Exploring PID again

interface/src/LODManager.cpp

@@ -75,9 +75,41 @@ void LODManager::autoAdjustLOD(float realTimeDelta) {
         return;
     }
 
+    auto Kp = _pid.x;
+    auto Ki = _pid.y;
+    auto Kd = _pid.z;
+
     float oldOctreeSizeScale = _octreeSizeScale;
+    float oldSolidAngle = getSolidAngle();
+
+    float targetFPS = getLODDecreaseFPS();
+    float targetPeriod = 1.0f / targetFPS;
+
     float currentFPS = (float)MSECS_PER_SECOND / _avgRenderTime;
+    static uint64_t lastTime = usecTimestampNow();
     uint64_t now = usecTimestampNow();
+    auto dt = (float) ((now - lastTime) / double(USECS_PER_MSEC));
+    if (dt < targetPeriod * _pid.w) return;
+
+    float deltaFPS = currentFPS - getLODDecreaseFPS();
+    
+    lastTime = now;
+    auto previous_error = 0.f;
+    auto integral = 0.f;
+
+    auto error = getLODDecreaseFPS() - currentFPS;
+    integral = integral + error * dt;
+    auto derivative = (error - previous_error) / dt;
+    auto output = Kp * error + Ki * integral + Kd * derivative;
+    previous_error = error;
+
+    auto newSolidAngle = std::max( 0.1f, std::min(output, 45.f));
+
+    auto halTan = glm::tan(glm::radians(newSolidAngle * 0.5f));
+
+    auto octreeSizeScale = TREE_SCALE * OCTREE_TO_MESH_RATIO / halTan;
+    _octreeSizeScale = octreeSizeScale;
+/*
     if (currentFPS < getLODDecreaseFPS()) {
         if (now > _decreaseFPSExpiry) {
             _decreaseFPSExpiry = now + LOD_AUTO_ADJUST_PERIOD;
@@ -123,7 +155,7 @@ void LODManager::autoAdjustLOD(float realTimeDelta) {
         _increaseFPSExpiry = now + LOD_AUTO_ADJUST_PERIOD;
         _decreaseFPSExpiry = _increaseFPSExpiry;
     }
-
+*/
     if (oldOctreeSizeScale != _octreeSizeScale) {
         auto lodToolsDialog = DependencyManager::get<DialogsManager>()->getLodToolsDialog();
         if (lodToolsDialog) {
@@ -243,7 +275,7 @@ bool LODManager::shouldRender(const RenderArgs* args, const AABox& bounds) {
     auto pos = args->getViewFrustum().getPosition() - bounds.calcCenter();
     auto dim = bounds.getDimensions();
     auto halfTanSq = 0.25f * glm::dot(dim, dim) / glm::dot(pos, pos);
-    return (halfTanSq >= args->_solidAngleHalfTan * args->_solidAngleHalfTan);
+    return (halfTanSq >= args->_solidAngleHalfTanSq);
 
 };
 
@@ -279,10 +311,10 @@ void LODManager::setWorldDetailQuality(float quality) {
     bool isHMDMode = qApp->isHMDMode();
 
     float maxFPS = isHMDMode ? MAX_HMD_FPS : MAX_DESKTOP_FPS;
-    float desiredFPS = maxFPS - THRASHING_DIFFERENCE;
+    float desiredFPS = maxFPS /* - THRASHING_DIFFERENCE*/;
 
     if (!isLowestValue) {
-        float calculatedFPS = (maxFPS - (maxFPS * quality)) - THRASHING_DIFFERENCE;
+        float calculatedFPS = (maxFPS - (maxFPS * quality))/* - THRASHING_DIFFERENCE*/;
         desiredFPS = calculatedFPS < MIN_FPS ? MIN_FPS : calculatedFPS;
     }
 
@@ -315,14 +347,15 @@ float LODManager::getWorldDetailQuality() const {
         increaseFPS = getDesktopLODDecreaseFPS();
     }
     float maxFPS = inHMD ? MAX_HMD_FPS : MAX_DESKTOP_FPS;
-    float percentage = increaseFPS / maxFPS;
+    float percentage = 1.0 - increaseFPS / maxFPS;
 
-    if (percentage >= HIGH) {
+    if (percentage <= LOW) {
         return LOW;
     }
-    else if (percentage >= LOW) {
+    else if (percentage <= MEDIUM) {
         return MEDIUM;
     }
+
     return HIGH;
 }
 
@@ -334,3 +367,29 @@ float LODManager::getSolidAngleHalfTan() const {
 float LODManager::getSolidAngle() const {
     return glm::degrees(2.0 * atan(getSolidAngleHalfTan()));
 }
+
+
+float LODManager::getPidKp() const {
+    return _pid.x;
+}
+float LODManager::getPidKi() const {
+    return _pid.y;
+}
+float LODManager::getPidKd() const {
+    return _pid.z;
+}
+float LODManager::getPidT() const {
+    return _pid.w;
+}
+void LODManager::setPidKp(float k) {
+    _pid.x = k;
+}
+void LODManager::setPidKi(float k) {
+    _pid.y = k;
+}
+void LODManager::setPidKd(float k) {
+    _pid.z = k;
+}
+void LODManager::setPidT(float t) {
+    _pid.w = t;
+}

