terrible branch.

tests/planet.cpp

@@ -32,6 +32,7 @@ private:
     std::map<int, bool> keyStates;
     float deltaTime = 0.16f;
     bool orbitEquator = false;
+    bool collapsed;
     float rotationRadius = 2500;
     float angle = 0.0f;
     const float ω = (std::pow(M_PI, 2) / 30) / 10;
@@ -84,7 +85,7 @@ public:
 
     void renderUI(GLFWwindow* window) {
         handleCameraControls(window);
-        ImGui::Begin("Planet Simulation");
+        collapsed = ImGui::Begin("Planet Simulation");
         if (ImGui::BeginTable("MainLayout", 2, ImGuiTableFlags_Resizable | ImGuiTableFlags_BordersOuter)) {
             ImGui::TableSetupColumn("Controls", ImGuiTableColumnFlags_WidthStretch, 0.3f);
             ImGui::TableSetupColumn("Preview", ImGuiTableColumnFlags_WidthStretch, 0.7f);
@@ -289,8 +290,9 @@ public:
 
     void renderPreviewPanel() {
         ImGui::BeginChild("PreviewChild", ImVec2(0, 0), true, ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse);
-        
+        if (!collapsed) {
             livePreview();
+        }
         if (textureInitialized) {
             float aspect = (float)currentPreviewFrame.getWidth() / (float)currentPreviewFrame.getHeight();
             float availWidth = ImGui::GetContentRegionAvail().x;

tests/ptest.cpp

@@ -10,6 +10,7 @@
 
 #include "../util/noise/pnoise.cpp"
 #include "planet.cpp"
+#include "worldbox.cpp"
 #include "../util/basicdefines.hpp"
 
 void framebuffer_size_callback(GLFWwindow* window, int width, int height) {
@@ -80,6 +81,7 @@ int main() {
 
     planetSimUI planetApp;
     NoisePreviewState noiseState;
+    worldboxSimUI worldBox;
 
     if (noiseState.layers.empty()) {
         NoiseLayer defaultLayer;
@@ -101,6 +103,7 @@ int main() {
         ImGui::GetMainViewport();
         drawNoiseLab(noiseState);
         planetApp.renderUI(window);
+        worldBox.renderUI(window);
 
         ImGui::Begin("Integration Control");
         ImGui::Text("Bridge: Noise Lab -> Planet Sim");

