
 interface/src/avatar/Avatar.cpp      | 44 ++++++++++++++--------------
 libraries/animation/src/Rig.cpp      |  1 +
 libraries/render-utils/src/Model.cpp |  2 --
 3 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 6061812d2a..a3eaeab46a 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -308,6 +308,7 @@ void Avatar::setShouldDie() {
 }
 
 void Avatar::simulate(float deltaTime) {
+    PROFILE_RANGE(simulation, "simulate");
     PerformanceTimer perfTimer("simulate");
 
     if (!isDead() && !_motionState) {
@@ -317,8 +318,8 @@ void Avatar::simulate(float deltaTime) {
 
     bool avatarInView = false;
     { // update the shouldAnimate flag to match whether or not we will render the avatar.
-        PerformanceTimer perfTimer("cull");
         {
+            PROFILE_RANGE(simulation, "cull");
             // simple frustum check
             PerformanceTimer perfTimer("inView");
             ViewFrustum viewFrustum;
@@ -326,7 +327,7 @@ void Avatar::simulate(float deltaTime) {
             avatarInView = viewFrustum.sphereIntersectsFrustum(getPosition(), getBoundingRadius())
                 || viewFrustum.boxIntersectsFrustum(_skeletonModel->getRenderableMeshBound());
         }
-        PerformanceTimer lodPerfTimer("LOD");
+        PROFILE_RANGE(simulation, "LOD");
         if (avatarInView) {
             const float MINIMUM_VISIBILITY_FOR_ON = 0.4f;
             const float MAXIMUM_VISIBILITY_FOR_OFF = 0.6f;
@@ -346,19 +347,17 @@ void Avatar::simulate(float deltaTime) {
         }
     }
 
-    uint64_t start = usecTimestampNow();
-    // CRUFT? _shouldSkipRender is never set 'true'
-    if (_shouldAnimate && avatarInView && !_shouldSkipRender) {
-        {
-            PerformanceTimer perfTimer("skeleton");
+    {
+        PROFILE_RANGE(simulation, "updateJoints");
+        uint64_t start = usecTimestampNow();
+        // CRUFT? _shouldSkipRender is never set 'true'
+        if (_shouldAnimate && avatarInView && !_shouldSkipRender) {
             _skeletonModel->getRig()->copyJointsFromJointData(_jointData);
             _skeletonModel->simulate(deltaTime, _hasNewJointRotations || _hasNewJointTranslations);
             locationChanged(); // joints changed, so if there are any children, update them.
             _hasNewJointRotations = false;
             _hasNewJointTranslations = false;
-        }
-        {
-            PerformanceTimer perfTimer("head");
+
             glm::vec3 headPosition = getPosition();
             if (!_skeletonModel->getHeadPosition(headPosition)) {
                 headPosition = getPosition();
@@ -367,15 +366,14 @@ void Avatar::simulate(float deltaTime) {
             head->setPosition(headPosition);
             head->setScale(getUniformScale());
             head->simulate(deltaTime, false, !_shouldAnimate);
+        } else {
+            // a non-full update is still required so that the position, rotation, scale and bounds of the skeletonModel are updated.
+            getHead()->setPosition(getPosition());
+            _skeletonModel->simulate(deltaTime, false);
         }
-    } else {
-        // a non-full update is still required so that the position, rotation, scale and bounds of the skeletonModel are updated.
-        getHead()->setPosition(getPosition());
-        PerformanceTimer perfTimer("skeleton");
-        _skeletonModel->simulate(deltaTime, false);
+        timeProcessingJoints += usecTimestampNow() - start;
+        numJointsProcessed += _jointData.size();
     }
-    timeProcessingJoints += usecTimestampNow() - start;
-    numJointsProcessed += _jointData.size();
 
     // update animation for display name fade in/out
     if ( _displayNameTargetAlpha != _displayNameAlpha) {
@@ -394,11 +392,13 @@ void Avatar::simulate(float deltaTime) {
         _displayNameAlpha = abs(_displayNameAlpha - _displayNameTargetAlpha) < 0.01f ? _displayNameTargetAlpha : _displayNameAlpha;
     }
 
-    measureMotionDerivatives(deltaTime);
-
-    simulateAttachments(deltaTime);
-    updatePalms();
-    updateAvatarEntities();
+    {
+        PROFILE_RANGE(simulation, "misc");
+        measureMotionDerivatives(deltaTime);
+        simulateAttachments(deltaTime);
+        updatePalms();
+        updateAvatarEntities();
+    }
 }
 
 bool Avatar::isLookingAtMe(AvatarSharedPointer avatar) const {
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index fdeeb01739..ac16b16c1d 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -1269,6 +1269,7 @@ void Rig::copyJointsIntoJointData(QVector<JointData>& jointDataVec) const {
 
 void Rig::copyJointsFromJointData(const QVector<JointData>& jointDataVec) {
     PerformanceTimer perfTimer("copyJoints");
+    PROFILE_RANGE(simulation_animation_detail, "copyJoints");
     if (_animSkeleton && jointDataVec.size() == (int)_internalPoseSet._relativePoses.size()) {
         // make a vector of rotations in absolute-geometry-frame
         const AnimPoseVec& absoluteDefaultPoses = _animSkeleton->getAbsoluteDefaultPoses();
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index b79e69a9b7..d3fddc96d9 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -272,8 +272,6 @@ void Model::reset() {
 }
 
 bool Model::updateGeometry() {
-    PROFILE_RANGE(render_detail, __FUNCTION__);
-    PerformanceTimer perfTimer("Model::updateGeometry");
     bool needFullUpdate = false;
 
     if (!isLoaded()) {

From 88bf12616833f8be17b121a0af20126b81c488d4 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Fri, 20 Jan 2017 14:22:13 -0800
Subject: [PATCH 03/17] remove old avatar culling and LOD logic

---
 interface/src/avatar/Avatar.cpp        | 50 ++++++--------------------
 interface/src/avatar/Avatar.h          |  6 +---
 interface/src/avatar/AvatarManager.cpp |  6 ++--
 libraries/avatars/src/AvatarData.cpp   |  9 +++--
 libraries/avatars/src/AvatarData.h     |  3 +-
 5 files changed, 21 insertions(+), 53 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index a3eaeab46a..73c8a7553b 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -307,7 +307,7 @@ void Avatar::setShouldDie() {
     _owningAvatarMixer.clear();
 }
 
-void Avatar::simulate(float deltaTime) {
+void Avatar::simulate(float deltaTime, bool inView) {
     PROFILE_RANGE(simulation, "simulate");
     PerformanceTimer perfTimer("simulate");
 
@@ -316,47 +316,18 @@ void Avatar::simulate(float deltaTime) {
     }
     animateScaleChanges(deltaTime);
 
