diff --git a/KREngine/KREngine.xcodeproj/project.pbxproj b/KREngine/KREngine.xcodeproj/project.pbxproj
index d1c7fa2..f32a9a1 100644
--- a/KREngine/KREngine.xcodeproj/project.pbxproj
+++ b/KREngine/KREngine.xcodeproj/project.pbxproj
@@ -96,6 +96,10 @@
 		E491019D13C99BDC0098455B /* KRTextureManager.h in Headers */ = {isa = PBXBuildFile; fileRef = E491018513C99BDC0098455B /* KRTextureManager.h */; settings = {ATTRIBUTES = (); }; };
 		E491019E13C99BDC0098455B /* KRTexture.h in Headers */ = {isa = PBXBuildFile; fileRef = E491018613C99BDC0098455B /* KRTexture.h */; settings = {ATTRIBUTES = (); }; };
 		E49101A013C99BF50098455B /* OpenGLES.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = E491019F13C99BF50098455B /* OpenGLES.framework */; };
+		E4924C2615EE95E800B965C6 /* KROctree.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E4924C2415EE95E700B965C6 /* KROctree.cpp */; };
+		E4924C2715EE95E800B965C6 /* KROctree.h in Headers */ = {isa = PBXBuildFile; fileRef = E4924C2515EE95E800B965C6 /* KROctree.h */; };
+		E4924C2B15EE96AB00B965C6 /* KROctreeNode.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E4924C2915EE96AA00B965C6 /* KROctreeNode.cpp */; };
+		E4924C2C15EE96AB00B965C6 /* KROctreeNode.h in Headers */ = {isa = PBXBuildFile; fileRef = E4924C2A15EE96AA00B965C6 /* KROctreeNode.h */; };
 		E497B946151BA99500D3DC67 /* KRVector2.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E497B945151BA99400D3DC67 /* KRVector2.cpp */; };
 		E497B947151BA99500D3DC67 /* KRVector2.cpp in Sources */ = {isa = PBXBuildFile; fileRef = E497B945151BA99400D3DC67 /* KRVector2.cpp */; };
 		E497B948151BB89D00D3DC67 /* KRVector2.h in Headers */ = {isa = PBXBuildFile; fileRef = E497B943151BA93400D3DC67 /* KRVector2.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -234,6 +238,10 @@
 		E491018513C99BDC0098455B /* KRTextureManager.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; lineEnding = 0; name = KRTextureManager.h; path = Classes/KRTextureManager.h; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.objcpp; };
 		E491018613C99BDC0098455B /* KRTexture.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; lineEnding = 0; name = KRTexture.h; path = Classes/KRTexture.h; sourceTree = "<group>"; xcLanguageSpecificationIdentifier = xcode.lang.objcpp; };
 		E491019F13C99BF50098455B /* OpenGLES.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = OpenGLES.framework; path = System/Library/Frameworks/OpenGLES.framework; sourceTree = SDKROOT; };
+		E4924C2415EE95E700B965C6 /* KROctree.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = KROctree.cpp; path = Classes/KROctree.cpp; sourceTree = "<group>"; };
+		E4924C2515EE95E800B965C6 /* KROctree.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = KROctree.h; path = Classes/KROctree.h; sourceTree = "<group>"; };
+		E4924C2915EE96AA00B965C6 /* KROctreeNode.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = KROctreeNode.cpp; path = Classes/KROctreeNode.cpp; sourceTree = "<group>"; };
+		E4924C2A15EE96AA00B965C6 /* KROctreeNode.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = KROctreeNode.h; path = Classes/KROctreeNode.h; sourceTree = "<group>"; };
 		E497B943151BA93400D3DC67 /* KRVector2.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; name = KRVector2.h; path = Classes/KRVector2.h; sourceTree = "<group>"; };
 		E497B945151BA99400D3DC67 /* KRVector2.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = KRVector2.cpp; path = Classes/KRVector2.cpp; sourceTree = "<group>"; };
 		E497B949151BCEE900D3DC67 /* KRResource.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = KRResource.h; path = Classes/KRResource.h; sourceTree = "<group>"; };
@@ -437,6 +445,10 @@
 				E45772E313C99F160037BEEA /* Shaders */,
 				E491016E13C99BAE0098455B /* Classes */,
 				E491016713C99B9E0098455B /* Supporting Files */,
+				E4924C2415EE95E700B965C6 /* KROctree.cpp */,
+				E4924C2515EE95E800B965C6 /* KROctree.h */,
+				E4924C2915EE96AA00B965C6 /* KROctreeNode.cpp */,
+				E4924C2A15EE96AA00B965C6 /* KROctreeNode.h */,
 			);
 			path = KREngine;
 			sourceTree = "<group>";
@@ -568,6 +580,8 @@
 				E42CB1EC158446940066E0D8 /* KRQuaternion.h in Headers */,
 				E43B0ACB15DDBB8500A5CB9F /* KRNotified.h in Headers */,
 				E43B0AD815DDCA0F00A5CB9F /* KRContextObject.h in Headers */,
+				E4924C2715EE95E800B965C6 /* KROctree.h in Headers */,
+				E4924C2C15EE96AB00B965C6 /* KROctreeNode.h in Headers */,
 				1000469E15E6EF550053B072 /* KRSkyBox.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -727,6 +741,8 @@
 				E42CB1F0158446AB0066E0D8 /* KRQuaternion.cpp in Sources */,
 				E43B0AC915DDBB8500A5CB9F /* KRNotified.cpp in Sources */,
 				E43B0AD615DDCA0F00A5CB9F /* KRContextObject.cpp in Sources */,
+				E4924C2615EE95E800B965C6 /* KROctree.cpp in Sources */,
+				E4924C2B15EE96AB00B965C6 /* KROctreeNode.cpp in Sources */,
 				1000469D15E6EF550053B072 /* KRSkyBox.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
diff --git a/KREngine/KREngine/Classes/KRContext.cpp b/KREngine/KREngine/Classes/KRContext.cpp
index 0cb3876..9c18f4c 100644
--- a/KREngine/KREngine/Classes/KRContext.cpp
+++ b/KREngine/KREngine/Classes/KRContext.cpp
@@ -83,40 +83,4 @@ void KRContext::loadResource(std::string path) {
     } else {
         fprintf(stderr, "KRContext::loadResource - Unknown resource file type: %s\n", path.c_str());
     }
-}
-
-void KRContext::registerNotified(KRNotified *pNotified)
-{
-    m_notifiedObjects.insert(pNotified);
-    for(std::set<KRNode *>::iterator itr=m_allNodes.begin(); itr != m_allNodes.end(); itr++) {
-        pNotified->notify_sceneGraphCreate(*itr);
-    }
-}
-
-void KRContext::unregisterNotified(KRNotified *pNotified)
-{
-    m_notifiedObjects.erase(pNotified);
-}
-
-void KRContext::notify_sceneGraphCreate(KRNode *pNode)
-{
-    m_allNodes.insert(pNode);
-    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
-        (*itr)->notify_sceneGraphCreate(pNode);
-    }
-}
-
-void KRContext::notify_sceneGraphDelete(KRNode *pNode)
-{
-    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
-        (*itr)->notify_sceneGraphDelete(pNode);
-    }
-    m_allNodes.erase(pNode);
-}
-
-void KRContext::notify_sceneGraphModify(KRNode *pNode)
-{
-    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
-        (*itr)->notify_sceneGraphModify(pNode);
-    }
 }
\ No newline at end of file
diff --git a/KREngine/KREngine/Classes/KRContext.h b/KREngine/KREngine/Classes/KRContext.h
index 4b29af0..2f6cf21 100644
--- a/KREngine/KREngine/Classes/KRContext.h
+++ b/KREngine/KREngine/Classes/KRContext.h
@@ -31,22 +31,12 @@ public:
     