tests/worldbox.cpp

@@ -0,0 +1,347 @@
+#ifndef WORLDBOX_CPP
+#define WORLDBOX_CPP
+
+#include "../util/sim/worldbox.hpp"
+#include "../util/grid/camera.hpp"
+
+#include "../imgui/imgui.h"
+#include "../imgui/backends/imgui_impl_glfw.h"
+#include "../imgui/backends/imgui_impl_opengl3.h"
+#include <GLFW/glfw3.h>
+
+class worldboxSimUI {
+private:
+    worldboxsim sim;
+    Camera cam;
+    
+    // UI and Render State
+    GLuint textu = 0;
+    std::mutex PreviewMutex;
+    bool updatePreview = false;
+    bool textureInitialized = false;
+    frame currentPreviewFrame;
+    
+    // Rendering Settings
+    int outWidth = 1024;
+    int outHeight = 1024;
+    int reflectCount = 2;
+    bool slowRender = false;
+    float lodDist = 1024.0f;
+    float lodDropoff = 0.05f;
+    float maxViewDistance = 4096.0f;
+    bool globalIllumination = false;
+    bool useLod = true;
+    float framerate = 60.0f;
+    
+    // Input/Time
+    std::map<int, bool> keyStates;
+    std::chrono::steady_clock::time_point lastFrameTime;
+    float deltaTime = 0.016f;
+    
+    // Stats tracking
+    std::chrono::steady_clock::time_point lastStatsUpdate;
+    std::string cachedStats;
+    bool statsNeedUpdate = true;
+
+    enum class DebugColorMode {
+        BASE,
+        NUTRIENTS,
+        MOISTURE
+    };
+    DebugColorMode currentColorMode = DebugColorMode::BASE;
+
+public:
+    worldboxSimUI() {
+        // Position camera to look at the center of the world slightly from above
+        cam.origin = v3(0, 50, 80);
+        v3 target = v3(0, 0, 0);
+        cam.direction = (target - cam.origin).normalized();
+        cam.up = v3(0, 1, 0);
+        cam.fov = 60;
+        cam.rotationSpeed = M_1_PI;
+        cam.movementSpeed = 50.0f;
+        lastFrameTime = std::chrono::steady_clock::now();
+    }
+
+    ~worldboxSimUI() {
+        if (textu != 0) {
+            glDeleteTextures(1, &textu);
+        }
+        sim.grid.clear();
+    }
+
+    void renderUI(GLFWwindow* window) {
+        // Compute delta time for consistent movement and sim stepping
+        auto now = std::chrono::steady_clock::now();
+        deltaTime = std::chrono::duration<float>(now - lastFrameTime).count();
+        lastFrameTime = now;
+
+        handleCameraControls(window);
+        
+        // Update simulation objects like the Star
+        sim.updateStar(deltaTime);
+        sim.updateWeatherAndPhysics(deltaTime);
+        
+        ImGui::Begin("WorldBox Simulation");
+        if (ImGui::BeginTable("MainLayout", 2, ImGuiTableFlags_Resizable | ImGuiTableFlags_BordersOuter)) {
+            ImGui::TableSetupColumn("Controls", ImGuiTableColumnFlags_WidthStretch, 0.3f);
+            ImGui::TableSetupColumn("Preview", ImGuiTableColumnFlags_WidthStretch, 0.7f);
+            ImGui::TableNextColumn();
+            renderControlsPanel();
+            ImGui::TableNextColumn();
+            renderPreviewPanel();
+            ImGui::EndTable();
+        }
+        ImGui::End();
+    }
+
+    void handleCameraControls(GLFWwindow* window) {
+        glfwPollEvents();
+        for (int i = GLFW_KEY_SPACE; i <= GLFW_KEY_LAST; i++) {
+            keyStates[i] = (glfwGetKey(window, i) == GLFW_PRESS);
+        }
+        
+        float currentSpeed = cam.movementSpeed * deltaTime;
+        if (keyStates[GLFW_KEY_LEFT_SHIFT]) currentSpeed *= 3.0f; // Sprint
+
+        if (keyStates[GLFW_KEY_W]) cam.moveForward(currentSpeed);
+        if (keyStates[GLFW_KEY_S]) cam.moveBackward(currentSpeed);
+        if (keyStates[GLFW_KEY_A]) cam.moveLeft(currentSpeed);
+        if (keyStates[GLFW_KEY_D]) cam.moveRight(currentSpeed);
+        if (keyStates[GLFW_KEY_E]) cam.moveUp(currentSpeed);
+        if (keyStates[GLFW_KEY_Q]) cam.moveDown(currentSpeed);
+        
+        if (keyStates[GLFW_KEY_LEFT]) cam.rotateYaw(cam.rotationSpeed * deltaTime);
+        if (keyStates[GLFW_KEY_RIGHT]) cam.rotateYaw(-cam.rotationSpeed * deltaTime);
+        if (keyStates[GLFW_KEY_UP]) cam.rotatePitch(cam.rotationSpeed * deltaTime);
+        if (keyStates[GLFW_KEY_DOWN]) cam.rotatePitch(-cam.rotationSpeed * deltaTime);
+    }
+
+    void renderControlsPanel() {
+        ImGui::BeginChild("ControlsScroll", ImVec2(0, 0), true);
+        
+        if (ImGui::CollapsingHeader("World Generation", ImGuiTreeNodeFlags_DefaultOpen)) {
+            ImGui::DragFloat("Width (X)", &sim.config.worldSizeX, 1.0f, 10.0f, 2000.0f);
+            ImGui::DragFloat("Length (Z)", &sim.config.worldSizeZ, 1.0f, 10.0f, 2000.0f);
+            ImGui::DragFloat("Depth (Y)", &sim.config.worldDepth, 1.0f, 1.0f, 500.0f);
+            ImGui::DragFloat("Voxel Size", &sim.config.voxelSize, 0.1f, 0.1f, 10.0f);
+            
+            ImGui::ColorEdit3("Dirt Base Color", sim.config.baseDirtColor.data());
+            
+            ImGui::Separator();
+            
+            if (ImGui::Button("Generate Flat World", ImVec2(-1, 40))) {
+                sim.generateFlatWorld();
+                // applyDebugColorMode();
+                statsNeedUpdate = true;
+            }
+            if (ImGui::Button("Clear World", ImVec2(-1, 30))) {
+                sim.clearWorld();
+                statsNeedUpdate = true;
+            }
+        }
+
+        if (ImGui::CollapsingHeader("Weather & Physics", ImGuiTreeNodeFlags_DefaultOpen)) {
+            ImGui::Checkbox("Enable Gravity (Terrain)", &sim.config.enableGravity);
+            ImGui::DragFloat3("Gravity", sim.config.gravity.data());
+            ImGui::DragFloat3("Wind", sim.config.wind.data());
+            ImGui::DragFloat("Physics Step (sec)", &sim.config.physicsStep, 0.01f, 0.01f, 1.0f);
+            
+            ImGui::Separator();
+            ImGui::Text("Clouds & Rain");
+            ImGui::DragInt("Cloud Count", &sim.config.cloudCount, 1, 0, 100);
+            ImGui::DragFloat("Cloud Height", &sim.config.cloudHeight, 5.0f, 10.0f, 1000.0f);
+            ImGui::DragFloat("Rain Spawn Rate", &sim.config.rainSpawnRate, 0.1f, 0.0f, 50.0f);
+            ImGui::ColorEdit3("Cloud Color", sim.config.cloudColor.data());
+            ImGui::ColorEdit3("Rain Color", sim.config.rainColor.data());
+            
+            if (ImGui::Button("Generate Clouds", ImVec2(-1, 40))) {
+                sim.generateClouds();
+                applyDebugColorMode();
+                statsNeedUpdate = true;
+            }
+            if (ImGui::Button("Clear Weather", ImVec2(-1, 30))) {
+                for (auto& c : sim.clouds) sim.grid.remove(c.pos);
+                for (auto& r : sim.rainDrops) sim.grid.remove(r.pos);
+                sim.clouds.clear();
+                sim.rainDrops.clear();
+                statsNeedUpdate = true;
+            }
+        }
+
+        if (ImGui::CollapsingHeader("Environment & Celestial", ImGuiTreeNodeFlags_DefaultOpen)) {
+            ImGui::Text("Star Settings");
+            ImGui::Checkbox("Enable Star Rotation", &sim.config.enableStarRotation);
+            ImGui::DragFloat("Orbit Radius", &sim.config.starOrbitRadius, 10.0f, 100.0f, 5000.0f);
+            ImGui::DragFloat("Star Speed", &sim.config.starSpeed, 0.01f, 0.0f, 5.0f);