-    bool avatarInView = false;
-    { // update the shouldAnimate flag to match whether or not we will render the avatar.
-        {
-            PROFILE_RANGE(simulation, "cull");
-            // simple frustum check
-            PerformanceTimer perfTimer("inView");
-            ViewFrustum viewFrustum;
-            qApp->copyDisplayViewFrustum(viewFrustum);
-            avatarInView = viewFrustum.sphereIntersectsFrustum(getPosition(), getBoundingRadius())
-                || viewFrustum.boxIntersectsFrustum(_skeletonModel->getRenderableMeshBound());
-        }
-        PROFILE_RANGE(simulation, "LOD");
-        if (avatarInView) {
-            const float MINIMUM_VISIBILITY_FOR_ON = 0.4f;
-            const float MAXIMUM_VISIBILITY_FOR_OFF = 0.6f;
-            ViewFrustum viewFrustum;
-            qApp->copyViewFrustum(viewFrustum);
-            float visibility = calculateRenderAccuracy(viewFrustum.getPosition(),
-                getBounds(), DependencyManager::get<LODManager>()->getOctreeSizeScale());
-            if (!_shouldAnimate) {
-                if (visibility > MINIMUM_VISIBILITY_FOR_ON) {
-                    _shouldAnimate = true;
-                    qCDebug(interfaceapp) << "Restoring" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for visibility" << visibility;
-                }
-            } else if (visibility < MAXIMUM_VISIBILITY_FOR_OFF) {
-                _shouldAnimate = false;
-                qCDebug(interfaceapp) << "Optimizing" << (isMyAvatar() ? "myself" : getSessionUUID()) << "for visibility" << visibility;
-            }
-        }
-    }
-
     {
         PROFILE_RANGE(simulation, "updateJoints");
         uint64_t start = usecTimestampNow();
-        // CRUFT? _shouldSkipRender is never set 'true'
-        if (_shouldAnimate && avatarInView && !_shouldSkipRender) {
+        if (inView) {
+            // adebug BOOKMARK: can avoid copying duplicate joint data
+            // - can avoid some work when transform not changed (see SkeletonModel::simulate() and Model::setTranslation())
+            // - can maybe use _hasNewFoo instead of AvatarData::_jointDataVersion
+            // - can maybe avoid stuff if blendShapes haven't changed
             _skeletonModel->getRig()->copyJointsFromJointData(_jointData);
-            _skeletonModel->simulate(deltaTime, _hasNewJointRotations || _hasNewJointTranslations);
+            _skeletonModel->simulate(deltaTime, _hasNewJointData);
             locationChanged(); // joints changed, so if there are any children, update them.
-            _hasNewJointRotations = false;
-            _hasNewJointTranslations = false;
+            _hasNewJointData = false;
 
             glm::vec3 headPosition = getPosition();
             if (!_skeletonModel->getHeadPosition(headPosition)) {
@@ -365,7 +336,8 @@ void Avatar::simulate(float deltaTime) {
             Head* head = getHead();
             head->setPosition(headPosition);
             head->setScale(getUniformScale());
-            head->simulate(deltaTime, false, !_shouldAnimate);
+            const bool useBillboard = false; // HACK
+            head->simulate(deltaTime, false, useBillboard);
         } else {
             // a non-full update is still required so that the position, rotation, scale and bounds of the skeletonModel are updated.
             getHead()->setPosition(getPosition());
@@ -1106,7 +1078,7 @@ int Avatar::parseDataFromBuffer(const QByteArray& buffer) {
     if (_moving && _motionState) {
         _motionState->addDirtyFlags(Simulation::DIRTY_POSITION);
     }
-    if (_moving || _hasNewJointRotations || _hasNewJointTranslations) {
+    if (_moving || _hasNewJointData) {
         locationChanged();
     }
 
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index d370402865..75af330452 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -68,7 +68,7 @@ public:
 
     void init();
     void updateAvatarEntities();
-    void simulate(float deltaTime);
+    void simulate(float deltaTime, bool inView);
     virtual void simulateAttachments(float deltaTime);
 
     virtual void render(RenderArgs* renderArgs, const glm::vec3& cameraPosition);
@@ -141,8 +141,6 @@ public:
 
     Q_INVOKABLE glm::vec3 getAcceleration() const { return _acceleration; }
 
-    Q_INVOKABLE bool getShouldRender() const { return !_shouldSkipRender; }
-
     /// Scales a world space position vector relative to the avatar position and scale
     /// \param vector position to be scaled. Will store the result
     void scaleVectorRelativeToPosition(glm::vec3 &positionToScale) const;
@@ -265,8 +263,6 @@ private:
     int _rightPointerGeometryID { 0 };
     int _nameRectGeometryID { 0 };
     bool _initialized;
-    bool _shouldAnimate { true };
-    bool _shouldSkipRender { false };
     bool _isLookAtTarget { false };
     bool _inScene { false };
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index b0dc9922ff..4ba3cbdc1a 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -165,7 +165,8 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
             ++avatarIterator;
         } else {
             avatar->ensureInScene(avatar);
-            avatar->simulate(deltaTime);
+            const bool inView = true; // HACK
+            avatar->simulate(deltaTime, inView);
             ++avatarIterator;
 
             avatar->updateRenderItem(pendingChanges);
@@ -210,7 +211,8 @@ void AvatarManager::simulateAvatarFades(float deltaTime) {
                 ++fadingIterator;
             }
         } else {
-            avatar->simulate(deltaTime);
+            const bool inView = true; // HACK
+            avatar->simulate(deltaTime, inView);
             ++fadingIterator;
         }
     }
diff --git a/libraries/avatars/src/AvatarData.cpp b/libraries/avatars/src/AvatarData.cpp
index 1fb68fce14..1aacb00c04 100644
--- a/libraries/avatars/src/AvatarData.cpp
+++ b/libraries/avatars/src/AvatarData.cpp
@@ -120,8 +120,7 @@ AvatarData::AvatarData() :
     _handState(0),
     _keyState(NO_KEY_DOWN),
     _forceFaceTrackerConnected(false),
-    _hasNewJointRotations(true),
-    _hasNewJointTranslations(true),
+    _hasNewJointData(true),
     _headData(NULL),
     _displayNameTargetAlpha(1.0f),
     _displayNameAlpha(1.0f),
@@ -553,7 +552,7 @@ int AvatarData::parseDataFromBuffer(const QByteArray& buffer) {
     glm::vec3 newEulerAngles(pitch, yaw, roll);
     glm::quat newOrientation = glm::quat(glm::radians(newEulerAngles));
     if (currentOrientation != newOrientation) {
-        _hasNewJointRotations = true;
+        _hasNewJointData = true;
         setLocalOrientation(newOrientation);
     }
 
@@ -680,7 +679,7 @@ int AvatarData::parseDataFromBuffer(const QByteArray& buffer) {
         JointData& data = _jointData[i];
         if (validRotations[i]) {
             sourceBuffer += unpackOrientationQuatFromSixBytes(sourceBuffer, data.rotation);
-            _hasNewJointRotations = true;
+            _hasNewJointData = true;
             data.rotationSet = true;
         }
     }
@@ -715,7 +714,7 @@ int AvatarData::parseDataFromBuffer(const QByteArray& buffer) {
         JointData& data = _jointData[i];
         if (validTranslations[i]) {
             sourceBuffer += unpackFloatVec3FromSignedTwoByteFixed(sourceBuffer, data.translation, TRANSLATION_COMPRESSION_RADIX);
-            _hasNewJointTranslations = true;
+            _hasNewJointData = true;
             data.translationSet = true;
         }
     }
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index db06d52092..a3c9e537ca 100644
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -427,8 +427,7 @@ protected:
     KeyState _keyState;
 
     bool _forceFaceTrackerConnected;
-    bool _hasNewJointRotations; // set in AvatarData, cleared in Avatar
-    bool _hasNewJointTranslations; // set in AvatarData, cleared in Avatar
+    bool _hasNewJointData; // set in AvatarData, cleared in Avatar
 
     HeadData* _headData;
 

From d8a10320d1377652d8e7281a6c93047be6558843 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 14:04:24 -0800
Subject: [PATCH 04/17] fix warning about implicit cast

---
 libraries/shared/src/ViewFrustum.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libraries/shared/src/ViewFrustum.cpp b/libraries/shared/src/ViewFrustum.cpp
index b4ed462639..a0b7d17e46 100644
--- a/libraries/shared/src/ViewFrustum.cpp
+++ b/libraries/shared/src/ViewFrustum.cpp
@@ -729,7 +729,7 @@ void ViewFrustum::evalProjectionMatrix(glm::mat4& proj) const {
 glm::mat4 ViewFrustum::evalProjectionMatrixRange(float rangeNear, float rangeFar) const {
 
     // make sure range near far make sense
-    assert(rangeNear > 0.0);
+    assert(rangeNear > 0.0f);
     assert(rangeFar > rangeNear);
 