     KRCamera *createCamera(int width, int height);
     
-    void registerNotified(KRNotified *pNotified);
-    void unregisterNotified(KRNotified *pNotified);
-    
-    void notify_sceneGraphCreate(KRNode *pNode);
-    void notify_sceneGraphDelete(KRNode *pNode);
-    void notify_sceneGraphModify(KRNode *pNode);
-    
 private:
     KRSceneManager *m_pSceneManager;
     KRTextureManager *m_pTextureManager;
     KRMaterialManager *m_pMaterialManager;
     KRShaderManager *m_pShaderManager;
     KRModelManager *m_pModelManager;
-    
-    std::set<KRNotified *> m_notifiedObjects;
-    std::set<KRNode *> m_allNodes;
 };
 
 #endif
diff --git a/KREngine/KREngine/Classes/KRDirectionalLight.cpp b/KREngine/KREngine/Classes/KRDirectionalLight.cpp
index f660c06..3b41a4a 100644
--- a/KREngine/KREngine/Classes/KRDirectionalLight.cpp
+++ b/KREngine/KREngine/Classes/KRDirectionalLight.cpp
@@ -13,7 +13,7 @@
 #import "KRContext.h"
 #import "KRMat4.h"
 
-KRDirectionalLight::KRDirectionalLight(KRContext &context, std::string name) : KRLight(context, name)
+KRDirectionalLight::KRDirectionalLight(KRScene &scene, std::string name) : KRLight(scene, name)
 {
 
 }
diff --git a/KREngine/KREngine/Classes/KRDirectionalLight.h b/KREngine/KREngine/Classes/KRDirectionalLight.h
index 236c69e..593ac5a 100644
--- a/KREngine/KREngine/Classes/KRDirectionalLight.h
+++ b/KREngine/KREngine/Classes/KRDirectionalLight.h
@@ -16,7 +16,7 @@ class KRDirectionalLight : public KRLight {
     
 public:
     
-    KRDirectionalLight(KRContext &context, std::string name);
+    KRDirectionalLight(KRScene &scene, std::string name);
     virtual ~KRDirectionalLight();
     
     virtual std::string getElementName();
diff --git a/KREngine/KREngine/Classes/KRInstance.cpp b/KREngine/KREngine/Classes/KRInstance.cpp
index ab8bc9f..9aceb4f 100644
--- a/KREngine/KREngine/Classes/KRInstance.cpp
+++ b/KREngine/KREngine/Classes/KRInstance.cpp
@@ -32,9 +32,10 @@
 #include <iostream>
 #import "KRInstance.h"
 #import "KRContext.h"
+#import "KRMesh.h"
 #include <assert.h>
 
-KRInstance::KRInstance(KRContext &context, std::string instance_name, std::string model_name, const KRMat4 modelMatrix, std::string light_map) : KRNode(context, instance_name) {
+KRInstance::KRInstance(KRScene &scene, std::string instance_name, std::string model_name, const KRMat4 modelMatrix, std::string light_map) : KRNode(scene, instance_name) {
     m_modelMatrix = modelMatrix;
     m_lightMap = light_map;
     m_pLightMap = NULL;
@@ -68,9 +69,6 @@ KRMat4 &KRInstance::getModelMatrix() {
 void KRInstance::loadModel() {
     if(m_pModel == NULL) {
         m_pModel = m_pContext->getModelManager()->getModel(m_model_name.c_str());
-        if(m_pModel->hasTransparency()) {
-            m_pContext->notify_sceneGraphModify(this);
-        }
     }
 }
 
@@ -128,7 +126,7 @@ void KRInstance::calcExtents(KRContext *pContext) {
     KRNode::calcExtents(pContext);
     loadModel();    
     KRMesh *pMesh = m_pModel->getMesh();
-    KRBoundingVolume mesh_bounds = KRBoundingVolume(KRVector3(pMesh->getMinX(), pMesh->getMinY(), pMesh->getMinZ()), KRVector3(pMesh->getMaxX(), pMesh->getMaxY(), pMesh->getMaxZ()), m_modelMatrix);
+    KRBoundingVolume mesh_bounds = KRBoundingVolume(pMesh->getMinPoint(), pMesh->getMaxPoint(), m_modelMatrix);
     if(m_pExtents) {
         *m_pExtents = m_pExtents->get_union(mesh_bounds);
     } else {
@@ -142,5 +140,14 @@ bool KRInstance::hasTransparency() {
     } else {
         return false;
     }
-    
+}
+
+KRVector3 KRInstance::getMinPoint() {
+    loadModel();
+    return KRMat4::Dot(m_modelMatrix, m_pModel->getMesh()->getMinPoint());
+}
+
+KRVector3 KRInstance::getMaxPoint() {
+    loadModel();
+    return KRMat4::Dot(m_modelMatrix, m_pModel->getMesh()->getMaxPoint());
 }
\ No newline at end of file
diff --git a/KREngine/KREngine/Classes/KRInstance.h b/KREngine/KREngine/Classes/KRInstance.h
index a3844db..264e37b 100644
--- a/KREngine/KREngine/Classes/KRInstance.h
+++ b/KREngine/KREngine/Classes/KRInstance.h
@@ -53,7 +53,7 @@ class KRBoundingVolume;
 class KRInstance : public KRNode {
     
 public:
-    KRInstance(KRContext &context, std::string instance_name, std::string model_name, const KRMat4 modelMatrix, std::string light_map);
+    KRInstance(KRScene &scene, std::string instance_name, std::string model_name, const KRMat4 modelMatrix, std::string light_map);
     virtual ~KRInstance();
     
     virtual std::string getElementName();
@@ -70,6 +70,10 @@ public:
     
     bool hasTransparency();
     