+            ImGui::DragFloat("Panel Size", &sim.config.starPanelSize, 5.0f, 10.0f, 1000.0f);
+            ImGui::ColorEdit3("Star Color", sim.config.starColor.data());
+
+            ImGui::Separator();
+            ImGui::Text("Grass Settings");
+            ImGui::SliderFloat("Grass Density", &sim.config.grassDensity, 0.0f, 1.0f);
+            ImGui::ColorEdit3("Grass Color Base", sim.config.grassColorBase.data());
+            
+            if (ImGui::Button("Generate Grass", ImVec2(-1, 40))) {
+                sim.generateGrass();
+                applyDebugColorMode();
+                statsNeedUpdate = true;
+            }
+        }
+
+        if (ImGui::CollapsingHeader("Debug Views")) {
+            ImGui::Text("Render Data Mode:");
+            bool colorChanged = false;
+            if (ImGui::RadioButton("Base Color", currentColorMode == DebugColorMode::BASE)) { 
+                currentColorMode = DebugColorMode::BASE;
+                colorChanged = true;
+            }
+            if (ImGui::RadioButton("Nutrients", currentColorMode == DebugColorMode::NUTRIENTS)) { 
+                currentColorMode = DebugColorMode::NUTRIENTS;
+                colorChanged = true;
+            }
+            if (ImGui::RadioButton("Moisture", currentColorMode == DebugColorMode::MOISTURE)) { 
+                currentColorMode = DebugColorMode::MOISTURE;
+                colorChanged = true;
+            }
+
+            if (colorChanged) {
+                applyDebugColorMode();
+            }
+        }
+
+        if (ImGui::CollapsingHeader("Camera & Render Settings", ImGuiTreeNodeFlags_DefaultOpen)) {
+            ImGui::DragFloat3("Origin", cam.origin.data());
+            ImGui::DragFloat3("Direction", cam.direction.data(), 0.0001f, -1.0f, 1.0f);
+            ImGui::DragFloat("Movement Speed", &cam.movementSpeed, 0.1f, 1.0f, 500.0f);
+            ImGui::InputFloat("Max Framerate", &framerate, 1, 10);
+            
+            ImGui::Checkbox("Use PBR/Raytracing (Slow)", &slowRender);
+            if(slowRender) {
+                ImGui::DragInt("Bounces", &reflectCount, 1, 0, 10);
+                ImGui::Checkbox("Global Illumination", &globalIllumination);
+            }
+            
+            ImGui::Checkbox("Use LODs", &useLod);
+
+            if (ImGui::Button("Reset Camera")) {
+                cam.origin = v3(0, sim.config.worldDepth * 2.0f, std::max(sim.config.worldSizeX, sim.config.worldSizeZ));
+                cam.direction = (v3(0, 0, 0) - cam.origin).normalized();
+            }
+        }
+
+        updateStatsCache();
+        ImGui::TextUnformatted(cachedStats.c_str());
+
+        ImGui::EndChild();
+    }
+
+    void renderPreviewPanel() {
+        ImGui::BeginChild("PreviewChild", ImVec2(0, 0), true, ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse);
+        
+        livePreview();
+        if (textureInitialized) {
+            float aspect = (float)currentPreviewFrame.getWidth() / (float)currentPreviewFrame.getHeight();
+            float availWidth = ImGui::GetContentRegionAvail().x;
+            ImGui::Image((void*)(intptr_t)textu, ImVec2(availWidth, availWidth / aspect));
+        }
+
+        ImGui::EndChild();
+    }
+
+    void applyDebugColorMode() {
+        if (sim.grid.empty()) return;
+
+        v3 boundsHalfExtent = v3(sim.config.worldSizeX, sim.config.worldDepth, sim.config.worldSizeZ);
+        float searchRadius = boundsHalfExtent.norm() * 2.0f;
+
+        auto allNodes = sim.grid.findInRadius(v3(0,0,0), searchRadius);
+
+        for (auto& p : allNodes) {
+            if (!p || !p->active) continue;
+
+            v3 color = sim.config.baseDirtColor;
+            
+            switch (currentColorMode) {
+                case DebugColorMode::NUTRIENTS: {
+                    float t = std::clamp(p->data.nutrients, 0.0f, 1.0f);
+                    color = v3(1.0f - t, t, 0.0f);
+                    break;
+                }
+                case DebugColorMode::MOISTURE: {
+                    float t = std::clamp(p->data.moisture, 0.0f, 1.0f);
+                    color = v3(1.0f - t, 1.0f - t, 1.0f);
+                    break;
+                }
+                case DebugColorMode::BASE:
+                default:
+                    if (p->data.type == 0) {
+                        v3 darkDirt = sim.config.baseDirtColor * 0.4f;
+                        color = sim.config.baseDirtColor * (1.0f - p->data.moisture) + darkDirt * p->data.moisture;
+                    } else if (p->data.type == 1) {
+                        color = sim.config.baseRockColor;
+                    } else if (p->data.type == 2) {
+                        v3 lushGrass = sim.config.grassColorBase * 1.5f;
+                        color = sim.config.grassColorBase * (1.0f - p->data.moisture) + lushGrass * p->data.moisture;
+                    } else if (p->data.type == 3) {
+                        color = sim.config.starColor;
+                    } else if (p->data.type == 4) {
+                        color = sim.config.cloudColor;
+                    } else if (p->data.type == 5) {
+                        color = sim.config.rainColor;
+                    }
+                    break;
+            }
+
+            sim.grid.setColor(p->position, color);
+        }
+    }
+
+    void livePreview() {
+        std::lock_guard<std::mutex> lock(PreviewMutex);
+        updatePreview = true;
+        
+        float invFrameRate = 1.0f / framerate;
+        if (!useLod) {
+            sim.grid.setLODFalloff(0.01);
+            sim.grid.setLODMinDistance(1000.0f);
+        } else {
+            sim.grid.setLODMinDistance(lodDist);
+            sim.grid.setLODFalloff(lodDropoff);
+        }
+        sim.grid.setMaxDistance(maxViewDistance);
+        
+        if (slowRender) {
+            currentPreviewFrame = sim.grid.renderFrameTimed(cam, outHeight, outWidth, frame::colormap::RGB, invFrameRate, reflectCount, globalIllumination, useLod);
+        } else {
+            currentPreviewFrame = sim.grid.fastRenderFrame(cam, outHeight, outWidth, frame::colormap::RGB);
+        }
+        
+        if (textu == 0) {
+            glGenTextures(1, &textu);
+        }
+        glBindTexture(GL_TEXTURE_2D, textu);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+        
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, currentPreviewFrame.getWidth(), currentPreviewFrame.getHeight(), 
+                     0, GL_RGB, GL_UNSIGNED_BYTE, currentPreviewFrame.getData().data());
+        
+        updatePreview = false;
+        textureInitialized = true;
+    }
+
+    void updateStatsCache() {
+        auto now = std::chrono::steady_clock::now();
+        if (statsNeedUpdate || std::chrono::duration_cast<std::chrono::seconds>(now - lastStatsUpdate).count() >= 2) {
+            std::stringstream gridstats;
+            sim.grid.printStats(gridstats);
+            cachedStats = gridstats.str();
+            lastStatsUpdate = now;
+            statsNeedUpdate = false;
+        }
+    }
+};
+
+#endif

