Add LOD culling to the server protocol.

- Add LOD/distance culling to VoxelTree:encodeTreeBitstreamRecursion()
  and VoxelTree::searchForColoredNodesRecursion()
- added new levels to boundaryDistanceForRenderLevel()
- added more spheres to the scene to get a better sense of LOD behavior

interface/src/VoxelSystem.cpp

@@ -55,10 +55,6 @@ VoxelSystem::~VoxelSystem() {
     pthread_mutex_destroy(&bufferWriteLock);
 }
 
-void VoxelSystem::setViewerAvatar(Avatar *newViewerAvatar) {
-    viewerAvatar = newViewerAvatar;
-}
-
 //////////////////////////////////////////////////////////////////////////////////////////
 // Method:      VoxelSystem::loadVoxelsFile()
 // Description: Loads HiFidelity encoded Voxels from a binary file. The current file
@@ -180,7 +176,7 @@ void VoxelSystem::copyWrittenDataToReadArrays() {
 int VoxelSystem::treeToArrays(VoxelNode* currentNode, const glm::vec3&  nodePosition) {
     int voxelsAdded = 0;
     float halfUnitForVoxel = powf(0.5, *currentNode->octalCode) * (0.5 * TREE_SCALE);
-    glm::vec3 viewerPosition = viewerAvatar->getPosition();
+    glm::vec3 viewerPosition = _camera->getPosition(); //_viewerAvatar->getPosition();
 
     // debug LOD code
     glm::vec3 debugNodePosition;

interface/src/VoxelSystem.h

@@ -16,6 +16,7 @@
 #include <VoxelTree.h>
 #include <ViewFrustum.h>
 #include "Avatar.h"
+#include "Camera.h"
 #include "Util.h"
 #include "world.h"
 
@@ -34,7 +35,8 @@ public:
     void render();
     void setVoxelsRendered(int v) {voxelsRendered = v;};
     int getVoxelsRendered() {return voxelsRendered;};
-    void setViewerAvatar(Avatar *newViewerAvatar);
+    void setViewerAvatar(Avatar *newViewerAvatar) { _viewerAvatar = newViewerAvatar; };
+    void setCamera(Camera* newCamera) { _camera = newCamera; };
     void loadVoxelsFile(const char* fileName,bool wantColorRandomizer);
 	void createSphere(float r,float xc, float yc, float zc, float s, bool solid, bool wantColorRandomizer);
 
@@ -67,7 +69,8 @@ private:
     static float _minDistance;
 
     int voxelsRendered;
-    Avatar *viewerAvatar;
+    Avatar* _viewerAvatar;
+    Camera* _camera;
     VoxelTree *tree;
     GLfloat *readVerticesArray;
     GLubyte *readColorsArray;

interface/src/main.cpp

@@ -299,6 +299,7 @@ void init(void)
 {
     voxels.init();
     voxels.setViewerAvatar(&myAvatar);
+    voxels.setCamera(&myCamera);
     
     handControl.setScreenDimensions(WIDTH, HEIGHT);
 

libraries/voxels/src/VoxelTree.cpp

@@ -84,9 +84,27 @@ int boundaryDistanceForRenderLevel(unsigned int renderLevel) {
         case 7:
             return 12;
             break;
-        default:
+        case 8:
+            return 10;
+            break;
+        case 9:
             return 6;
             break;
+        case 10:
+            return 4.5;
+            break;
+        case 11:
+            return 3;
+            break;
+        case 12:
+            return 2.25;
+            break;
+        case 13:
+            return 1.5;
+            break;
+        default:
+            return 1;
+            break;
     }
 }
 
@@ -817,10 +835,12 @@ int VoxelTree::searchForColoredNodesRecursion(int maxSearchLevel, int& currentSe
             }
         
             float distance = childNode->distanceToCamera(viewFrustum);
-
-            inViewCount = insertIntoSortedArrays((void*)childNode, distance, i, 
-                                (void**)&inViewChildren, (float*)&distancesToChildren, (int*)&positionOfChildren,
-                                inViewCount, MAX_CHILDREN);
+            
+            if (distance < boundaryDistanceForRenderLevel(*childNode->octalCode + 1)) {
+                inViewCount = insertIntoSortedArrays((void*)childNode, distance, i, 
+                                    (void**)&inViewChildren, (float*)&distancesToChildren, (int*)&positionOfChildren,
+                                    inViewCount, MAX_CHILDREN);
+            }
         }
     }
 
@@ -920,6 +940,14 @@ int VoxelTree::encodeTreeBitstreamRecursion(int maxEncodeLevel, int& currentEnco
         return bytesAtThisLevel;
     }
 
+    float distance = node->distanceToCamera(viewFrustum);
+    float boundaryDistance = boundaryDistanceForRenderLevel(*node->octalCode + 1);
+
+    // If we're too far away for our render level, then just return
+    if (distance >= boundaryDistance) {
+        return bytesAtThisLevel;
+    }
+
     // If we're at a node that is out of view, then we can return, because no nodes below us will be in view!
     // although technically, we really shouldn't ever be here, because our callers shouldn't be calling us if
     // we're out of view
@@ -954,26 +982,28 @@ int VoxelTree::encodeTreeBitstreamRecursion(int maxEncodeLevel, int& currentEnco
     for (int i = 0; i < MAX_CHILDREN; i++) {
         VoxelNode* childNode = node->children[i];
         bool childExists = (childNode != NULL);
-        
-        bool childIsColored = (childExists && childNode->isColored());
         bool childIsInView  = (childExists && childNode->isInView(viewFrustum));
-        bool childIsLeaf    = (childExists && childNode->isLeaf());
-        
         if (childIsInView) {
-            inViewCount++;
+            // Before we determine consider this further, let's see if it's in our LOD scope...
+            float distance = childNode->distanceToCamera(viewFrustum);
+            float boundaryDistance = boundaryDistanceForRenderLevel(*childNode->octalCode + 1);
+
+            if (distance < boundaryDistance) {
+                inViewCount++;
             