     // recreate a projection matrix for only a range of depth of this frustum.
@@ -738,7 +738,7 @@ glm::mat4 ViewFrustum::evalProjectionMatrixRange(float rangeNear, float rangeFar
     glm::mat4 rangeProj = _projection;
     
     float A = -(rangeFar + rangeNear) / (rangeFar - rangeNear);
-    float B = -2 * rangeFar*rangeNear / ((rangeFar - rangeNear));
+    float B = -2.0f * rangeFar*rangeNear / ((rangeFar - rangeNear));
 
     rangeProj[2][2] = A;
     rangeProj[3][2] = B;

From 09707217ec40c64470583c2e58adc397629d583a Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 14:04:33 -0800
Subject: [PATCH 05/17] remove Model::simulateInternal()

---
 libraries/render-utils/src/Model.cpp | 10 +++-------
 libraries/render-utils/src/Model.h   |  1 -
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index d3fddc96d9..1e83a874dc 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -1126,7 +1126,9 @@ void Model::simulate(float deltaTime, bool fullUpdate) {
         if (_snapModelToRegistrationPoint && !_snappedToRegistrationPoint) {
             snapToRegistrationPoint();
         }
-        simulateInternal(deltaTime);
+        // update the world space transforms for all joints
+        glm::mat4 parentTransform = glm::scale(_scale) * glm::translate(_offset);
+        updateRig(deltaTime, parentTransform);
     }
 }
 
@@ -1136,12 +1138,6 @@ void Model::updateRig(float deltaTime, glm::mat4 parentTransform) {
     _rig->updateAnimations(deltaTime, parentTransform);
 }
 
-void Model::simulateInternal(float deltaTime) {
-    // update the world space transforms for all joints
-    glm::mat4 parentTransform = glm::scale(_scale) * glm::translate(_offset);
-    updateRig(deltaTime, parentTransform);
-}
-
 // virtual
 void Model::updateClusterMatrices() {
     PerformanceTimer perfTimer("Model::updateClusterMatrices");
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index 246d67180e..3f673b0250 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -312,7 +312,6 @@ protected:
     void scaleToFit();
     void snapToRegistrationPoint();
 
-    void simulateInternal(float deltaTime);
     virtual void updateRig(float deltaTime, glm::mat4 parentTransform);
 
     /// Restores the indexed joint to its default position.

From e3634239921cc09c20096195203cd5d7114e8929 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 14:05:25 -0800
Subject: [PATCH 06/17] compute priority of avatar and sort before update

---
 interface/src/avatar/Avatar.cpp        |  5 +-
 interface/src/avatar/Avatar.h          |  4 ++
 interface/src/avatar/AvatarManager.cpp | 87 +++++++++++++++++++-------
 3 files changed, 69 insertions(+), 27 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 73c8a7553b..260373bf50 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -127,6 +127,7 @@ Avatar::Avatar(RigPointer rig) :
     _nameRectGeometryID = geometryCache->allocateID();
     _leftPointerGeometryID = geometryCache->allocateID();
     _rightPointerGeometryID = geometryCache->allocateID();
+    _lastRenderUpdateTime = usecTimestampNow();
 }
 
 Avatar::~Avatar() {
@@ -320,10 +321,6 @@ void Avatar::simulate(float deltaTime, bool inView) {
         PROFILE_RANGE(simulation, "updateJoints");
         uint64_t start = usecTimestampNow();
         if (inView) {
-            // adebug BOOKMARK: can avoid copying duplicate joint data
-            // - can avoid some work when transform not changed (see SkeletonModel::simulate() and Model::setTranslation())
-            // - can maybe use _hasNewFoo instead of AvatarData::_jointDataVersion
-            // - can maybe avoid stuff if blendShapes haven't changed
             _skeletonModel->getRig()->copyJointsFromJointData(_jointData);
             _skeletonModel->simulate(deltaTime, _hasNewJointData);
             locationChanged(); // joints changed, so if there are any children, update them.
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index 75af330452..3276eaff47 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -177,6 +177,9 @@ public:
     glm::vec3 getUncachedRightPalmPosition() const;
     glm::quat getUncachedRightPalmRotation() const;
 
+    uint64_t getLastRenderUpdateTime() const { return _lastRenderUpdateTime; }
+    void setLastRenderUpdateTime(uint64_t time) { _lastRenderUpdateTime = time; }
+
     Q_INVOKABLE void setShouldDie();
 
 public slots:
@@ -259,6 +262,7 @@ protected:
     void ensureInScene(AvatarSharedPointer self);
 
 private:
+    uint64_t _lastRenderUpdateTime { 0 };
     int _leftPointerGeometryID { 0 };
     int _rightPointerGeometryID { 0 };
     int _nameRectGeometryID { 0 };
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 4ba3cbdc1a..e3d3164b68 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -132,53 +132,94 @@ void AvatarManager::updateMyAvatar(float deltaTime) {
 
 Q_LOGGING_CATEGORY(trace_simulation_avatar, "trace.simulation.avatar");
 
+class AvatarPriority {
+public:
+    AvatarPriority(AvatarSharedPointer a, float p) : avatar(a), priority(p) {}
+    AvatarSharedPointer avatar;
+    float priority;
+    // NOTE: we invert the less-than operator to sort high priorities to front
+    bool operator<(const AvatarPriority& other) const { return priority > other.priority; }
+};
+
 void AvatarManager::updateOtherAvatars(float deltaTime) {
     // lock the hash for read to check the size
     QReadLocker lock(&_hashLock);
-
     if (_avatarHash.size() < 2 && _avatarFades.isEmpty()) {
         return;
     }
-
     lock.unlock();
 
     bool showWarnings = Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings);
     PerformanceWarning warn(showWarnings, "Application::updateAvatars()");
 
     PerformanceTimer perfTimer("otherAvatars");
-    render::PendingChanges pendingChanges;
 
-    // simulate avatars
-    auto hashCopy = getHashCopy();
+    auto avatarMap = getHashCopy();
+    QList<AvatarSharedPointer> avatarList = avatarMap.values();
+    uint64_t now = usecTimestampNow();
+    ViewFrustum cameraView;
+    qApp->copyDisplayViewFrustum(cameraView);
+    glm::vec3 frustumCenter = cameraView.getPosition();
 
-    uint64_t start = usecTimestampNow();
-    AvatarHash::iterator avatarIterator = hashCopy.begin();
-    while (avatarIterator != hashCopy.end()) {
-        auto avatar = std::static_pointer_cast<Avatar>(avatarIterator.value());
+    const float OUT_OF_VIEW_PENALTY = -10.0;
 