+    
+    virtual KRVector3 getMinPoint();
+    virtual KRVector3 getMaxPoint();
+    
 private:
     KRModel *m_pModel;
     KRMat4 m_modelMatrix;
diff --git a/KREngine/KREngine/Classes/KRLight.cpp b/KREngine/KREngine/Classes/KRLight.cpp
index 7dd2512..91aebe0 100644
--- a/KREngine/KREngine/Classes/KRLight.cpp
+++ b/KREngine/KREngine/Classes/KRLight.cpp
@@ -22,7 +22,7 @@
 #import "KRShaderManager.h"
 #import "KRShader.h"
 
-KRLight::KRLight(KRContext &context, std::string name) : KRNode(context, name)
+KRLight::KRLight(KRScene &scene, std::string name) : KRNode(scene, name)
 {
     m_intensity = 1.0f;
     m_flareTexture = "";
diff --git a/KREngine/KREngine/Classes/KRLight.h b/KREngine/KREngine/Classes/KRLight.h
index 5425a12..806bf45 100644
--- a/KREngine/KREngine/Classes/KRLight.h
+++ b/KREngine/KREngine/Classes/KRLight.h
@@ -41,7 +41,7 @@ public:
 #endif
     
 protected:
-    KRLight(KRContext &context, std::string name);
+    KRLight(KRScene &scene, std::string name);
     
     float m_intensity;
     float m_decayStart;
diff --git a/KREngine/KREngine/Classes/KRMesh.cpp b/KREngine/KREngine/Classes/KRMesh.cpp
index 4549cf7..b3ba213 100644
--- a/KREngine/KREngine/Classes/KRMesh.cpp
+++ b/KREngine/KREngine/Classes/KRMesh.cpp
@@ -94,13 +94,8 @@ void KRMesh::loadPack(std::string path) {
                 m_iPackFileSize = statbuf.st_size;
                 
                 pack_header *pHeader = (pack_header *)m_pPackData;
-                
-                m_minx = pHeader->minx;
-                m_miny = pHeader->miny;
-                m_minz = pHeader->minz;
-                m_maxx = pHeader->maxx;
-                m_maxy = pHeader->maxy;
-                m_maxz = pHeader->maxz;
+                m_minPoint = KRVector3(pHeader->minx, pHeader->miny, pHeader->minz);
+                m_maxPoint = KRVector3(pHeader->maxx, pHeader->maxy, pHeader->maxz);
 
             }
         }
@@ -156,31 +151,12 @@ void KRMesh::unmap() {
 
 GLfloat KRMesh::getMaxDimension() {
     GLfloat m = 0.0;
-    if(m_maxx - m_minx > m) m = m_maxx - m_minx;
-    if(m_maxy - m_miny > m) m = m_maxy - m_miny;
-    if(m_maxz - m_minz > m) m = m_maxz - m_minz;
+    if(m_maxPoint.x - m_minPoint.x > m) m = m_maxPoint.x - m_minPoint.x;
+    if(m_maxPoint.y - m_minPoint.y > m) m = m_maxPoint.y - m_minPoint.y;
+    if(m_maxPoint.z - m_minPoint.z > m) m = m_maxPoint.z - m_minPoint.z;
     return m;
 }
 
-GLfloat KRMesh::getMinX() {
-    return m_minx;
-}
-GLfloat KRMesh::getMaxX() {
-    return m_maxx;
-}
-GLfloat KRMesh::getMinY() {
-    return m_miny;
-}
-GLfloat KRMesh::getMaxY() {
-    return m_maxy;
-}
-GLfloat KRMesh::getMinZ() {
-    return m_minz;
-}
-GLfloat KRMesh::getMaxZ() {
-    return m_maxz;
-}
-
 vector<KRMesh::Submesh *> KRMesh::getSubmeshes() {
     if(m_submeshes.size() == 0) {
         pack_header *pHeader = (pack_header *)m_pPackData;
@@ -301,19 +277,15 @@ void KRMesh::LoadData(std::vector<KRVector3> vertices, std::vector<KRVector2> uv
         pVertex->vertex.z = source_vertex.z;
         if(bFirstVertex) {
             bFirstVertex = false;
-            m_minx = source_vertex.x;
-            m_miny = source_vertex.y;
-            m_minz = source_vertex.z;
-            m_maxx = source_vertex.x;
-            m_maxy = source_vertex.y;
-            m_maxz = source_vertex.z;
+            m_minPoint = source_vertex;
+            m_maxPoint = source_vertex;
         } else {
-            if(source_vertex.x < m_minx) m_minx = source_vertex.x;
-            if(source_vertex.y < m_miny) m_miny = source_vertex.y;
-            if(source_vertex.z < m_minz) m_minz = source_vertex.z;
-            if(source_vertex.x > m_maxx) m_maxx = source_vertex.x;
-            if(source_vertex.y > m_maxy) m_maxy = source_vertex.y;
-            if(source_vertex.z > m_maxz) m_maxz = source_vertex.z;
+            if(source_vertex.x < m_minPoint.x) m_minPoint.x = source_vertex.x;
+            if(source_vertex.y < m_minPoint.y) m_minPoint.y = source_vertex.y;
+            if(source_vertex.z < m_minPoint.z) m_minPoint.z = source_vertex.z;
+            if(source_vertex.x > m_maxPoint.x) m_maxPoint.x = source_vertex.x;
+            if(source_vertex.y > m_maxPoint.y) m_maxPoint.y = source_vertex.y;
+            if(source_vertex.z > m_maxPoint.z) m_maxPoint.z = source_vertex.z;
         }
         if(uva.size() > iVertex) {
             KRVector2 source_uva = uva[iVertex];
@@ -355,12 +327,12 @@ void KRMesh::LoadData(std::vector<KRVector3> vertices, std::vector<KRVector2> uv
         pVertex++;
     }
     
-    pHeader->minx = m_minx;
-    pHeader->miny = m_miny;
-    pHeader->minz = m_minz;
-    pHeader->maxx = m_maxx;
-    pHeader->maxy = m_maxy;
-    pHeader->maxz = m_maxz;
+    pHeader->minx = m_minPoint.x;
+    pHeader->miny = m_minPoint.y;
+    pHeader->minz = m_minPoint.z;
+    pHeader->maxx = m_maxPoint.x;
+    pHeader->maxy = m_maxPoint.y;
+    pHeader->maxz = m_maxPoint.z;
     
     
     // Calculate missing surface normals and tangents
@@ -430,3 +402,10 @@ void KRMesh::LoadData(std::vector<KRVector3> vertices, std::vector<KRVector2> uv
     }
 }
 