-            // track children in view as existing and not a leaf, if they're a leaf,
-            // we don't care about recursing deeper on them, and we don't consider their
-            // subtree to exist
-            if (!childIsLeaf) {
-                childrenExistBits += (1 << (7 - i));
-                inViewNotLeafCount++;
-            }
+                // track children in view as existing and not a leaf, if they're a leaf,
+                // we don't care about recursing deeper on them, and we don't consider their
+                // subtree to exist
+                if (!(childExists && childNode->isLeaf())) {
+                    childrenExistBits += (1 << (7 - i));
+                    inViewNotLeafCount++;
+                }
             
-            // track children with actual color
-            if (childIsColored) {
-                childrenColoredBits += (1 << (7 - i));
-                inViewWithColorCount++;
+                // track children with actual color
+                if (childExists && childNode->isColored()) {
+                    childrenColoredBits += (1 << (7 - i));
+                    inViewWithColorCount++;
+                }
             }
         }
     }
@@ -1016,7 +1046,6 @@ int VoxelTree::encodeTreeBitstreamRecursion(int maxEncodeLevel, int& currentEnco
         // of handling things. For example, in case of child iteration, it needs to unset the child exist bit for
         // this child.
         // add our node the the list of extra nodes to output later... 
-
         bag.insert(node);
         return 0;
     }

voxel-server/src/main.cpp

@@ -38,7 +38,7 @@ const float DEATH_STAR_RADIUS = 4.0;
 const float MAX_CUBE = 0.05f;
 
 const int VOXEL_SEND_INTERVAL_USECS = 100 * 1000;
-const int PACKETS_PER_CLIENT_PER_INTERVAL = 5;
+const int PACKETS_PER_CLIENT_PER_INTERVAL = 2;
 
 const int MAX_VOXEL_TREE_DEPTH_LEVELS = 4;
 
@@ -68,6 +68,16 @@ void addSphere(VoxelTree * tree,bool random, bool wantColorRandomizer) {
 	tree->createSphere(r,xc,yc,zc,s,solid,wantColorRandomizer);
 }
 
+int _nodeCount=0;
+bool countVoxelsOperation(VoxelNode* node, bool down, void* extraData) {
+    if (down) {
+        if (node->isColored()){
+            _nodeCount++;
+        }
+    }
+    return true; // keep going
+}
+
 void addSphereScene(VoxelTree * tree, bool wantColorRandomizer) {
 	printf("adding scene of spheres...\n");
 	
@@ -80,6 +90,8 @@ void addSphereScene(VoxelTree * tree, bool wantColorRandomizer) {
 	tree->createSphere(0.25,0.5,0.5,0.5,(1.0/sphereBaseSize),true,wantColorRandomizer);
 	printf("one sphere added...\n");
 	tree->createSphere(0.030625,0.5,0.5,(0.25-0.06125),(1.0/(sphereBaseSize*2)),true,true);
+
+
 	printf("two spheres added...\n");
 	tree->createSphere(0.030625,(1.0-0.030625),(1.0-0.030625),(1.0-0.06125),(1.0/(sphereBaseSize*2)),true,true);
 	printf("three spheres added...\n");
@@ -88,6 +100,25 @@ void addSphereScene(VoxelTree * tree, bool wantColorRandomizer) {
 	tree->createSphere(0.030625,(1.0-0.030625),0.06125,(1.0-0.06125),(1.0/(sphereBaseSize*2)),true,true);
 	printf("five spheres added...\n");
 	tree->createSphere(0.06125,0.125,0.125,(1.0-0.125),(1.0/(sphereBaseSize*2)),true,true);
+
+    float radius = 0.0125f;
+	printf("6 spheres added...\n");
+	tree->createSphere(radius,0.25,radius*5.0f,0.25,(1.0/(4096)),true,true);
+	printf("7 spheres added...\n");
+	tree->createSphere(radius,0.125,radius*5.0f,0.25,(1.0/(4096)),true,true);
+	printf("8 spheres added...\n");
+	tree->createSphere(radius,0.075,radius*5.0f,0.25,(1.0/(4096)),true,true);
+	printf("9 spheres added...\n");
+	tree->createSphere(radius,0.05,radius*5.0f,0.25,(1.0/(4096)),true,true);
+	printf("10 spheres added...\n");
+	tree->createSphere(radius,0.025,radius*5.0f,0.25,(1.0/(4096)),true,true);
+	printf("11 spheres added...\n");
+
+    _nodeCount=0;
+    tree->recurseTreeWithOperation(countVoxelsOperation);
+    printf("Nodes after adding scene %d nodes\n",_nodeCount);
+
+
 	printf("DONE adding scene of spheres...\n");
 }