+    std::priority_queue<AvatarPriority> sortedAvatars;
+    for (int32_t i = 0; i < avatarList.size(); ++i) {
+        const auto& avatar = std::static_pointer_cast<Avatar>(avatarList.at(i));
         if (avatar == _myAvatar || !avatar->isInitialized()) {
             // DO NOT update _myAvatar!  Its update has already been done earlier in the main loop.
             // DO NOT update or fade out uninitialized Avatars
-            ++avatarIterator;
-        } else if (avatar->shouldDie()) {
-            removeAvatar(avatarIterator.key());
-            ++avatarIterator;
-        } else {
-            avatar->ensureInScene(avatar);
-            const bool inView = true; // HACK
-            avatar->simulate(deltaTime, inView);
-            ++avatarIterator;
-
-            avatar->updateRenderItem(pendingChanges);
+            continue;
         }
+        if (avatar->shouldDie()) {
+            removeAvatar(avatar->getID());
+            continue;
+        }
+
+        // priority = weighted linear combination of:
+        //   (a) apparentSize
+        //   (b) proximity to center of view, and
+        //   (c) time since last update
+        glm::vec3 avatarPosition = avatar->getPosition();
+        glm::vec3 offset = avatarPosition - frustumCenter;
+        float distance = glm::length(offset) + 0.001f; // add 1mm to avoid divide by zero
+        float radius = avatar->getBoundingRadius();
+        const glm::vec3& forward = cameraView.getDirection();
+        float apparentSize = radius / distance;
+        float cosineAngle = glm::length(offset - glm::dot(offset, forward) * forward) / distance;
+        float age = (float)(now - avatar->getLastRenderUpdateTime()) / (float)(USECS_PER_SECOND);
+        float priority = 2.0f * apparentSize + 0.25f * cosineAngle + age;
+
+        // decrement priority of avatars outside keyhole
+        if (distance > cameraView.getCenterRadius()) {
+            if (!cameraView.sphereIntersectsFrustum(avatarPosition, radius)) {
+                priority += OUT_OF_VIEW_PENALTY;
+            }
+        }
+        sortedAvatars.push(AvatarPriority(avatar, priority));
+    }
+
+    render::PendingChanges pendingChanges;
+    const uint64_t AVATAR_RENDER_UPDATE_TIME_BUDGET = 2 * USECS_PER_MSEC;
+    uint64_t expiry = now + AVATAR_RENDER_UPDATE_TIME_BUDGET;
+    while (!sortedAvatars.empty()) {
+        const AvatarPriority& sortData = sortedAvatars.top();
+        const auto& avatar = std::static_pointer_cast<Avatar>(sortData.avatar);
+        avatar->ensureInScene(avatar);
+        const bool inView = sortData.priority > 0.5f * OUT_OF_VIEW_PENALTY;
+        avatar->simulate(deltaTime, inView);
+        if (expiry > usecTimestampNow()) {
+            avatar->updateRenderItem(pendingChanges);
+            avatar->setLastRenderUpdateTime(now);
+        }
+        sortedAvatars.pop();
     }
     qApp->getMain3DScene()->enqueuePendingChanges(pendingChanges);
 
-    // simulate avatar fades
     simulateAvatarFades(deltaTime);
 
-    PROFILE_COUNTER(simulation_avatar, "NumAvatarsPerSec",
-            { { "NumAvatarsPerSec", (float)(size() * USECS_PER_SECOND) / (float)(usecTimestampNow() - start) } });
+    //PROFILE_COUNTER(simulation_avatar, "NumAvatarsPerSec",
+    //        { { "NumAvatarsPerSec", (float)((size() - sortedAvatars.size()) * USECS_PER_SECOND) / (float)(usecTimestampNow() - now) } });
     PROFILE_COUNTER(simulation_avatar, "NumJointsPerSec", { { "NumJointsPerSec", Avatar::getNumJointsProcessedPerSecond() } });
 }
 

From e65d9309b3592e2b97b3861bf1cf6511985b2c73 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 14:56:10 -0800
Subject: [PATCH 07/17] remove cruft: Avatar::setShouldDie()

---
 interface/src/avatar/Avatar.cpp    | 6 +++---
 interface/src/avatar/Avatar.h      | 2 +-
 libraries/avatars/src/AvatarData.h | 4 ----
 3 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 260373bf50..c5c5dacfc6 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -303,9 +303,9 @@ void Avatar::updateAvatarEntities() {
     }
 }
 
-void Avatar::setShouldDie() {
-    // This will cause the avatar to be shrunk away and removed (the actual Avatar gets removed), but then it comes back.
-    _owningAvatarMixer.clear();
+bool Avatar::shouldDie() const {
+    const qint64 AVATAR_SILENCE_THRESHOLD_USECS = 5 * USECS_PER_SECOND;
+    return _owningAvatarMixer.isNull() || getUsecsSinceLastUpdate() > AVATAR_SILENCE_THRESHOLD_USECS;
 }
 
 void Avatar::simulate(float deltaTime, bool inView) {
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index 3276eaff47..d6f588c47e 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -180,7 +180,7 @@ public:
     uint64_t getLastRenderUpdateTime() const { return _lastRenderUpdateTime; }
     void setLastRenderUpdateTime(uint64_t time) { _lastRenderUpdateTime = time; }
 
-    Q_INVOKABLE void setShouldDie();
+    bool shouldDie() const;
 
 public slots:
 
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index a3c9e537ca..093530235b 100644
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -81,8 +81,6 @@ const quint32 AVATAR_MOTION_DEFAULTS =
 const quint32 AVATAR_MOTION_SCRIPTABLE_BITS =
         AVATAR_MOTION_SCRIPTED_MOTOR_ENABLED;
 
-const qint64 AVATAR_SILENCE_THRESHOLD_USECS = 5 * USECS_PER_SECOND;
-
 // Bitset of state flags - we store the key state, hand state, Faceshift, eye tracking, and existence of
 // referential data in this bit set. The hand state is an octal, but is split into two sections to maintain
 // backward compatibility. The bits are ordered as such (0-7 left to right).
@@ -371,8 +369,6 @@ public:
 
     const glm::vec3& getTargetVelocity() const { return _targetVelocity; }
 
-    bool shouldDie() const { return _owningAvatarMixer.isNull() || getUsecsSinceLastUpdate() > AVATAR_SILENCE_THRESHOLD_USECS; }
-
     void clearRecordingBasis();
     TransformPointer getRecordingBasis() const;
     void setRecordingBasis(TransformPointer recordingBasis = TransformPointer());

From b8afc87ad976513f6bfa6025887081de523237d4 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 16:12:36 -0800
Subject: [PATCH 08/17] remove cruft

---
 interface/src/ui/PreferencesDialog.cpp | 2 +-
 libraries/avatars/src/AvatarData.cpp   | 5 -----
 libraries/avatars/src/AvatarData.h     | 3 +--
 3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/interface/src/ui/PreferencesDialog.cpp b/interface/src/ui/PreferencesDialog.cpp
index a4cb62cc13..828e2e772d 100644
--- a/interface/src/ui/PreferencesDialog.cpp
+++ b/interface/src/ui/PreferencesDialog.cpp
@@ -157,7 +157,7 @@ void setupPreferences() {
     }
     {
         auto getter = [=]()->float { return myAvatar->getUniformScale(); };
-        auto setter = [=](float value) { myAvatar->setTargetScaleVerbose(value); }; // The hell?
+        auto setter = [=](float value) { myAvatar->setTargetScale(value); };
         auto preference = new SpinnerPreference(AVATAR_TUNING, "Avatar scale (default is 1.0)", getter, setter);
         preference->setMin(0.01f);
         preference->setMax(99.9f);
diff --git a/libraries/avatars/src/AvatarData.cpp b/libraries/avatars/src/AvatarData.cpp
index 1aacb00c04..701fae1b2b 100644
--- a/libraries/avatars/src/AvatarData.cpp
+++ b/libraries/avatars/src/AvatarData.cpp
@@ -179,11 +179,6 @@ void AvatarData::setTargetScale(float targetScale) {
     _targetScale = glm::clamp(targetScale, MIN_AVATAR_SCALE, MAX_AVATAR_SCALE);
 }
 
-void AvatarData::setTargetScaleVerbose(float targetScale) {
-    setTargetScale(targetScale);
-    qCDebug(avatars) << "Changed scale to " << _targetScale;
-}
-
 glm::vec3 AvatarData::getHandPosition() const {
     return getOrientation() * _handPosition + getPosition();
 }
diff --git a/libraries/avatars/src/AvatarData.h b/libraries/avatars/src/AvatarData.h
index 093530235b..f07d9a2ba6 100644
--- a/libraries/avatars/src/AvatarData.h
+++ b/libraries/avatars/src/AvatarData.h
@@ -262,8 +262,7 @@ public:
 
     //  Scale
     float getTargetScale() const;
-    void setTargetScale(float targetScale);
-    void setTargetScaleVerbose(float targetScale);
+    virtual void setTargetScale(float targetScale);
 
     float getDomainLimitedScale() const { return glm::clamp(_targetScale, _domainMinimumScale, _domainMaximumScale); }
     void setDomainMinimumScale(float domainMinimumScale)