util/grid/grid3eigen.hpp

@@ -29,7 +29,7 @@
 
 constexpr int Dim = 3;
 
-template<typename T, typename IndexType = uint16_t>
+template<typename T, typename IndexType = uint32_t>
 class Octree {
 public:
     using PointType = Eigen::Matrix<float, Dim, 1>;
@@ -89,6 +89,13 @@ public:
         }
     };
 
+    struct RaycastHit {
+        std::shared_ptr<NodeData> node;
+        float distance;
+        PointType normal;
+        PointType hitPoint;
+    };
+
     struct OctreeNode {
         BoundingBox bounds;
         std::vector<std::shared_ptr<NodeData>> points;
@@ -235,7 +242,7 @@ private:
 
     float lodFalloffRate_ = 0.1f; // Lower = better, higher = worse. 0-1
     float lodMinDistance_ = 100.0f;
-    float maxDistance_ = size * size;
+    float maxDistance_ = 100000;
     
     struct Ray {
         PointType origin;
@@ -634,6 +641,89 @@ private:
         }
     }
 
+    void insertHit(std::vector<RaycastHit>& hits, size_t maxHits,  const std::shared_ptr<NodeData>& node, 
+                   float t, const PointType& normal, const PointType& hitPoint, float& maxDist) const {
+        for (const auto& h : hits) {
+            if (h.node == node) return;
+        }
+
+        auto it = std::lower_bound(hits.begin(), hits.end(), t, 
+            [](const RaycastHit& a, float val) {
+                return a.distance < val;
+            });
+            
+        hits.insert(it, {node, t, normal, hitPoint});
+        
+        if (hits.size() > maxHits) {
+            hits.pop_back();
+        }
+        
+        if (hits.size() == maxHits) {
+            maxDist = std::min(maxDist, hits.back().distance);
+        }
+    }
+
+    void voxelTraverseMultipleRecursive(OctreeNode* node, float tMin, float tMax, float& maxDist, bool enableLOD,
+                                        const Ray& ray, std::vector<RaycastHit>& hits, size_t maxHits, float invLodf) const {
+        if (enableLOD && !node->isLeaf) {
+            float dist = (node->center - ray.origin).norm();
+            float ratio = dist / node->nodeSize;
+            
+            if (dist > lodMinDistance_ && ratio > invLodf && node->lodData) {
+                float t;
+                PointType n;
+                PointType h;
+                if (rayCubeIntersect(ray, node->lodData.get(), t, n, h)) {
+                    if (t >= 0 && t <= maxDist) {
+                        insertHit(hits, maxHits, node->lodData, t, n, h, maxDist);
+                    }
+                }
+                return;
+            }
+        }
+
+        for (const auto& pointData : node->points) {
+            if (!pointData->active) continue;
+            
+            float t;
+            PointType normal, hitPoint;
+            if (rayCubeIntersect(ray, pointData.get(), t, normal, hitPoint)) {
+                if (t >= 0 && t <= maxDist && t <= tMax + 0.001f) {
+                    insertHit(hits, maxHits, pointData, t, normal, hitPoint, maxDist);
+                }
+            }
+        }
+
+        if (node->isLeaf) return;
+
+        // DDA Traversal
+        PointType center = node->center;
+        Eigen::Vector3f ttt = (center - ray.origin).cwiseProduct(ray.invDir);
+
+        int currIdx = 0;
+        currIdx = ((tMin >= ttt.x()) ? 1 : 0) | ((tMin >= ttt.y()) ? 2 : 0) | ((tMin >= ttt.z()) ? 4 : 0);
+        
+        float tNext;
+
+        while(tMin < tMax && tMin <= maxDist) {
+            Eigen::Vector3f next_t;
+            next_t[0] = (currIdx & 1) ? tMax : ttt[0];
+            next_t[1] = (currIdx & 2) ? tMax : ttt[1];
+            next_t[2] = (currIdx & 4) ? tMax : ttt[2];
+
+            tNext = next_t.minCoeff();
+
+            int physIdx = currIdx ^ ray.signMask;
+
+            if (node->children[physIdx]) {
+                voxelTraverseMultipleRecursive(node->children[physIdx].get(), tMin, tNext, maxDist, enableLOD, ray, hits, maxHits, invLodf);
+            }
+
+            tMin = tNext;
+            currIdx |= ((next_t[0] <= tNext) ? 1 : 0) | ((next_t[1] <= tNext) ? 2 : 0) | ((next_t[2] <= tNext) ? 4 : 0);
+        }
+    }
+
     PointType sampleGGX(const PointType& n, float roughness, uint32_t& state) const {
         float alpha = std::max(EPSILON, roughness * roughness);
         float r1 = float(rand_r(&state)) / float(RAND_MAX);
@@ -2280,6 +2370,11 @@ public:
         
