USing a simpler halfTan test for culling

interface/src/LODManager.cpp

@@ -237,8 +237,14 @@ QString LODManager::getLODFeedbackText() {
 bool LODManager::shouldRender(const RenderArgs* args, const AABox& bounds) {
     // FIXME - eventually we want to use the render accuracy as an indicator for the level of detail
     // to use in rendering.
-    float renderAccuracy = calculateRenderAccuracy(args->getViewFrustum().getPosition(), bounds, args->_sizeScale, args->_boundaryLevelAdjust);
-    return (renderAccuracy > 0.0f);
+  //  float renderAccuracy = calculateRenderAccuracy(args->getViewFrustum().getPosition(), bounds, args->_sizeScale, args->_boundaryLevelAdjust);
+  //  return (renderAccuracy > 0.0f);
+
+    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);
+
 };
 
 void LODManager::setOctreeSizeScale(float sizeScale) {
@@ -325,3 +331,6 @@ float LODManager::getSolidAngleHalfTan() const {
     return getPerspectiveAccuracyAngleTan(_octreeSizeScale, _boundaryLevelAdjust);
 }
 
+float LODManager::getSolidAngle() const {
+    return glm::degrees(2.0 * atan(getSolidAngleHalfTan()));
+}

interface/src/LODManager.h

@@ -70,6 +70,7 @@ class LODManager : public QObject, public Dependency {
     Q_PROPERTY(float worldDetailQuality READ getWorldDetailQuality WRITE setWorldDetailQuality NOTIFY worldDetailQualityChanged)
 
     Q_PROPERTY(float solidAngleHalfTan READ getSolidAngleHalfTan)
+    Q_PROPERTY(float solidAngle READ getSolidAngle)
 
 public:
      
@@ -187,6 +188,7 @@ public:
     float getWorldDetailQuality() const;
 
     float getSolidAngleHalfTan() const;
+    float getSolidAngle() const;
 
 signals:
 

libraries/octree/src/OctreeUtils.cpp

@@ -79,9 +79,3 @@ float getOrthographicAccuracySize(float octreeSizeScale, int boundaryLevelAdjust
     const float smallestSize = 0.01f;
     return (smallestSize * MAX_VISIBILITY_DISTANCE_FOR_UNIT_ELEMENT) / boundaryDistanceForRenderLevel(boundaryLevelAdjust, octreeSizeScale);
 }
-
-bool isAngularSizeBigEnough(glm::vec3 position, const AACube& cube, float lodScaleFactor, float minDiameter) {
-    float distance = glm::distance(cube.calcCenter(), position) + MIN_VISIBLE_DISTANCE;
-    float angularDiameter = cube.getScale() / distance;
-    return angularDiameter > minDiameter * lodScaleFactor;
-}

libraries/octree/src/OctreeUtils.h

@@ -39,6 +39,4 @@ const float MIN_ELEMENT_ANGULAR_DIAMETER = 0.0043301f; // radians
 const float MIN_ENTITY_ANGULAR_DIAMETER = MIN_ELEMENT_ANGULAR_DIAMETER * SQRT_THREE;
 const float MIN_VISIBLE_DISTANCE = 0.0001f; // helps avoid divide-by-zero check
 
-bool isAngularSizeBigEnough(glm::vec3 position, const AACube& cube, float lodScaleFactor, float minDiameter);
-
 #endif // hifi_OctreeUtils_h

libraries/render-utils/src/RenderShadowTask.cpp

@@ -62,8 +62,8 @@ void RenderShadowTask::build(JobModel& task, const render::Varying& input, rende
 
     const auto fetchInput = FetchSpatialTree::Inputs(shadowCasterReceiverFilter, queryResolution).asVarying();
     const auto shadowSelection = task.addJob<FetchSpatialTree>("FetchShadowTree", fetchInput);
-    const auto selectionInputs = FetchSpatialSelection::Inputs(shadowSelection, shadowCasterReceiverFilter).asVarying();
-    const auto shadowItems = task.addJob<FetchSpatialSelection>("FetchShadowSelection", selectionInputs);
+    const auto selectionInputs = FilterSpatialSelection::Inputs(shadowSelection, shadowCasterReceiverFilter).asVarying();
+    const auto shadowItems = task.addJob<FilterSpatialSelection>("FilterShadowSelection", selectionInputs);
 
     // Cull objects that are not visible in camera view. Hopefully the cull functor only performs LOD culling, not
     // frustum culling or this will make shadow casters out of the camera frustum disappear.

libraries/render/src/render/CullTask.cpp

@@ -445,7 +445,7 @@ void ApplyCullFunctorOnItemBounds::run(const RenderContextPointer& renderContext
     }
 }
 
-void FetchSpatialSelection::run(const RenderContextPointer& renderContext,
+void FilterSpatialSelection::run(const RenderContextPointer& renderContext,
                                const Inputs& inputs, ItemBounds& outItems) {
     assert(renderContext->args);
     auto& scene = renderContext->_scene;

libraries/render/src/render/CullTask.h

@@ -147,12 +147,12 @@ namespace render {
 
     };
 
-    class FetchSpatialSelection {
+    class FilterSpatialSelection {
     public:
         using Inputs = render::VaryingSet2<ItemSpatialTree::ItemSelection, ItemFilter>;
-        using JobModel = Job::ModelIO<FetchSpatialSelection, Inputs, ItemBounds>;
+        using JobModel = Job::ModelIO<FilterSpatialSelection, Inputs, ItemBounds>;
 
-        FetchSpatialSelection() {}
+        FilterSpatialSelection() {}
         void run(const RenderContextPointer& renderContext, const Inputs& inputs, ItemBounds& outItems);
     };
 

scripts/developer/utilities/render/lod.qml

@@ -160,15 +160,16 @@ Item {
             ]
         }
         PlotPerf {
-            title: "Solid Angle Half Tan"
+            title: "Solid Angle"
             height: parent.evalEvenHeight()
             object: LODManager
             valueScale: 1.0
-            valueUnit: ""
+            valueUnit: "deg"
+            //valueNumDigits: 0
             plots: [
                 {
-                    prop: "solidAngleHalfTan",
-                    label: "SAHT",
+                    prop: "solidAngle",
+                    label: "Solid Angle",
                     color: "#9999FF"
                 }
             ]