From 69a7b1ef76c4892f7ee28b4080c132f392d074b1 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 16:12:47 -0800
Subject: [PATCH 09/17] move some stuff out of Avatar::simulate()

call it explicity in AvatarManager::updateOtherAvatars()
---
 interface/src/avatar/Avatar.cpp        | 28 +++++++++++++++-----------
 interface/src/avatar/Avatar.h          |  5 +++--
 interface/src/avatar/AvatarManager.cpp | 22 ++++++++++++++++++++
 interface/src/avatar/AvatarManager.h   |  2 +-
 4 files changed, 42 insertions(+), 15 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index c5c5dacfc6..208d265dcd 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -188,25 +188,35 @@ AABox Avatar::getBounds() const {
 }
 
 void Avatar::animateScaleChanges(float deltaTime) {
-    float currentScale = getUniformScale();
-    auto desiredScale = getDomainLimitedScale();
-    if (currentScale != desiredScale) {
+    if (_isAnimatingScale) {
+        float currentScale = getUniformScale();
+        float desiredScale = getDomainLimitedScale();
+
         // use exponential decay toward the domain limit clamped scale
         const float SCALE_ANIMATION_TIMESCALE = 0.5f;
         float blendFactor = glm::clamp(deltaTime / SCALE_ANIMATION_TIMESCALE, 0.0f, 1.0f);
         float animatedScale = (1.0f - blendFactor) * currentScale + blendFactor * desiredScale;
 
         // snap to the end when we get close enough
-        const float MIN_RELATIVE_SCALE_ERROR = 0.03f;
-        if (fabsf(desiredScale - currentScale) / desiredScale < MIN_RELATIVE_SCALE_ERROR) {
+        const float MIN_RELATIVE_ERROR = 0.03f;
+        float relativeError = fabsf(desiredScale - currentScale) / desiredScale;
+        if (relativeError < MIN_RELATIVE_ERROR) {
             animatedScale = desiredScale;
+            _isAnimatingScale = false;
         }
-
         setScale(glm::vec3(animatedScale)); // avatar scale is uniform
+
+        // TODO: rebuilding the shape constantly is somehwat expensive.
+        // We should only rebuild after significant change.
         rebuildCollisionShape();
     }
 }
 
+void Avatar::setTargetScale(float targetScale) {
+    AvatarData::setTargetScale(targetScale);
+    _isAnimatingScale = true;
+}
+
 void Avatar::updateAvatarEntities() {
     PerformanceTimer perfTimer("attachments");
     // - if queueEditEntityMessage sees clientOnly flag it does _myAvatar->updateAvatarEntity()
@@ -311,12 +321,6 @@ bool Avatar::shouldDie() const {
 void Avatar::simulate(float deltaTime, bool inView) {
     PROFILE_RANGE(simulation, "simulate");
     PerformanceTimer perfTimer("simulate");
-
-    if (!isDead() && !_motionState) {
-        DependencyManager::get<AvatarManager>()->addAvatarToSimulation(this);
-    }
-    animateScaleChanges(deltaTime);
-
     {
         PROFILE_RANGE(simulation, "updateJoints");
         uint64_t start = usecTimestampNow();
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index d6f588c47e..a6c5bbf16f 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -181,6 +181,8 @@ public:
     void setLastRenderUpdateTime(uint64_t time) { _lastRenderUpdateTime = time; }
 
     bool shouldDie() const;
+    void animateScaleChanges(float deltaTime);
+    void setTargetScale(float targetScale) override;
 
 public slots:
 
@@ -231,8 +233,6 @@ protected:
     // protected methods...
     bool isLookingAtMe(AvatarSharedPointer avatar) const;
 
-    virtual void animateScaleChanges(float deltaTime);
-
     glm::vec3 getBodyRightDirection() const { return getOrientation() * IDENTITY_RIGHT; }
     glm::vec3 getBodyUpDirection() const { return getOrientation() * IDENTITY_UP; }
     glm::vec3 getBodyFrontDirection() const { return getOrientation() * IDENTITY_FRONT; }
@@ -269,6 +269,7 @@ private:
     bool _initialized;
     bool _isLookAtTarget { false };
     bool _inScene { false };
+    bool _isAnimatingScale { false };
 
     float getBoundingRadius() const;
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index e3d3164b68..fa2ee2190c 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -175,6 +175,9 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
             removeAvatar(avatar->getID());
             continue;
         }
+        if (avatar->isDead()) {
+            continue;
+        }
 
         // priority = weighted linear combination of:
         //   (a) apparentSize
@@ -205,7 +208,24 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     while (!sortedAvatars.empty()) {
         const AvatarPriority& sortData = sortedAvatars.top();
         const auto& avatar = std::static_pointer_cast<Avatar>(sortData.avatar);
+
+        // for ALL avatars...
         avatar->ensureInScene(avatar);
+        if (!avatar->getMotionState()) {
+            ShapeInfo shapeInfo;
+            avatar->computeShapeInfo(shapeInfo);
+            btCollisionShape* shape = const_cast<btCollisionShape*>(ObjectMotionState::getShapeManager()->getShape(shapeInfo));
+            if (shape) {
+                // don't add to the simulation now, instead put it on a list to be added later
+                AvatarMotionState* motionState = new AvatarMotionState(avatar.get(), shape);
+                avatar->setMotionState(motionState);
+                _motionStatesToAddToPhysics.insert(motionState);
+                _motionStatesThatMightUpdate.insert(motionState);
+            }
+        }
+        avatar->animateScaleChanges(deltaTime);
+
+        // for avatars in view...
         const bool inView = sortData.priority > 0.5f * OUT_OF_VIEW_PENALTY;
         avatar->simulate(deltaTime, inView);
         if (expiry > usecTimestampNow()) {
@@ -429,6 +449,7 @@ void AvatarManager::handleCollisionEvents(const CollisionEvents& collisionEvents
     }
 }
 
+/*
 void AvatarManager::addAvatarToSimulation(Avatar* avatar) {
     assert(!avatar->getMotionState());
 
@@ -443,6 +464,7 @@ void AvatarManager::addAvatarToSimulation(Avatar* avatar) {
         _motionStatesThatMightUpdate.insert(motionState);
     }
 }
+*/
 
 void AvatarManager::updateAvatarRenderStatus(bool shouldRenderAvatars) {
     if (DependencyManager::get<SceneScriptingInterface>()->shouldRenderAvatars()) {
diff --git a/interface/src/avatar/AvatarManager.h b/interface/src/avatar/AvatarManager.h
index a423e34f8f..efb01e071f 100644
--- a/interface/src/avatar/AvatarManager.h
+++ b/interface/src/avatar/AvatarManager.h
@@ -69,7 +69,7 @@ public:
     void handleOutgoingChanges(const VectorOfMotionStates& motionStates);
     void handleCollisionEvents(const CollisionEvents& collisionEvents);
 
-    void addAvatarToSimulation(Avatar* avatar);
+    //void addAvatarToSimulation(Avatar* avatar);
 
     Q_INVOKABLE RayToAvatarIntersectionResult findRayIntersection(const PickRay& ray,
                                                                   const QScriptValue& avatarIdsToInclude = QScriptValue(),

From 887707426eb7e383604ff1964a37bc37b8811da3 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 17:03:26 -0800
Subject: [PATCH 10/17] remove cruft: Head::getScalePivot()

---
 interface/src/avatar/Head.cpp | 4 ----
 interface/src/avatar/Head.h   | 2 --
 2 files changed, 6 deletions(-)

diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index 928f46facb..66beafcdd8 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -378,10 +378,6 @@ glm::quat Head::getEyeRotation(const glm::vec3& eyePosition) const {
     return rotationBetween(orientation * IDENTITY_FRONT, lookAtDelta + glm::length(lookAtDelta) * _saccade) * orientation;
 }
 