         size = 0;
     }
+
+    void collectNodesByObjectId(int id, std::vector<std::shared_ptr<NodeData>>& results) const {
+        std::unordered_set<std::shared_ptr<NodeData>> seen;
+        collectNodesByObjectIdRecursive(root_.get(), id, results, seen);
+    }
 };
 
 #endif

util/noise/pnoise.cpp

@@ -189,8 +189,7 @@ inline void updateNoiseTexture(NoisePreviewState& state) {
 
     glBindTexture(GL_TEXTURE_2D, state.textureId);
     glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
-    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, state.width, state.height, 
-                 0, GL_RGB, GL_UNSIGNED_BYTE, state.pixelBuffer.data());
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, state.width, state.height, 0, GL_RGB, GL_UNSIGNED_BYTE, state.pixelBuffer.data());
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
     

util/sim/planet.hpp

@@ -837,6 +837,57 @@ public:
 
     void addMoon() {
         ///TODO: using planetConfig, add moon(s).
+        TIME_FUNCTION;
+
+        const float realEarthRadiusKm = 6371.0f;
+        const float realMoonRadiusKm = 1737.4f;
+        const float realOrbitKm = 384400.0f;
+        float simScale = config.radius / realEarthRadiusKm;
+
+        float moonRadius = realMoonRadiusKm * simScale;
+        float orbitDistance = realOrbitKm * simScale;
+
+        std::cout << "--- MOON GENERATION ---" << std::endl;
+        std::cout << "Sim Scale: " << simScale << " units/km" << std::endl;
+        std::cout << "Moon Radius: " << moonRadius << " units" << std::endl;
+        std::cout << "Orbit Distance: " << orbitDistance << " units" << std::endl;
+
+        // Place the moon on the Z-axis to keep it distinct from the star (which is on the X-axis)
+        v3 moonCenter = config.center + v3(0.0f, 0.0f, orbitDistance);
+        v3 moonColor = v3(0.7f, 0.7f, 0.72f); // Pale gray color
+
+        // Surface area ratio Moon/Earth is ~0.074. We scale the points to maintain node density.
+        int moonPoints = std::max(1000, static_cast<int>(config.surfacePoints * 0.075f));
+
+        for (int i = 0; i < moonPoints; i++) {
+            float y = 1.0f - (i * 2.0f) / (moonPoints - 1);
+            float radiusY = std::sqrt(1.0f - y * y);
+            float Θ = Φ * i;
+            float x = std::cos(Θ) * radiusY;
+            float z = std::sin(Θ) * radiusY;
+
+            v3 dir(x, y, z);
+            v3 pos = moonCenter + dir * moonRadius;
+            Particle pt;
+            
+            pt.altPos = std::make_unique<AltPositions>();
+            pt.altPos->originalPos = pos.cast<Eigen::half>();
+            pt.altPos->noisePos = pos.cast<Eigen::half>();
+            pt.altPos->tectonicPos = pos.cast<Eigen::half>();
+            
+            pt.currentPos = pos;
+            pt.originColor = moonColor.cast<Eigen::half>();
+            pt.noiseDisplacement = 0.0f;
+            pt.surface = true;
+            
+            config.surfaceNodes.emplace_back(pt);
+            
+            grid.set(pt, pt.currentPos, true, pt.originColor.cast<float>(), config.voxelSize, true, 3, 0, 1.0, 0.0f, 0.0f, 1.0f);
+        }
+        
+        grid.optimize();
+        std::cout << "Moon generation complete. Placed " << moonPoints << " nodes." << std::endl;
+        starAdded = true;
     }
     