+KRVector3 KRMesh::getMinPoint() const {
+    return m_minPoint;
+}
+
+KRVector3 KRMesh::getMaxPoint() const {
+    return m_maxPoint;
+}
\ No newline at end of file
diff --git a/KREngine/KREngine/Classes/KRMesh.h b/KREngine/KREngine/Classes/KRMesh.h
index 940db45..fa1f632 100644
--- a/KREngine/KREngine/Classes/KRMesh.h
+++ b/KREngine/KREngine/Classes/KRMesh.h
@@ -71,12 +71,9 @@ public:
     void renderSubmesh(int iSubmesh, int *iPrevBuffer);
     
     GLfloat getMaxDimension();
-    GLfloat getMinX();
-    GLfloat getMaxX();
-    GLfloat getMinY();
-    GLfloat getMaxY();
-    GLfloat getMinZ();
-    GLfloat getMaxZ();
+    
+    KRVector3 getMinPoint() const;
+    KRVector3 getMaxPoint() const;
     
     typedef struct {
         GLint start_vertex;
@@ -114,7 +111,7 @@ public:
     } pack_material;
     
 protected:
-    GLfloat m_minx, m_miny, m_minz, m_maxx, m_maxy, m_maxz;
+    KRVector3 m_minPoint, m_maxPoint;
 
     int m_fdPackFile;
     void *m_pPackData;
diff --git a/KREngine/KREngine/Classes/KRNode.cpp b/KREngine/KREngine/Classes/KRNode.cpp
index 397b9e9..271b175 100644
--- a/KREngine/KREngine/Classes/KRNode.cpp
+++ b/KREngine/KREngine/Classes/KRNode.cpp
@@ -8,6 +8,7 @@
 
 #include <iostream>
 #include <assert.h>
+#include <limits>
 
 #import "KRNode.h"
 #import "KRPointLight.h"
@@ -17,7 +18,7 @@
 #import "KRSkyBox.h"
 
 
-KRNode::KRNode(KRContext &context, std::string name) : KRContextObject(context)
+KRNode::KRNode(KRScene &scene, std::string name) : KRContextObject(scene.getContext())
 {
     m_pExtents = NULL;
     m_name = name;
@@ -25,10 +26,11 @@ KRNode::KRNode(KRContext &context, std::string name) : KRContextObject(context)
     m_localRotation = KRVector3::Zero();
     m_localTranslation = KRVector3::Zero();
     m_parentNode = NULL;
+    m_pScene = &scene;
 }
 
 KRNode::~KRNode() {
-    m_pContext->notify_sceneGraphDelete(this);
+    getScene().notify_sceneGraphDelete(this);
     for(std::vector<KRNode *>::iterator itr=m_childNodes.begin(); itr < m_childNodes.end(); ++itr) {
         delete *itr;
     }
@@ -41,7 +43,7 @@ void KRNode::addChild(KRNode *child) {
     child->m_parentNode = this;
     m_childNodes.push_back(child);
     clearExtents();
-    m_pContext->notify_sceneGraphCreate(child);
+    getScene().notify_sceneGraphCreate(child);
 }
 
 tinyxml2::XMLElement *KRNode::saveXML(tinyxml2::XMLNode *parent) {
@@ -84,7 +86,7 @@ void KRNode::loadXML(tinyxml2::XMLElement *e) {
     m_localRotation = KRVector3(x,y,z);
     
     for(tinyxml2::XMLElement *child_element=e->FirstChildElement(); child_element != NULL; child_element = child_element->NextSiblingElement()) {
-        KRNode *child_node = KRNode::LoadXML(*m_pContext, child_element);
+        KRNode *child_node = KRNode::LoadXML(getScene(), child_element);
         if(child_node) {
             addChild(child_node);
         }
@@ -129,22 +131,22 @@ std::string KRNode::getElementName() {
     return "node";
 }
 
-KRNode *KRNode::LoadXML(KRContext &context, tinyxml2::XMLElement *e) {
+KRNode *KRNode::LoadXML(KRScene &scene, tinyxml2::XMLElement *e) {
     KRNode *new_node = NULL;
     const char *szElementName = e->Name();
     const char *szName = e->Attribute("name");
     if(strcmp(szElementName, "node") == 0) {
-        new_node = new KRNode(context, szName);
+        new_node = new KRNode(scene, szName);
     } else if(strcmp(szElementName, "point_light") == 0) {
-        new_node = new KRPointLight(context, szName);
+        new_node = new KRPointLight(scene, szName);
     } else if(strcmp(szElementName, "directional_light") == 0) {
-        new_node = new KRDirectionalLight(context, szName);
+        new_node = new KRDirectionalLight(scene, szName);
     } else if(strcmp(szElementName, "spot_light") == 0) {
-        new_node = new KRSpotLight(context, szName);
+        new_node = new KRSpotLight(scene, szName);
     } else if(strcmp(szElementName, "mesh") == 0) {
-        new_node = new KRInstance(context, szName, szName, KRMat4(), e->Attribute("light_map"));
+        new_node = new KRInstance(scene, szName, szName, KRMat4(), e->Attribute("light_map"));
     } else if(strcmp(szElementName, "sky_box") == 0) {
-        new_node = new KRSkyBox(context, szName);
+        new_node = new KRSkyBox(scene, szName);
     }
     
     if(new_node) {
@@ -201,4 +203,17 @@ const std::vector<KRNode *> &KRNode::getChildren() {
 
 const std::string &KRNode::getName() {
     return m_name;
+}
+
+KRScene &KRNode::getScene() {
+    return *m_pScene;
+}
+
+
+KRVector3 KRNode::getMinPoint() {
+    return KRVector3::Min();
+}
+
+KRVector3 KRNode::getMaxPoint() {
+    return KRVector3::Max();
 }
\ No newline at end of file
diff --git a/KREngine/KREngine/Classes/KRNode.h b/KREngine/KREngine/Classes/KRNode.h
index 3296853..0b8e911 100644
--- a/KREngine/KREngine/Classes/KRNode.h
+++ b/KREngine/KREngine/Classes/KRNode.h
@@ -21,6 +21,7 @@ class KRMaterialManager;
 class KRMat4;
 class KRTextureManager;
 class KRContext;
+class KRScene;
 
 class KRNode : public KRContextObject
 {
@@ -36,11 +37,11 @@ public:
         RENDER_PASS_SKYBOX
     };
     