-glm::vec3 Head::getScalePivot() const {
-    return _position;
-}
-
 void Head::setFinalPitch(float finalPitch) {
     _deltaPitch = glm::clamp(finalPitch, MIN_HEAD_PITCH, MAX_HEAD_PITCH) - _basePitch;
 }
diff --git a/interface/src/avatar/Head.h b/interface/src/avatar/Head.h
index 29cd06865c..b1ea36df3d 100644
--- a/interface/src/avatar/Head.h
+++ b/interface/src/avatar/Head.h
@@ -70,8 +70,6 @@ public:
 
     bool getReturnToCenter() const { return _returnHeadToCenter; } // Do you want head to try to return to center (depends on interface detected)
     float getAverageLoudness() const { return _averageLoudness; }
-    /// \return the point about which scaling occurs.
-    glm::vec3 getScalePivot() const;
 
     void setDeltaPitch(float pitch) { _deltaPitch = pitch; }
     float getDeltaPitch() const { return _deltaPitch; }

From d3dcc2b41559e5c122fd7abb18f2857e94525fa6 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Mon, 23 Jan 2017 17:28:54 -0800
Subject: [PATCH 11/17] remove cruft: billboard option for Head::simulate()

---
 interface/src/avatar/Head.cpp | 6 +++---
 interface/src/avatar/Head.h   | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index 66beafcdd8..d7bf2b79bf 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -70,7 +70,7 @@ void Head::reset() {
     _baseYaw = _basePitch = _baseRoll = 0.0f;
 }
 
-void Head::simulate(float deltaTime, bool isMine, bool billboard) {
+void Head::simulate(float deltaTime, bool isMine) {
     //  Update audio trailing average for rendering facial animations
     const float AUDIO_AVERAGING_SECS = 0.05f;
     const float AUDIO_LONG_TERM_AVERAGING_SECS = 30.0f;
@@ -117,7 +117,7 @@ void Head::simulate(float deltaTime, bool isMine, bool billboard) {
         }
     }
    
-    if (!(_isFaceTrackerConnected || billboard)) {
+    if (!_isFaceTrackerConnected) {
 
         if (!_isEyeTrackerConnected) {
             // Update eye saccades
@@ -220,7 +220,7 @@ void Head::simulate(float deltaTime, bool isMine, bool billboard) {
     _leftEyePosition = _rightEyePosition = getPosition();
     _eyePosition = getPosition();
 
-    if (!billboard && _owningAvatar) {
+    if (_owningAvatar) {
         auto skeletonModel = static_cast<Avatar*>(_owningAvatar)->getSkeletonModel();
         if (skeletonModel) {
             skeletonModel->getEyePositions(_leftEyePosition, _rightEyePosition);
diff --git a/interface/src/avatar/Head.h b/interface/src/avatar/Head.h
index b1ea36df3d..3d25c79087 100644
--- a/interface/src/avatar/Head.h
+++ b/interface/src/avatar/Head.h
@@ -31,7 +31,7 @@ public:
 
     void init();
     void reset();
-    void simulate(float deltaTime, bool isMine, bool billboard = false);
+    void simulate(float deltaTime, bool isMine);
     void setScale(float scale);
     void setPosition(glm::vec3 position) { _position = position; }
     void setAverageLoudness(float averageLoudness) { _averageLoudness = averageLoudness; }

From ac180758ad87dab53efd4747c237f99f0fe58fba Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Tue, 24 Jan 2017 10:36:42 -0800
Subject: [PATCH 12/17] sort, optimize, and timebox process avatar updates

---
 interface/src/avatar/Avatar.cpp        |  15 ++--
 interface/src/avatar/AvatarManager.cpp | 112 ++++++++++++++-----------
 interface/src/avatar/SkeletonModel.cpp |  18 ++--
 3 files changed, 83 insertions(+), 62 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 208d265dcd..cdf9323ace 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -323,10 +323,13 @@ void Avatar::simulate(float deltaTime, bool inView) {
     PerformanceTimer perfTimer("simulate");
     {
         PROFILE_RANGE(simulation, "updateJoints");
-        uint64_t start = usecTimestampNow();
-        if (inView) {
+        if (inView && _hasNewJointData) {
+            uint64_t start = usecTimestampNow();
             _skeletonModel->getRig()->copyJointsFromJointData(_jointData);
-            _skeletonModel->simulate(deltaTime, _hasNewJointData);
+            _skeletonModel->simulate(deltaTime, true);
+            timeProcessingJoints += usecTimestampNow() - start;
+            numJointsProcessed += _jointData.size();
+
             locationChanged(); // joints changed, so if there are any children, update them.
             _hasNewJointData = false;
 
@@ -337,15 +340,11 @@ void Avatar::simulate(float deltaTime, bool inView) {
             Head* head = getHead();
             head->setPosition(headPosition);
             head->setScale(getUniformScale());
-            const bool useBillboard = false; // HACK
-            head->simulate(deltaTime, false, useBillboard);
+            head->simulate(deltaTime, false);
         } else {
             // a non-full update is still required so that the position, rotation, scale and bounds of the skeletonModel are updated.
-            getHead()->setPosition(getPosition());
             _skeletonModel->simulate(deltaTime, false);
         }
-        timeProcessingJoints += usecTimestampNow() - start;
-        numJointsProcessed += _jointData.size();
     }
 
     // update animation for display name fade in/out
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index fa2ee2190c..73f3fb0f38 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -149,14 +149,11 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     }
     lock.unlock();
 
-    bool showWarnings = Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings);
-    PerformanceWarning warn(showWarnings, "Application::updateAvatars()");
-
     PerformanceTimer perfTimer("otherAvatars");
+    uint64_t startTime = usecTimestampNow();
 
     auto avatarMap = getHashCopy();
     QList<AvatarSharedPointer> avatarList = avatarMap.values();
-    uint64_t now = usecTimestampNow();
     ViewFrustum cameraView;
     qApp->copyDisplayViewFrustum(cameraView);
     glm::vec3 frustumCenter = cameraView.getPosition();
@@ -164,47 +161,56 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     const float OUT_OF_VIEW_PENALTY = -10.0;
 