     void stretchPlanet() {

util/sim/worldbox.hpp

@@ -0,0 +1,421 @@
+#ifndef WORLDBOX_HPP
+#define WORLDBOX_HPP
+
+#include <iostream>
+#include <vector>
+#include <chrono>
+#include <thread>
+#include <mutex>
+#include <cmath>
+#include <random>
+#include <algorithm>
+
+#include "../grid/grid3eigen.hpp"
+#include "../timing_decorator.cpp"
+
+using v3 = Eigen::Vector3f;
+
+struct WorldVoxel {
+    float nutrients = 1.0f;
+    float moisture = 0.5f;
+    int type = 0; // 0=Dirt, 1=Rock, 2=Grass, 3=Star, 4=Cloud, 5=Rain
+
+    WorldVoxel() = default;
+    
+    WorldVoxel(float nut, float mois, int t) : nutrients(nut), moisture(mois), type(t) {}
+};
+
+struct WorldBoxConfig {
+    v3 center = v3(0, 0, 0);
+    float worldSizeX = 1000.0f;
+    float worldSizeZ = 1000.0f;
+    float worldDepth = 20.0f;
+    
+    float voxelSize = 2.0f;
+    v3 baseDirtColor = v3(0.36f, 0.25f, 0.14f);
+    v3 baseRockColor = v3(0.45f, 0.45f, 0.45f);
+    
+    float gridSizeCubeMin = 1024.0f;
+
+    // Grass Config
+    float grassDensity = 0.05f;
+    v3 grassColorBase = v3(0.2f, 0.6f, 0.15f);
+
+    // Star Config
+    bool enableStarRotation = false; // Off by default
+    float starOrbitRadius = 800.0f;
+    float starPanelSize = 100.0f;
+    float starVoxelSize = 10.0f;
+    v3 starColor = v3(1.0f, 0.95f, 0.8f);
+    float starSpeed = 0.2f; // Radians per second
+    float starAngle = 0.0f; 
+
+    // Weather Config
+    int cloudCount = 15;
+    float cloudHeight = 150.0f;
+    v3 cloudColor = v3(0.9f, 0.9f, 0.95f);
+    float cloudBaseSize = 6.0f;
+
+    v3 rainColor = v3(0.2f, 0.4f, 0.9f);
+    float rainDropSize = 0.5f;
+    float rainSpawnRate = 1.0f;
+
+    // Physics Config
+    bool enableGravity = true;
+    v3 gravity = v3(0.0f, -60.0f, 0.0f);
+    v3 wind = v3(20.0f, 0.0f, 10.0f);
+    float physicsStep = 0.1f;
+};
+
+struct CloudVoxel {
+    v3 pos;
+    float size;
+};
+
+struct RainDrop {
+    v3 pos;
+    v3 vel;
+};
+
+class worldboxsim {
+public:
+    WorldBoxConfig config;
+    Octree<WorldVoxel> grid;
+    std::mt19937 rng;
+    std::vector<v3> starVoxelPositions;
+    
+    std::vector<CloudVoxel> clouds;
+    std::vector<RainDrop> rainDrops;
+    float physicsTimer = 0.0f;
+
+    worldboxsim() : rng(42) {
+        config = WorldBoxConfig();
+        grid = Octree<WorldVoxel>(v3(-config.gridSizeCubeMin, -config.gridSizeCubeMin, -config.gridSizeCubeMin),v3(config.gridSizeCubeMin,  config.gridSizeCubeMin,  config.gridSizeCubeMin), 16, 32);
+        grid.setBackgroundColor(v3(0.53f, 0.81f, 0.92f));
+    }
+
+    void updateStar(float dt) {
+        if (!config.enableStarRotation) {
+            if (!starVoxelPositions.empty()) {
+                for(const auto& pos : starVoxelPositions) {
+                    grid.remove(pos); 
+                }
+                starVoxelPositions.clear();
+            }
+            return;
+        }
+
+        // Calculate rotation
+        config.starAngle += dt * config.starSpeed;
+        if (config.starAngle > 2 * M_PI) config.starAngle -= 2 * M_PI;
+
+        // Calculate new center of star (orbiting on the X/Y plane)
+        v3 starCenter(cos(config.starAngle) * config.starOrbitRadius, sin(config.starAngle) * config.starOrbitRadius, 0.0f);
+
+        // Create a flat panel facing the origin
+        v3 n = -starCenter.normalized();
+        v3 worldUp(0, 1, 0);
+        if (std::abs(n.dot(worldUp)) > 0.99f) worldUp = v3(0, 0, 1);
+        v3 right = worldUp.cross(n).normalized();
+        v3 up = n.cross(right).normalized();
+
+        int halfGrid = std::max(1, static_cast<int>((config.starPanelSize / config.starVoxelSize) / 2.0f));
+        WorldVoxel starVoxel(0.0f, 0.0f, 3); // Type 3 = Star
+        
+        // Calculate the new ideal positions for this frame
+        std::vector<v3> newPositions;
+        newPositions.reserve((2 * halfGrid + 1) * (2 * halfGrid + 1));
+
+        for (int i = -halfGrid; i <= halfGrid; ++i) {
+            for (int j = -halfGrid; j <= halfGrid; ++j) {
+                newPositions.push_back(starCenter + (right * (i * config.starVoxelSize)) + (up * (j * config.starVoxelSize)));
+            }
+        }
+
+        // Apply grid changes
+        if (starVoxelPositions.empty()) {
+            // Creation: Spawn voxels into the grid for the first time
+            for (const auto& pos : newPositions) {
+                // Injecting a high emittance factor (15.0f) to make it a bright emissive light source
+                grid.set(starVoxel, pos, true, config.starColor, config.starVoxelSize, true, 1, 1, 15.0f);
+            }
+            starVoxelPositions = newPositions;
+        } else if (starVoxelPositions.size() == newPositions.size()) {
+            // Moving: Using grid.move() to smoothly transfer nodes in the Octree
+            for (size_t i = 0; i < starVoxelPositions.size(); ++i) {
+                grid.move(starVoxelPositions[i], newPositions[i]);
+            }
+            starVoxelPositions = newPositions;
+        } 
+    }
+
+    void generateClouds() {
+        std::uniform_real_distribution<float> randX(-config.worldSizeX/2, config.worldSizeX/2);
+        std::uniform_real_distribution<float> randZ(-config.worldSizeZ/2, config.worldSizeZ/2);
+        std::uniform_real_distribution<float> randY(config.cloudHeight - 10.0f, config.cloudHeight + 10.0f);
+
+        for (int i=0; i<config.cloudCount; ++i) {