interface/src/LODManager.h

@@ -23,8 +23,8 @@ const float DEFAULT_DESKTOP_LOD_DOWN_FPS = 30.0f;
 const float DEFAULT_HMD_LOD_DOWN_FPS = 34.0f;
 const float DEFAULT_DESKTOP_MAX_RENDER_TIME = (float)MSECS_PER_SECOND / DEFAULT_DESKTOP_LOD_DOWN_FPS; // msec
 const float DEFAULT_HMD_MAX_RENDER_TIME = (float)MSECS_PER_SECOND / DEFAULT_HMD_LOD_DOWN_FPS; // msec
-const float MAX_LIKELY_DESKTOP_FPS = 59.0f; // this is essentially, V-synch - 1 fps
-const float MAX_LIKELY_HMD_FPS = 74.0f; // this is essentially, V-synch - 1 fps
+const float MAX_LIKELY_DESKTOP_FPS = 61.0f; // this is essentially, V-synch - 1 fps
+const float MAX_LIKELY_HMD_FPS = 91.0f; // this is essentially, V-synch - 1 fps
 const float INCREASE_LOD_GAP_FPS = 10.0f; // fps
 
 // The default value DEFAULT_OCTREE_SIZE_SCALE means you can be 400 meters away from a 1 meter object in order to see it (which is ~20:20 vision).
@@ -72,6 +72,12 @@ class LODManager : public QObject, public Dependency {
     Q_PROPERTY(float solidAngleHalfTan READ getSolidAngleHalfTan)
     Q_PROPERTY(float solidAngle READ getSolidAngle)
 
+    Q_PROPERTY(float pidKp READ getPidKp WRITE setPidKp)
+    Q_PROPERTY(float pidKi READ getPidKi WRITE setPidKi)
+    Q_PROPERTY(float pidKd READ getPidKd WRITE setPidKd)
+    Q_PROPERTY(float pidT READ getPidT WRITE setPidT)
+
+
 public:
      
     /**jsdoc
@@ -190,6 +196,15 @@ public:
     float getSolidAngleHalfTan() const;
     float getSolidAngle() const;
 
+    float getPidKp() const;
+    float getPidKi() const;
+    float getPidKd() const;
+    float getPidT() const;
+    void setPidKp(float k);
+    void setPidKi(float k);
+    void setPidKd(float k);
+    void setPidT(float t);
+
 signals:
 
     /**jsdoc
@@ -222,6 +237,8 @@ private:
     float _octreeSizeScale = DEFAULT_OCTREE_SIZE_SCALE;
     int _boundaryLevelAdjust = 0;
 
+    glm::vec4 _pid{ 0.1f, 0.0f, 0.0f, 3.0f };
+
     uint64_t _decreaseFPSExpiry { 0 };
     uint64_t _increaseFPSExpiry { 0 };
 };

libraries/render/src/render/Args.h

@@ -81,6 +81,7 @@ namespace render {
             _context(context),
             _sizeScale(sizeScale),
             _solidAngleHalfTan(solidAngleHalfTan),
+            _solidAngleHalfTanSq(solidAngleHalfTan * solidAngleHalfTan),
             _boundaryLevelAdjust(boundaryLevelAdjust),
             _renderMode(renderMode),
             _displayMode(displayMode),
@@ -111,6 +112,7 @@ namespace render {
         float _sizeScale { 1.0f };
         int _boundaryLevelAdjust { 0 };
         float _solidAngleHalfTan{ 0.1f };
+        float _solidAngleHalfTanSq{ _solidAngleHalfTan  * _solidAngleHalfTan };
 
         RenderMode _renderMode { DEFAULT_RENDER_MODE };
         DisplayMode _displayMode { MONO };

scripts/developer/utilities/render/lod.qml

@@ -78,6 +78,59 @@ Item {
             anchors.left: parent.left
             anchors.right: parent.right 
         }
+
+        RichSlider {
+            visible: LODManager.automaticLODAdjust
+            showLabel: true
+            label: "LOD PID Kp"
+            valueVar: LODManager["pidKp"]
+            valueVarSetter: (function (v) { LODManager["pidKp"] = v })
+            max: 1.0
+            min: 0.0
+            integral: false
+
+            anchors.left: parent.left
+            anchors.right: parent.right 
+        }
+        RichSlider {
+            visible: LODManager.automaticLODAdjust
+            showLabel: true
+            label: "LOD PID Ki"
+            valueVar: LODManager["pidKi"]
+            valueVarSetter: (function (v) { LODManager["pidKi"] = v })
+            max: 1.0
+            min: 0.0
+            integral: false
+
+            anchors.left: parent.left
+            anchors.right: parent.right 
+        }
+        RichSlider {
+            visible: LODManager.automaticLODAdjust
+            showLabel: true
+            label: "LOD PID Kd"
+            valueVar: LODManager["pidKd"]
+            valueVarSetter: (function (v) { LODManager["pidKd"] = v })
+            max: 1.0
+            min: 0.0
+            integral: false
+
+            anchors.left: parent.left
+            anchors.right: parent.right 
+        }
+        RichSlider {
+            visible: LODManager.automaticLODAdjust
+            showLabel: true
+            label: "LOD PID Num T"
+            valueVar: LODManager["pidT"]
+            valueVarSetter: (function (v) { LODManager["pidT"] = v })
+            max: 5.0
+            min: 0.0
+            integral: false
+
+            anchors.left: parent.left
+            anchors.right: parent.right 
+        }
     }
 
     Column {