     std::priority_queue<AvatarPriority> sortedAvatars;
-    for (int32_t i = 0; i < avatarList.size(); ++i) {
-        const auto& avatar = std::static_pointer_cast<Avatar>(avatarList.at(i));
-        if (avatar == _myAvatar || !avatar->isInitialized()) {
-            // DO NOT update _myAvatar!  Its update has already been done earlier in the main loop.
-            // DO NOT update or fade out uninitialized Avatars
-            continue;
-        }
-        if (avatar->shouldDie()) {
-            removeAvatar(avatar->getID());
-            continue;
-        }
-        if (avatar->isDead()) {
-            continue;
-        }
-
-        // priority = weighted linear combination of:
-        //   (a) apparentSize
-        //   (b) proximity to center of view, and
-        //   (c) time since last update
-        glm::vec3 avatarPosition = avatar->getPosition();
-        glm::vec3 offset = avatarPosition - frustumCenter;
-        float distance = glm::length(offset) + 0.001f; // add 1mm to avoid divide by zero
-        float radius = avatar->getBoundingRadius();
-        const glm::vec3& forward = cameraView.getDirection();
-        float apparentSize = radius / distance;
-        float cosineAngle = glm::length(offset - glm::dot(offset, forward) * forward) / distance;
-        float age = (float)(now - avatar->getLastRenderUpdateTime()) / (float)(USECS_PER_SECOND);
-        float priority = 2.0f * apparentSize + 0.25f * cosineAngle + age;
-
-        // decrement priority of avatars outside keyhole
-        if (distance > cameraView.getCenterRadius()) {
-            if (!cameraView.sphereIntersectsFrustum(avatarPosition, radius)) {
-                priority += OUT_OF_VIEW_PENALTY;
+    {
+        PROFILE_RANGE(simulation, "sort");
+        for (int32_t i = 0; i < avatarList.size(); ++i) {
+            const auto& avatar = std::static_pointer_cast<Avatar>(avatarList.at(i));
+            if (avatar == _myAvatar || !avatar->isInitialized()) {
+                // DO NOT update _myAvatar!  Its update has already been done earlier in the main loop.
+                // DO NOT update or fade out uninitialized Avatars
+                continue;
             }
+            if (avatar->shouldDie()) {
+                removeAvatar(avatar->getID());
+                continue;
+            }
+            if (avatar->isDead()) {
+                continue;
+            }
+
+            // priority = weighted linear combination of:
+            //   (a) apparentSize
+            //   (b) proximity to center of view
+            //   (c) time since last update
+            //   (d) TIME_PENALTY to help recently updated entries sort toward back
+            glm::vec3 avatarPosition = avatar->getPosition();
+            glm::vec3 offset = avatarPosition - frustumCenter;
+            float distance = glm::length(offset) + 0.001f; // add 1mm to avoid divide by zero
+            float radius = avatar->getBoundingRadius();
+            const glm::vec3& forward = cameraView.getDirection();
+            float apparentSize = radius / distance;
+            float cosineAngle = glm::length(offset - glm::dot(offset, forward) * forward) / distance;
+            const float TIME_PENALTY = 0.080f; // seconds
+            float age = (float)(startTime - avatar->getLastRenderUpdateTime()) / (float)(USECS_PER_SECOND) - TIME_PENALTY;
+            float priority = apparentSize + 0.25f * cosineAngle + age;
+
+            // decrement priority of avatars outside keyhole
+            if (distance > cameraView.getCenterRadius()) {
+                if (!cameraView.sphereIntersectsFrustum(avatarPosition, radius)) {
+                    priority += OUT_OF_VIEW_PENALTY;
+                }
+            }
+            sortedAvatars.push(AvatarPriority(avatar, priority));
         }
-        sortedAvatars.push(AvatarPriority(avatar, priority));
     }
 
     render::PendingChanges pendingChanges;
-    const uint64_t AVATAR_RENDER_UPDATE_TIME_BUDGET = 2 * USECS_PER_MSEC;
-    uint64_t expiry = now + AVATAR_RENDER_UPDATE_TIME_BUDGET;
+    // NOTE: the copy of hash and sort above takes about 300 usec 
+    const uint64_t RENDER_UPDATE_BUDGET = 1500; // usec
+    const uint64_t MAX_UPDATE_BUDGET = 2000; // usec
+    uint64_t renderExpiry = startTime + RENDER_UPDATE_BUDGET;
+    uint64_t maxExpiry = startTime + MAX_UPDATE_BUDGET;
+    size_t numAvatarsProcessed = sortedAvatars.size();
     while (!sortedAvatars.empty()) {
         const AvatarPriority& sortData = sortedAvatars.top();
         const auto& avatar = std::static_pointer_cast<Avatar>(sortData.avatar);
@@ -225,12 +231,23 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
         }
         avatar->animateScaleChanges(deltaTime);
 
-        // for avatars in view...
-        const bool inView = sortData.priority > 0.5f * OUT_OF_VIEW_PENALTY;
-        avatar->simulate(deltaTime, inView);
-        if (expiry > usecTimestampNow()) {
+        uint64_t now = usecTimestampNow();
+        if (now < renderExpiry) {
+            // we're within budget
+            bool inView = sortData.priority > 0.5f * OUT_OF_VIEW_PENALTY;
+            avatar->simulate(deltaTime, inView);
             avatar->updateRenderItem(pendingChanges);
-            avatar->setLastRenderUpdateTime(now);
+            avatar->setLastRenderUpdateTime(startTime);
+        } else if (now < maxExpiry) {
+            // we've spent most of our time budget, but we still simulate() the avatar as it if were out of view
+            // --> some avatars may freeze until their priority trickles up
+            const bool inView = false;
+            avatar->simulate(deltaTime, inView);
+        } else {
+            // we've spent ALL of our time budget --> bail on the rest of the avatar updates
+            // --> some scale or fade animations may glitch
+            // --> some avatar velocity measurements may be a little off
+            break;
         }
         sortedAvatars.pop();
     }
@@ -238,8 +255,9 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
 
     simulateAvatarFades(deltaTime);
 
-    //PROFILE_COUNTER(simulation_avatar, "NumAvatarsPerSec",
-    //        { { "NumAvatarsPerSec", (float)((size() - sortedAvatars.size()) * USECS_PER_SECOND) / (float)(usecTimestampNow() - now) } });
+    numAvatarsProcessed -= sortedAvatars.size();
+    float numAvatarsPerSec = (float)(numAvatarsProcessed * USECS_PER_SECOND) / (float)(usecTimestampNow() - startTime);
+    PROFILE_COUNTER(simulation_avatar, "NumAvatarsPerSec", { { "NumAvatarsPerSec", numAvatarsPerSec } });
     PROFILE_COUNTER(simulation_avatar, "NumJointsPerSec", { { "NumJointsPerSec", Avatar::getNumJointsProcessedPerSecond() } });
 }
 
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index 54f6682191..4b77323bba 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -220,15 +220,19 @@ void SkeletonModel::updateAttitude() {
 // Called by Avatar::simulate after it has set the joint states (fullUpdate true if changed),
 // but just before head has been simulated.
 void SkeletonModel::simulate(float deltaTime, bool fullUpdate) {
-    updateAttitude();
-    setBlendshapeCoefficients(_owningAvatar->getHead()->getBlendshapeCoefficients());
+    if (fullUpdate) {
+        updateAttitude();
+        setBlendshapeCoefficients(_owningAvatar->getHead()->getBlendshapeCoefficients());
 
-    Model::simulate(deltaTime, fullUpdate);
+        Model::simulate(deltaTime, fullUpdate);
 
-    // let rig compute the model offset
-    glm::vec3 registrationPoint;
-    if (_rig->getModelRegistrationPoint(registrationPoint)) {
-        setOffset(registrationPoint);
+        // let rig compute the model offset
+        glm::vec3 registrationPoint;
+        if (_rig->getModelRegistrationPoint(registrationPoint)) {
+            setOffset(registrationPoint);
+        }
+    } else {
+        Model::simulate(deltaTime, fullUpdate);
     }
 
     if (!isActive() || !_owningAvatar->isMyAvatar()) {

From 01e14eec471cb65eb6aa8bb97851b69e52c490d5 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Tue, 24 Jan 2017 12:09:03 -0800
Subject: [PATCH 13/17] remove commented out cruft

---
 interface/src/avatar/AvatarManager.cpp | 17 -----------------
 interface/src/avatar/AvatarManager.h   |  2 --
 2 files changed, 19 deletions(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 73f3fb0f38..fe0b49728b 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -467,23 +467,6 @@ void AvatarManager::handleCollisionEvents(const CollisionEvents& collisionEvents
     }
 }
 