+            v3 center(randX(rng), randY(rng), randZ(rng));
+            int numVoxels = 10 + (rng() % 20);
+            
+            for (int j=0; j<numVoxels; ++j) {
+                v3 offset(
+                    (rng() % 40) - 20,
+                    (rng() % 10) - 5,
+                    (rng() % 40) - 20
+                );
+                v3 pos = center + offset;
+                float size = config.cloudBaseSize + (rng() % 6);
+                
+                WorldVoxel vox(0.0f, 1.0f, 4); // Type 4 = Cloud
+                // Adding to grid with transmission=0.4f (makes it partially transparent for RTX)
+                grid.set(vox, pos, true, config.cloudColor, size, true, 4, 0, 0.0f, 1.0f, 0.0f, 0.4f);
+                clouds.push_back({pos, size});
+            }
+        }
+    }
+
+    void updateWeatherAndPhysics(float dt) {
+        float halfX = config.worldSizeX / 2.0f;
+        float halfZ = config.worldSizeZ / 2.0f;
+
+        // 1. Clouds Update
+        std::vector<CloudVoxel> nextClouds;
+        for (auto& c : clouds) {
+            v3 nextPos = c.pos + config.wind * dt;
+            
+            // Screen wrap logic for wind drift
+            if (nextPos.x() > halfX) nextPos.x() -= config.worldSizeX;
+            if (nextPos.x() < -halfX) nextPos.x() += config.worldSizeX;
+            if (nextPos.z() > halfZ) nextPos.z() -= config.worldSizeZ;
+            if (nextPos.z() < -halfZ) nextPos.z() += config.worldSizeZ;
+            
+            if (grid.move(c.pos, nextPos)) {
+                c.pos = nextPos;
+            } else {
+                WorldVoxel vox(0.0f, 1.0f, 4);
+                grid.set(vox, nextPos, true, config.cloudColor, c.size, true, 4, 0, 0.0f, 1.0f, 0.0f, 0.4f);
+                c.pos = nextPos;
+            }
+            nextClouds.push_back(c);
+            
+            // Spawn Rain
+            std::uniform_real_distribution<float> dist(0, 1);
+            if (dist(rng) < (config.rainSpawnRate * dt * 0.1f)) {
+                RainDrop r = {c.pos - v3(0, c.size, 0), config.wind};
+                rainDrops.push_back(r);
+                WorldVoxel rv(0.0f, 1.0f, 5); // Type 5 = Rain
+                grid.set(rv, r.pos, true, config.rainColor, config.rainDropSize, true, 5);
+            }
+        }
+        clouds = nextClouds;
+        
+        // 2. Rain Update
+        std::vector<RainDrop> nextRain;
+        for (auto& r : rainDrops) {
+            r.vel += config.gravity * dt;
+            v3 nextPos = r.pos + r.vel * dt;
+            
+            v3 dir = (nextPos - r.pos);
+            float distMag = dir.norm();
+            
+            if (distMag > 0) {
+                dir.normalize();
+                auto hit = grid.voxelTraverse(r.pos, dir, distMag, false);
+                
+                // If it hits solid terrain
+                if (hit && hit->data.type != 4 && hit->data.type != 5) {
+                    if (hit->data.type == 0) { // Hit Dirt
+                        hit->data.moisture = std::min(1.0f, hit->data.moisture + 0.15f);
+                        v3 darkDirt = config.baseDirtColor * 0.4f;
+                        v3 wetColor = config.baseDirtColor * (1.0f - hit->data.moisture) + darkDirt * hit->data.moisture;
+                        grid.setColor(hit->position, wetColor);
+                    } else if (hit->data.type == 2) { // Hit Grass
+                        hit->data.moisture = std::min(1.0f, hit->data.moisture + 0.15f);
+                        v3 lushGrass = config.grassColorBase * 1.5f;
+                        v3 wetColor = config.grassColorBase * (1.0f - hit->data.moisture) + lushGrass * hit->data.moisture;
+                        grid.setColor(hit->position, wetColor);
+                    }
+                    
+                    grid.remove(r.pos);
+                    continue; 
+                }
+            }
+            
+            // Delete if falls out of bounds
+            if (nextPos.y() < -config.worldDepth - 20.0f) {
+                grid.remove(r.pos);
+                continue;
+            }
+            
+            if (grid.move(r.pos, nextPos)) {
+                r.pos = nextPos;
+                nextRain.push_back(r);
+            } else {
+                WorldVoxel rv(0.0f, 1.0f, 5);
+                grid.set(rv, nextPos, true, config.rainColor, config.rainDropSize, true, 5);
+                r.pos = nextPos;
+                nextRain.push_back(r);
+            }
+        }
+        rainDrops = nextRain;
+        
+        // 3. Apply Block Gravity
+        if (config.enableGravity) {
+            physicsTimer += dt;
+            if (physicsTimer >= config.physicsStep) {
+                applyTerrainGravity();
+                physicsTimer = 0.0f;
+            }
+        }
+    }
+
+    void applyTerrainGravity() {
+        std::vector<std::shared_ptr<Octree<WorldVoxel>::NodeData>> nodes;
+        grid.collectNodesByObjectId( -1, nodes);
+        
+        std::vector<std::shared_ptr<Octree<WorldVoxel>::NodeData>> terrain;
+        terrain.reserve(nodes.size());
+        for (auto& n : nodes) {
+            // Include Dirt, Rock, and Grass in gravity sweep
+            if (n->data.type == 0 || n->data.type == 1 || n->data.type == 2) {
+                terrain.push_back(n);
+            }
+        }
+        