-    KRNode(KRContext &context, std::string name);
+    KRNode(KRScene &scene, std::string name);
     virtual ~KRNode();
     
     virtual tinyxml2::XMLElement *saveXML( tinyxml2::XMLNode *parent);
-    static KRNode *LoadXML(KRContext &context, tinyxml2::XMLElement *e);
+    static KRNode *LoadXML(KRScene &scene, tinyxml2::XMLElement *e);
     virtual void loadXML(tinyxml2::XMLElement *e);
     
     virtual std::string getElementName();
@@ -63,7 +64,12 @@ public:
     
     void clearExtents();
     virtual void calcExtents(KRContext *Context);
-    KRBoundingVolume getExtents(KRContext *pContext);    
+    KRBoundingVolume getExtents(KRContext *pContext);
+    
+    virtual KRVector3 getMinPoint();
+    virtual KRVector3 getMaxPoint();
+    
+    KRScene &getScene();
 #if TARGET_OS_IPHONE
     
     virtual void render(KRCamera *pCamera, KRContext *pContext, KRBoundingVolume &frustrumVolume, KRMat4 &viewMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, RenderPass renderPass);
@@ -83,6 +89,8 @@ private:
     std::vector<KRNode *> m_childNodes;
     KRNode *m_parentNode;
     
+    KRScene *m_pScene;
+    
 };
 
 
diff --git a/KREngine/KREngine/Classes/KRNotified.cpp b/KREngine/KREngine/Classes/KRNotified.cpp
index 9302ed8..83c3710 100644
--- a/KREngine/KREngine/Classes/KRNotified.cpp
+++ b/KREngine/KREngine/Classes/KRNotified.cpp
@@ -34,10 +34,13 @@
 
 KRNotified::KRNotified(KRContext &context) : KRContextObject(context)
 {
-    
+    m_pSubscribedScene = NULL;
 }
 
 KRNotified::~KRNotified()
 {
-    m_pContext->unregisterNotified(this);
+    if(m_pSubscribedScene) {
+        m_pSubscribedScene->unregisterNotified(this);
+        m_pSubscribedScene = NULL;
+    }
 }
diff --git a/KREngine/KREngine/Classes/KRNotified.h b/KREngine/KREngine/Classes/KRNotified.h
index 0491020..98de58e 100644
--- a/KREngine/KREngine/Classes/KRNotified.h
+++ b/KREngine/KREngine/Classes/KRNotified.h
@@ -36,6 +36,7 @@
 
 class KRContext;
 class KRNode;
+class KRScene;
 
 class KRNotified : public KRContextObject {
 
@@ -46,6 +47,8 @@ public:
     virtual void notify_sceneGraphCreate(KRNode *pNode) = 0;
     virtual void notify_sceneGraphDelete(KRNode *pNode) = 0;
     virtual void notify_sceneGraphModify(KRNode *pNode) = 0;
+private:
+    KRScene *m_pSubscribedScene;
 };
 