-/*
-void AvatarManager::addAvatarToSimulation(Avatar* avatar) {
-    assert(!avatar->getMotionState());
-
-    ShapeInfo shapeInfo;
-    avatar->computeShapeInfo(shapeInfo);
-    btCollisionShape* shape = const_cast<btCollisionShape*>(ObjectMotionState::getShapeManager()->getShape(shapeInfo));
-    if (shape) {
-        // we don't add to the simulation now, we put it on a list to be added later
-        AvatarMotionState* motionState = new AvatarMotionState(avatar, shape);
-        avatar->setMotionState(motionState);
-        _motionStatesToAddToPhysics.insert(motionState);
-        _motionStatesThatMightUpdate.insert(motionState);
-    }
-}
-*/
-
 void AvatarManager::updateAvatarRenderStatus(bool shouldRenderAvatars) {
     if (DependencyManager::get<SceneScriptingInterface>()->shouldRenderAvatars()) {
         for (auto avatarData : _avatarHash) {
diff --git a/interface/src/avatar/AvatarManager.h b/interface/src/avatar/AvatarManager.h
index efb01e071f..817a3e580f 100644
--- a/interface/src/avatar/AvatarManager.h
+++ b/interface/src/avatar/AvatarManager.h
@@ -69,8 +69,6 @@ public:
     void handleOutgoingChanges(const VectorOfMotionStates& motionStates);
     void handleCollisionEvents(const CollisionEvents& collisionEvents);
 
-    //void addAvatarToSimulation(Avatar* avatar);
-
     Q_INVOKABLE RayToAvatarIntersectionResult findRayIntersection(const PickRay& ray,
                                                                   const QScriptValue& avatarIdsToInclude = QScriptValue(),
                                                                   const QScriptValue& avatarIdsToDiscard = QScriptValue());

From 0f09e60acdcc8dc872609cad7ca88fc7366fe0e1 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Tue, 24 Jan 2017 12:13:01 -0800
Subject: [PATCH 14/17] remove unhelpful comment

---
 interface/src/avatar/AvatarManager.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index fe0b49728b..ff7180f95e 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -205,7 +205,6 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     }
 
     render::PendingChanges pendingChanges;
-    // NOTE: the copy of hash and sort above takes about 300 usec 
     const uint64_t RENDER_UPDATE_BUDGET = 1500; // usec
     const uint64_t MAX_UPDATE_BUDGET = 2000; // usec
     uint64_t renderExpiry = startTime + RENDER_UPDATE_BUDGET;

From 2264c2960443fd6591007ec06277e69b6709cd89 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Tue, 24 Jan 2017 14:22:39 -0800
Subject: [PATCH 15/17] less magic

---
 interface/src/avatar/AvatarManager.cpp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index ff7180f95e..4eac5bc2a4 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -192,6 +192,10 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
             float cosineAngle = glm::length(offset - glm::dot(offset, forward) * forward) / distance;
             const float TIME_PENALTY = 0.080f; // seconds
             float age = (float)(startTime - avatar->getLastRenderUpdateTime()) / (float)(USECS_PER_SECOND) - TIME_PENALTY;
+            // NOTE: we are adding values of different units to get a single measure of "priority".
+            // Thus we multiply each component by a conversion "weight" that scales its units
+            // relative to the others.  These weights are pure magic tuning and are hard coded in the
+            // relation below: (hint: unitary weights are not explicityly shown)
             float priority = apparentSize + 0.25f * cosineAngle + age;
 
             // decrement priority of avatars outside keyhole
@@ -233,7 +237,8 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
         uint64_t now = usecTimestampNow();
         if (now < renderExpiry) {
             // we're within budget
-            bool inView = sortData.priority > 0.5f * OUT_OF_VIEW_PENALTY;
+            const float OUT_OF_VIEW_THRESHOLD = 0.5f * OUT_OF_VIEW_PENALTY;
+            bool inView = sortData.priority > OUT_OF_VIEW_THRESHOLD;
             avatar->simulate(deltaTime, inView);
             avatar->updateRenderItem(pendingChanges);
             avatar->setLastRenderUpdateTime(startTime);

From 82f52b9658e3dd41f1014b2f24ab23f13c53ffd8 Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Wed, 25 Jan 2017 10:52:12 -0800
Subject: [PATCH 16/17] fix bug: Avatar instance not getting deleted

---
 interface/src/avatar/AvatarManager.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 4eac5bc2a4..658ee8ed97 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -285,6 +285,7 @@ void AvatarManager::simulateAvatarFades(float deltaTime) {
     while (fadingIterator != _avatarFades.end()) {
         auto avatar = std::static_pointer_cast<Avatar>(*fadingIterator);
         avatar->setTargetScale(avatar->getUniformScale() * SHRINK_RATE);
+        avatar->animateScaleChanges(deltaTime);
         if (avatar->getTargetScale() <= MIN_FADE_SCALE) {
             avatar->removeFromScene(*fadingIterator, scene, pendingChanges);
             // only remove from _avatarFades if we're sure its motionState has been removed from PhysicsEngine

From 5783db910bc20098469d23fd59e856540fe8690e Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Wed, 25 Jan 2017 10:57:48 -0800
Subject: [PATCH 17/17] remove some unhelpful trace profiling data

---
 interface/src/avatar/Avatar.cpp        | 16 ----------------
 interface/src/avatar/Avatar.h          |  2 --
 interface/src/avatar/AvatarManager.cpp |  6 ------
 3 files changed, 24 deletions(-)

diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index cdf9323ace..7ab1e7e8bd 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -85,19 +85,6 @@ namespace render {
     }
 }
 
-static uint64_t timeProcessingJoints = 0;
-static int32_t numJointsProcessed = 0;
-
-float Avatar::getNumJointsProcessedPerSecond() {
-    float rate = 0.0f;
-    if (timeProcessingJoints > 0) {
-        rate = (float)(numJointsProcessed * USECS_PER_SECOND) / (float)timeProcessingJoints;
-    }
-    timeProcessingJoints = 0;
-    numJointsProcessed = 0;
-    return rate;
-}
-
 Avatar::Avatar(RigPointer rig) :
     AvatarData(),
     _skeletonOffset(0.0f),
@@ -324,11 +311,8 @@ void Avatar::simulate(float deltaTime, bool inView) {
     {
         PROFILE_RANGE(simulation, "updateJoints");
         if (inView && _hasNewJointData) {
-            uint64_t start = usecTimestampNow();
             _skeletonModel->getRig()->copyJointsFromJointData(_jointData);
             _skeletonModel->simulate(deltaTime, true);
-            timeProcessingJoints += usecTimestampNow() - start;
-            numJointsProcessed += _jointData.size();
 
             locationChanged(); // joints changed, so if there are any children, update them.
             _hasNewJointData = false;
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index a6c5bbf16f..8f2b0817c1 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -58,8 +58,6 @@ class Avatar : public AvatarData {
     Q_PROPERTY(glm::vec3 skeletonOffset READ getSkeletonOffset WRITE setSkeletonOffset)
 
 public:
-    static float getNumJointsProcessedPerSecond();
-
     explicit Avatar(RigPointer rig = nullptr);
     ~Avatar();
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 658ee8ed97..2d0860b355 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -213,7 +213,6 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     const uint64_t MAX_UPDATE_BUDGET = 2000; // usec
     uint64_t renderExpiry = startTime + RENDER_UPDATE_BUDGET;
     uint64_t maxExpiry = startTime + MAX_UPDATE_BUDGET;
-    size_t numAvatarsProcessed = sortedAvatars.size();
     while (!sortedAvatars.empty()) {
         const AvatarPriority& sortData = sortedAvatars.top();
         const auto& avatar = std::static_pointer_cast<Avatar>(sortData.avatar);
@@ -258,11 +257,6 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
     qApp->getMain3DScene()->enqueuePendingChanges(pendingChanges);
 
     simulateAvatarFades(deltaTime);
-
-    numAvatarsProcessed -= sortedAvatars.size();
-    float numAvatarsPerSec = (float)(numAvatarsProcessed * USECS_PER_SECOND) / (float)(usecTimestampNow() - startTime);
-    PROFILE_COUNTER(simulation_avatar, "NumAvatarsPerSec", { { "NumAvatarsPerSec", numAvatarsPerSec } });
-    PROFILE_COUNTER(simulation_avatar, "NumJointsPerSec", { { "NumJointsPerSec", Avatar::getNumJointsProcessedPerSecond() } });
 }
 
 void AvatarManager::postUpdate(float deltaTime) {