+        // Process Bottom-Up
+        std::sort(terrain.begin(), terrain.end(), [](const auto& a, const auto& b) {
+            return a->position.y() < b->position.y();
+        });
+        
+        for (auto& n : terrain) {
+            v3 belowPos = n->position + v3(0, -config.voxelSize, 0);
+            
+            // Bounds check so voxels don't fall infinitely
+            if (belowPos.y() < -config.worldDepth) continue;
+            
+            auto hit = grid.find(belowPos, config.voxelSize * 0.1f);
+            if (!hit) {
+                grid.move(n->position, belowPos);
+            }
+        }
+    }
+
+    void generateGrass() {
+        TIME_FUNCTION;
+        float halfX = config.worldSizeX / 2.0f;
+        float halfZ = config.worldSizeZ / 2.0f;
+        float surfaceY = 0.0f; 
+
+        int stepsX = static_cast<int>(std::round(config.worldSizeX / config.voxelSize)) + 1;
+        int stepsZ = static_cast<int>(std::round(config.worldSizeZ / config.voxelSize)) + 1;
+
+        int grassCount = 0;
+
+        #pragma omp parallel
+        {
+            std::random_device rd;
+            std::mt19937 local_rng(rd() ^ std::hash<std::thread::id>()(std::this_thread::get_id()));
+            std::uniform_real_distribution<float> probDist(0.0f, 1.0f);
+            std::uniform_int_distribution<int> grassHeightDist(1, 8);
+
+            #pragma omp for schedule(static) collapse(2)
+            for (int i = 0; i < stepsX; ++i) {
+                for (int j = 0; j < stepsZ; ++j) {
+                    
+                    float x = -halfX + i * config.voxelSize;
+                    float z = -halfZ + j * config.voxelSize;
+
+                    if (x > halfX || z > halfZ) continue;
+                    
+                    if (probDist(local_rng) < config.grassDensity) {
+                        int gHeight = grassHeightDist(local_rng);
+                        float gSize = config.voxelSize / 25.0f;
+                        
+                        std::uniform_real_distribution<float> offDist(-config.voxelSize/2.0f + gSize/2.0f, config.voxelSize/2.0f - gSize/2.0f);
+                        float offsetX = offDist(local_rng);
+                        float offsetZ = offDist(local_rng);
+                        
+                        WorldVoxel gVox(1.0f, 0.8f, 2); // Type 2 = Grass
+                        float baseY = surfaceY + (config.voxelSize / 2.0f) + (gSize / 2.0f);
+                        
+                        #pragma omp critical
+                        {
+                            for (int g = 0; g < gHeight; ++g) {
+                                v3 gPos(x + offsetX, baseY + g * gSize, z + offsetZ);
+                                grid.set(gVox, gPos, true, config.grassColorBase, gSize, true, 1, 0);
+                                grassCount++;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        std::cout << "Grass generation complete. Placed " << grassCount << " grass voxels." << std::endl;
+    }
+
+    void generateFlatWorld() {
+        TIME_FUNCTION;
+        grid.clear();
+        
+        float halfX = config.worldSizeX / 2.0f;
+        float halfZ = config.worldSizeZ / 2.0f;
+        float surfaceY = 0.0f; 
+
+        // 1. Calculate integer bounds to satisfy OpenMP
+        int stepsX = static_cast<int>(std::round(config.worldSizeX / config.voxelSize)) + 1;
+        int stepsZ = static_cast<int>(std::round(config.worldSizeZ / config.voxelSize)) + 1;
+        int stepsY = static_cast<int>(std::round(config.worldDepth / config.voxelSize)) + 1;
+        size_t maxSteps = stepsX * stepsZ * stepsY;
+
+        int nodeCount = 0;
+
+        #pragma omp parallel for schedule(static) collapse(3)
+        for (int i = 0; i < stepsX; ++i) {
+            for (int j = 0; j < stepsZ; ++j) {
+                for (int k = 0; k < stepsY; ++k) {
+                    
+                    float x = -halfX + i * config.voxelSize;
+                    float z = -halfZ + j * config.voxelSize;
+                    float y = surfaceY - k * config.voxelSize;
+
+                    if (x > halfX || z > halfZ || y < surfaceY - config.worldDepth) {
+                        continue;
+                    }
+                    
+                    WorldVoxel voxel;
+                    v3 color;
+                    
+                    float depthRatio = std::abs(y - surfaceY) / config.worldDepth;
+                    
+                    if (depthRatio > 0.8f) {
+                        voxel.type = 1;
+                        voxel.nutrients = 0.1f;
+                        color = config.baseRockColor;
+                    } else {
+                        voxel.type = 0;
+                        voxel.nutrients = 1.0f - depthRatio;
+                        color = config.baseDirtColor;
+                    }
+
+                    v3 pos(x, y, z);
+                
+                    #pragma omp critical
+                    grid.set(voxel, pos, true, color, config.voxelSize, true, 1, 0);
+                    // nodeCount++;
+                }
+            }
+        }
+        
+        std::cout << "World generation complete. Placed " << nodeCount << " voxels." << std::endl;
+    }
+
+    void clearWorld() {
+        grid.clear();
+        clouds.clear();
+        rainDrops.clear();
+        starVoxelPositions.clear();
+    }
+};
+
+#endif