 #endif
diff --git a/KREngine/KREngine/Classes/KROctree.cpp b/KREngine/KREngine/Classes/KROctree.cpp
new file mode 100644
index 0000000..8f2464c
--- /dev/null
+++ b/KREngine/KREngine/Classes/KROctree.cpp
@@ -0,0 +1,84 @@
+//
+//  KROctree.cpp
+//  KREngine
+//
+//  Created by Kearwood Gilbert on 2012-08-29.
+//  Copyright (c) 2012 Kearwood Software. All rights reserved.
+//
+
+#include "KROctree.h"
+#include "KRNode.h"
+
+KROctree::KROctree()
+{
+    m_pRootNode = NULL;
+}
+
+KROctree::~KROctree()
+{
+    if(m_pRootNode) {
+        delete m_pRootNode;
+    }
+}
+
+void KROctree::add(KRNode *pNode)
+{
+    KRVector3 minPoint = pNode->getMinPoint();
+    KRVector3 maxPoint = pNode->getMaxPoint();
+    if(pNode->getMinPoint() == KRVector3::Min() && pNode->getMaxPoint() == KRVector3::Max()) {
+        // This item is infinitely large; we track it separately
+        m_outerSceneNodes.insert(pNode);
+    } else { 
+        if(m_pRootNode == NULL) {
+            // First item inserted, create a node large enough to fit it
+            m_pRootNode = new KROctreeNode(pNode->getMinPoint(), pNode->getMaxPoint());
+            m_pRootNode->add(pNode);
+        } else {
+            // Keep encapsulating the root node until the new root contains the inserted node
+            bool bInsideRoot = false;
+            while(!bInsideRoot) {
+                KRVector3 rootMinPoint = m_pRootNode->getMinPoint();
+                KRVector3 rootMaxPoint = m_pRootNode->getMaxPoint();
+                KRVector3 rootSize = rootMaxPoint - rootMinPoint;
+                if(minPoint.x < rootMinPoint.x || minPoint.y < rootMinPoint.y || minPoint.z < rootMinPoint.z) {
+                    m_pRootNode = new KROctreeNode(rootMinPoint - rootSize, rootMaxPoint, 7, m_pRootNode);
+                } else if(maxPoint.x > rootMaxPoint.x || maxPoint.y > rootMaxPoint.y || maxPoint.z > rootMaxPoint.z) {
+                    m_pRootNode = new KROctreeNode(rootMaxPoint, rootMaxPoint + rootSize, 0, m_pRootNode);
+                } else {
+                    bInsideRoot = true;
+                }
+            }
+            m_pRootNode->add(pNode);
+        }
+    }
+}
+
+void KROctree::remove(KRNode *pNode)
+{
+    if(!m_outerSceneNodes.erase(pNode)) {
+        if(m_pRootNode) {
+            m_pRootNode->remove(pNode);
+        }
+    }
+    
+    shrink();
+}
+
+void KROctree::update(KRNode *pNode)
+{
+    // TODO: This may be more efficient as an incremental operation rather than removing and re-adding the node
+    remove(pNode);
+    add(pNode);
+    shrink();
+}
+
+void KROctree::shrink()
+{
+    if(m_pRootNode) {
+        while(m_pRootNode->canShrinkRoot()) {
+            KROctreeNode *newRoot = m_pRootNode->stripChild();
+            delete m_pRootNode;
+            m_pRootNode = newRoot;
+        }
+    }
+}
diff --git a/KREngine/KREngine/Classes/KROctree.h b/KREngine/KREngine/Classes/KROctree.h
new file mode 100644
index 0000000..9ac49a6
--- /dev/null
+++ b/KREngine/KREngine/Classes/KROctree.h
@@ -0,0 +1,33 @@
+//
+//  KROctree.h
+//  KREngine
+//
+//  Created by Kearwood Gilbert on 2012-08-29.
+//  Copyright (c) 2012 Kearwood Software. All rights reserved.
+//
+
+#ifndef KRAABBTREE_H
+#define KRAABBTREE_H
+
+#import "KREngine-common.h"
+#include "KROctreeNode.h"
+
+class KRNode;
+
+class KROctree {
+public:
+    KROctree();
+    ~KROctree();
+    
+    void add(KRNode *pNode);
+    void remove(KRNode *pNode);
+    void update(KRNode *pNode);
+    
+private:
+    KROctreeNode *m_pRootNode;
+    std::set<KRNode *>m_outerSceneNodes;
+    
+    void shrink();
+};
+
+#endif /* defined(KRAABBTREE_H) */
diff --git a/KREngine/KREngine/Classes/KROctreeNode.cpp b/KREngine/KREngine/Classes/KROctreeNode.cpp
new file mode 100644
index 0000000..1040f38
--- /dev/null
+++ b/KREngine/KREngine/Classes/KROctreeNode.cpp
@@ -0,0 +1,172 @@
+//
+//  KROctreeNode.cpp
+//  KREngine
+//
+//  Created by Kearwood Gilbert on 2012-08-29.
+//  Copyright (c) 2012 Kearwood Software. All rights reserved.
+//
+
+#include "KROctreeNode.h"
+#include "KRNode.h"
+
+KROctreeNode::KROctreeNode(const KRVector3 &minPoint, const KRVector3 &maxPoint)
+{
+    m_minPoint = minPoint;
+    m_maxPoint = maxPoint;
+    for(int i=0; i<8; i++) m_children[i] = NULL;
+}
+
+KROctreeNode::KROctreeNode(const KRVector3 &minPoint, const KRVector3 &maxPoint, int iChild, KROctreeNode *pChild)
+{
+    // This constructor is used when expanding the octree and replacing the root node with a new root that encapsulates it
+    m_minPoint = minPoint;
+    m_maxPoint = maxPoint;
+    for(int i=0; i<8; i++) m_children[i] = NULL;
+    m_children[iChild] = pChild;
+}
+
+KROctreeNode::~KROctreeNode()
+{
+    for(int i=0; i<8; i++) {
+        if(m_children[i] != NULL) {
+            delete m_children[i];
+        }
+    }
+}
+
+void KROctreeNode::add(KRNode *pNode)
+{
+
+    
+    KRVector3 center = (m_minPoint + m_maxPoint) / 2.0f;
+    
+    int iChild = getChildIndex(pNode);
+    if(iChild == -1) {
+        m_sceneNodes.insert(pNode);
+    } else {
+        if(m_children[iChild] == NULL) {
+            m_children[iChild] = new KROctreeNode(
+                  KRVector3(
+                    (iChild & 1) == 0 ? m_minPoint.x : center.x,
+                    (iChild & 2) == 0 ? m_minPoint.y : center.y,
+                    (iChild & 4) == 0 ? m_minPoint.z : center.z),
+                  KRVector3(
+                    (iChild & 1) == 0 ? center.x : m_maxPoint.x,
+                    (iChild & 2) == 0 ? center.y : m_maxPoint.y,
+                    (iChild & 4) == 0 ? center.z : m_maxPoint.z)
+            );
+        }
+        m_children[iChild]->add(pNode);
+    }
+}
+
+int KROctreeNode::getChildIndex(KRNode *pNode)
+{
+    KRVector3 min = pNode->getMinPoint();
+    KRVector3 max = pNode->getMaxPoint();
+    // 0: max.x < center.x && max.y < center.y && max.z < center.z
+    // 1: min.x > center.x && max.y < center.y && max.z < center.z
+    // 2: max.x < center.x && min.y > center.y && max.z < center.z
+    // 3: min.x > center.x && min.y > center.y && max.z < center.z
+    // 4: max.x < center.x && max.y < center.y && min.z > center.z
+    // 5: min.x > center.x && max.y < center.y && min.z > center.z
+    // 6: max.x < center.x && min.y > center.y && min.z > center.z
+    // 7: min.x > center.x && min.y > center.y && min.z > center.z
+    
+    KRVector3 center = (m_minPoint + m_maxPoint) / 2.0f;
+    int iChild = -1;
+    if(max.z < center.z) {
+        if(max.y < center.y) {
+            if(max.x < center.x) {
+                iChild = 0;
+            } else if(min.x > center.x) {
+                iChild = 1;
+            }
+        } else if(min.y > center.y) {
+            if(max.x < center.x) {
+                iChild = 2;
+            } else if(min.x > center.x) {
+                iChild = 3;
+            }
+        }
+    } else if(min.z > center.z) {
+        if(max.y < center.y) {
+            if(min.x > center.x) {
+                iChild = 4;
+            } else if(min.x > center.x) {
+                iChild = 5;
+            }
+        } else if(min.y > center.y) {
+            if(max.x < center.x) {
+                iChild = 6;
+            } else if(min.x > center.x) {
+                iChild = 7;
+            }
+        }
+    }
+    return iChild;
+}
+
+void KROctreeNode::remove(KRNode *pNode)
+{
+    if(!m_sceneNodes.erase(pNode)) {
+        int iChild = getChildIndex(pNode);
+        if(m_children[iChild]) {
+            m_children[iChild]->remove(pNode);
+            if(m_children[iChild]->isEmpty()) {
+                delete m_children[iChild];
+                m_children[iChild] = NULL;
+            }
+        }
+    }
+}
+
+void KROctreeNode::update(KRNode *pNode)
+{
+    
+}
+
+KRVector3 KROctreeNode::getMinPoint()
+{
+    return m_minPoint;
+}
+
+KRVector3 KROctreeNode::getMaxPoint()
+{
+    return m_maxPoint;
+}
+
+bool KROctreeNode::isEmpty() const
+{
+    for(int i=0; i<8; i++) {
+        if(m_children[i]) {
+            return false;
+        }
+    }
+    return m_sceneNodes.empty();
+}
+
+bool KROctreeNode::canShrinkRoot() const
+{
+    int cChildren = 0;
+    for(int i=0; i<8; i++) {
+        if(m_children[i]) {
+            cChildren++;
+        }
+    }
+    return cChildren <= 1 && m_sceneNodes.empty();
+}
+
+KROctreeNode *KROctreeNode::stripChild()
+{
+    // Return the first found child and update its reference to NULL so that the destructor will not free it.  This is used for shrinking the octree
+    // NOTE: The caller of this function will be responsible for freeing the child object.  It is also possible to return a NULL
+    for(int i=0; i<8; i++) {
+        if(m_children[i]) {
+            KROctreeNode *child = m_children[i];
+            m_children[i] = NULL;
+            return child;
+        }
+    }
+    return NULL;
+}
diff --git a/KREngine/KREngine/Classes/KROctreeNode.h b/KREngine/KREngine/Classes/KROctreeNode.h
new file mode 100644
index 0000000..5bbb67f
--- /dev/null
+++ b/KREngine/KREngine/Classes/KROctreeNode.h
@@ -0,0 +1,47 @@
+//
+//  KROctreeNode.h
+//  KREngine
+//
+//  Created by Kearwood Gilbert on 2012-08-29.
+//  Copyright (c) 2012 Kearwood Software. All rights reserved.
+//
+
+#ifndef KRAABBTREENODE_H
+#define KRAABBTREENODE_H
+
+#import "KREngine-common.h"
+#include "KRVector3.h"
+
+class KRNode;
+
+class KROctreeNode {
+public:
+    KROctreeNode(const KRVector3 &minPoint, const KRVector3 &maxPoint);
+    KROctreeNode(const KRVector3 &minPoint, const KRVector3 &maxPoint, int iChild, KROctreeNode *pChild);
+    ~KROctreeNode();
+    
+    void add(KRNode *pNode);
+    void remove(KRNode *pNode);
+    void update(KRNode *pNode);
+    
+    KRVector3 getMinPoint();
+    KRVector3 getMaxPoint();
+    
+    void setChildNode(int iChild, KROctreeNode *pChild);
+    int getChildIndex(KRNode *pNode);
+    bool isEmpty() const;
+    
+    bool canShrinkRoot() const;
+    KROctreeNode *stripChild();
+    
+private:
+    KRVector3 m_minPoint;
+    KRVector3 m_maxPoint;
+    
+    KROctreeNode *m_children[8];
+    
+    std::set<KRNode *>m_sceneNodes;
+};
+
+
+#endif /* defined(KRAABBTREENODE_H) */
diff --git a/KREngine/KREngine/Classes/KRPointLight.cpp b/KREngine/KREngine/Classes/KRPointLight.cpp
index 9c5d426..ae8da4b 100644
--- a/KREngine/KREngine/Classes/KRPointLight.cpp
+++ b/KREngine/KREngine/Classes/KRPointLight.cpp
@@ -16,7 +16,7 @@
 #import "KRContext.h"
 #import "KRBoundingVolume.h"
 
-KRPointLight::KRPointLight(KRContext &context, std::string name) : KRLight(context, name)
+KRPointLight::KRPointLight(KRScene &scene, std::string name) : KRLight(scene, name)
 {
     m_sphereVertices = NULL;
     m_cVertices = 0;
diff --git a/KREngine/KREngine/Classes/KRPointLight.h b/KREngine/KREngine/Classes/KRPointLight.h
index 1ed3586..b6bc868 100644
--- a/KREngine/KREngine/Classes/KRPointLight.h
+++ b/KREngine/KREngine/Classes/KRPointLight.h
@@ -16,7 +16,7 @@ class KRPointLight : public KRLight {
     
 public:
     
-    KRPointLight(KRContext &context, std::string name);
+    KRPointLight(KRScene &scene, std::string name);
     virtual ~KRPointLight();
     
     virtual std::string getElementName();
diff --git a/KREngine/KREngine/Classes/KRScene.cpp b/KREngine/KREngine/Classes/KRScene.cpp
index 38b2f60..54ee3dd 100644
--- a/KREngine/KREngine/Classes/KRScene.cpp
+++ b/KREngine/KREngine/Classes/KRScene.cpp
@@ -42,7 +42,7 @@
 KRScene::KRScene(KRContext &context, std::string name) : KRResource(context, name) {
     m_pContext = &context;
     m_pFirstDirectionalLight = NULL;
-    m_pRootNode = new KRNode(context, "scene_root");
+    m_pRootNode = new KRNode(*this, "scene_root");
     
     sun_yaw = 4.333; // TODO - Remove temporary testing code
     sun_pitch = 0.55;
@@ -56,6 +56,8 @@ KRScene::~KRScene() {
 
 void KRScene::render(KRCamera *pCamera, KRContext *pContext, KRBoundingVolume &frustrumVolume, KRMat4 &viewMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRNode::RenderPass renderPass) {
     
+    updateOctree();
+    
     if(renderPass != KRNode::RENDER_PASS_SHADOWMAP) {
     
         if(cShadowBuffers > 0) {
@@ -145,7 +147,7 @@ KRScene *KRScene::LoadXML(KRContext &context, const std::string& path)
     doc.LoadFile(path.c_str());
     KRScene *new_scene = new KRScene(context, KRResource::GetFileBase(path));
     
-    KRNode *n = KRNode::LoadXML(context, doc.RootElement()->FirstChildElement());
+    KRNode *n = KRNode::LoadXML(*new_scene, doc.RootElement()->FirstChildElement());
     if(n) {
         new_scene->getRootNode()->addChild(n);
     }
@@ -159,3 +161,57 @@ KRDirectionalLight *KRScene::getFirstDirectionalLight()
     }
     return m_pFirstDirectionalLight;
 }
+
+void KRScene::registerNotified(KRNotified *pNotified)
+{
+    m_notifiedObjects.insert(pNotified);
+    for(std::set<KRNode *>::iterator itr=m_allNodes.begin(); itr != m_allNodes.end(); itr++) {
+        pNotified->notify_sceneGraphCreate(*itr);
+    }
+}
+
+void KRScene::unregisterNotified(KRNotified *pNotified)
+{
+    m_notifiedObjects.erase(pNotified);
+}
+
+void KRScene::notify_sceneGraphCreate(KRNode *pNode)
+{
+    m_allNodes.insert(pNode);
+    m_newNodes.insert(pNode);
+    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
+        (*itr)->notify_sceneGraphCreate(pNode);
+    }
+}
+
+void KRScene::notify_sceneGraphDelete(KRNode *pNode)
+{
+    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
+        (*itr)->notify_sceneGraphDelete(pNode);
+    }
+    m_allNodes.erase(pNode);
+    m_modifiedNodes.erase(pNode);
+    if(!m_newNodes.erase(pNode)) {
+        m_nodeTree.remove(pNode);
+    }
+}
+
+void KRScene::notify_sceneGraphModify(KRNode *pNode)
+{
+    m_modifiedNodes.insert(pNode);
+    for(std::set<KRNotified *>::iterator itr = m_notifiedObjects.begin(); itr != m_notifiedObjects.end(); itr++) {
+        (*itr)->notify_sceneGraphModify(pNode);
+    }
+}
+
+void KRScene::updateOctree()
+{
+    for(std::set<KRNode *>::iterator itr=m_newNodes.begin(); itr != m_newNodes.end(); itr++) {
+        m_nodeTree.add(*itr);
+    }
+    for(std::set<KRNode *>::iterator itr=m_modifiedNodes.begin(); itr != m_modifiedNodes.end(); itr++) {
+        m_nodeTree.update(*itr);
+    }
+    m_newNodes.clear();
+    m_modifiedNodes.clear();
+}
diff --git a/KREngine/KREngine/Classes/KRScene.h b/KREngine/KREngine/Classes/KRScene.h
index 2cf882d..051f537 100644
--- a/KREngine/KREngine/Classes/KRScene.h
+++ b/KREngine/KREngine/Classes/KRScene.h
@@ -42,6 +42,7 @@
 #import "KRCamera.h"
 #import "KRModelManager.h"
 #import "KRNode.h"
+#import "KROctree.h"
 class KRBoundingVolume;
 class KRInstance;
 class KRDirectionalLight;
@@ -69,6 +70,14 @@ public:
     
     KRBoundingVolume getExtents(KRContext *pContext);
     double sun_pitch, sun_yaw;
+    
+    void registerNotified(KRNotified *pNotified);
+    void unregisterNotified(KRNotified *pNotified);
+    
+    void notify_sceneGraphCreate(KRNode *pNode);
+    void notify_sceneGraphDelete(KRNode *pNode);
+    void notify_sceneGraphModify(KRNode *pNode);
+    
 private:
     KRContext *m_pContext;
     KRDirectionalLight *findFirstDirectionalLight(KRNode &node);
@@ -76,6 +85,14 @@ private:
     KRNode *m_pRootNode;
     KRBoundingVolume *m_pExtents;
     KRDirectionalLight *m_pFirstDirectionalLight;
+    
+    std::set<KRNotified *> m_notifiedObjects;
+    std::set<KRNode *> m_allNodes;
+    std::set<KRNode *> m_newNodes;
+    std::set<KRNode *> m_modifiedNodes;
+    
+    KROctree m_nodeTree;
+    void updateOctree();
 
 };
 
diff --git a/KREngine/KREngine/Classes/KRSkyBox.cpp b/KREngine/KREngine/Classes/KRSkyBox.cpp
index bbd5fb8..306d378 100644
--- a/KREngine/KREngine/Classes/KRSkyBox.cpp
+++ b/KREngine/KREngine/Classes/KRSkyBox.cpp
@@ -14,7 +14,7 @@
 #import "KRMat4.h"
 #import "KRResource.h"
 
-KRSkyBox::KRSkyBox(KRContext &context, std::string name) : KRNode(context, name)
+KRSkyBox::KRSkyBox(KRScene &scene, std::string name) : KRNode(scene, name)
 {
     m_frontTexture = "";
     m_backTexture = "";
diff --git a/KREngine/KREngine/Classes/KRSkyBox.h b/KREngine/KREngine/Classes/KRSkyBox.h
index 508348c..9bf0072 100644
--- a/KREngine/KREngine/Classes/KRSkyBox.h
+++ b/KREngine/KREngine/Classes/KRSkyBox.h
@@ -18,7 +18,7 @@ class KRSkyBox : public KRNode {
     
 public:
     
-    KRSkyBox(KRContext &context, std::string name);
+    KRSkyBox(KRScene &scene, std::string name);
     virtual ~KRSkyBox();
     
     virtual std::string getElementName();
diff --git a/KREngine/KREngine/Classes/KRSpotLight.cpp b/KREngine/KREngine/Classes/KRSpotLight.cpp
index 75d76f5..f937074 100644
--- a/KREngine/KREngine/Classes/KRSpotLight.cpp
+++ b/KREngine/KREngine/Classes/KRSpotLight.cpp
@@ -10,7 +10,7 @@
 
 #import "KRSpotLight.h"
 
-KRSpotLight::KRSpotLight(KRContext &context, std::string name) : KRLight(context, name)
+KRSpotLight::KRSpotLight(KRScene &scene, std::string name) : KRLight(scene, name)
 {
 }
 
diff --git a/KREngine/KREngine/Classes/KRSpotLight.h b/KREngine/KREngine/Classes/KRSpotLight.h
index c1eedef..02f2a9e 100644
--- a/KREngine/KREngine/Classes/KRSpotLight.h
+++ b/KREngine/KREngine/Classes/KRSpotLight.h
@@ -13,7 +13,7 @@
 
 class KRSpotLight : public KRLight {
 public:
-    KRSpotLight(KRContext &context, std::string name);
+    KRSpotLight(KRScene &scene, std::string name);
     virtual ~KRSpotLight();
     
     virtual std::string getElementName();
diff --git a/KREngine/KREngine/Classes/KRVector2.cpp b/KREngine/KREngine/Classes/KRVector2.cpp
index 3d24499..7d6926c 100644
--- a/KREngine/KREngine/Classes/KRVector2.cpp
+++ b/KREngine/KREngine/Classes/KRVector2.cpp
@@ -31,6 +31,14 @@ KRVector2::KRVector2(const KRVector2 &v) {
     y = v.y;
 }
 
+KRVector2 KRVector2::Min() {
+    return KRVector2(-std::numeric_limits<float>::max());
+}
+
+KRVector2 KRVector2::Max() {
+    return KRVector2(std::numeric_limits<float>::max());
+}
+
 KRVector2 KRVector2::Zero() {
     return KRVector2(0.0f);
 }
diff --git a/KREngine/KREngine/Classes/KRVector2.h b/KREngine/KREngine/Classes/KRVector2.h
index 5a9a674..420a928 100644
--- a/KREngine/KREngine/Classes/KRVector2.h
+++ b/KREngine/KREngine/Classes/KRVector2.h
@@ -73,7 +73,8 @@ public:
     static float Cross(const KRVector2 &v1, const KRVector2 &v2);
     
     static float Dot(const KRVector2 &v1, const KRVector2 &v2);
-    
+    static KRVector2 Min();
+    static KRVector2 Max();
     static KRVector2 Zero();
     static KRVector2 One();
     
diff --git a/KREngine/KREngine/Classes/KRVector3.cpp b/KREngine/KREngine/Classes/KRVector3.cpp
index df083d1..a6f5c64 100644
--- a/KREngine/KREngine/Classes/KRVector3.cpp
+++ b/KREngine/KREngine/Classes/KRVector3.cpp
@@ -32,6 +32,7 @@
 #include "KRVector3.h"
 
 #include <math.h>
+#include <limits.h>
 
 //default constructor
 KRVector3::KRVector3()
@@ -47,6 +48,14 @@ KRVector3::KRVector3(const KRVector3 &v) {
     z = v.z;
 }
 
+KRVector3 KRVector3::Min() {
+    return KRVector3(-std::numeric_limits<float>::max());
+}
+
+KRVector3 KRVector3::Max() {
+    return KRVector3(std::numeric_limits<float>::max());
+}
+
 KRVector3 KRVector3::Zero() {
     return KRVector3(0.0f, 0.0f, 0.0f);
 }
diff --git a/KREngine/KREngine/Classes/KRVector3.h b/KREngine/KREngine/Classes/KRVector3.h
index 4de6d93..3ece381 100644
--- a/KREngine/KREngine/Classes/KRVector3.h
+++ b/KREngine/KREngine/Classes/KRVector3.h
@@ -74,7 +74,8 @@ public:
     static KRVector3 Cross(const KRVector3 &v1, const KRVector3 &v2);
     
     static float Dot(const KRVector3 &v1, const KRVector3 &v2);
-    
+    static KRVector3 Min();
+    static KRVector3 Max();
     static KRVector3 Zero();
     static KRVector3 One();
     static KRVector3 Forward();