usually works. need to figure out what causes it to not to sometimes.

tests/g3etest.cpp

@@ -0,0 +1,92 @@
+#include <iostream>
+#include <vector>
+#include <chrono>
+#include <thread>
+#include <atomic>
+#include <mutex>
+#include <cmath>
+
+#include "../util/grid/grid3eigen.hpp"
+#include "../util/output/bmpwriter.hpp"
+#include "../util/output/frame.hpp"
+#include "../util/timing_decorator.cpp"
+#include "../util/noise/pnoise2.hpp"
+#include "../util/output/aviwriter.hpp"
+
+#include "../imgui/imgui.h"
+#include "../imgui/backends/imgui_impl_glfw.h"
+#include "../imgui/backends/imgui_impl_opengl3.h"
+#include <GLFW/glfw3.h>
+#include "../stb/stb_image.h"
+
+int main() {
+    // Define octree boundaries (world space)
+    using PointType = Eigen::Matrix<float, 3, 1>;
+    PointType minBound(-2.0f, -2.0f, -2.0f);
+    PointType maxBound(2.0f, 2.0f, 2.0f);
+    
+    // Create octree
+    Octree<int> octree(minBound, maxBound, 16, 8); // max 16 points per node, max depth 8
+    
+    // Create green sphere (center at origin, radius 1.0)
+    float radius = 1.0f;
+    int pointCount = 0;
+    Eigen::Vector3f greenColor(0.0f, 1.0f, 0.0f); // green
+    
+    // Add points on sphere surface (simplified representation)
+    for (int i = 0; i < 1000; ++i) {
+        // Spherical coordinates
+        float u = static_cast<float>(rand()) / RAND_MAX;
+        float v = static_cast<float>(rand()) / RAND_MAX;
+        
+        // Convert to spherical coordinates
+        float theta = 2.0f * M_PI * u;  // azimuth
+        float phi = acos(2.0f * v - 1.0f);  // polar
+        
+        // Convert to Cartesian coordinates
+        float x = radius * sin(phi) * cos(theta);
+        float y = radius * sin(phi) * sin(theta);
+        float z = radius * cos(phi);
+        
+        PointType pos(x, y, z);
+        
+        // Set point data with larger size for visibility
+        // Note: The third parameter is size, which should be radius squared for intersection test
+        octree.set(i, pos, greenColor, 1.f, true);
+        pointCount++;
+    }
+    
+    std::cout << "Added " << pointCount << " points to the green sphere." << std::endl;
+    
+    // Set camera parameters
+    PointType cameraPos(0.0f, 0.0f, 5.0f); // camera position
+    PointType lookDir(0.0f, 0.0f, -1.0f);  // looking at sphere
+    PointType upDir(0.0f, 1.0f, 0.0f);     // up direction
+    PointType rightDir(1.0f, 0.0f, 0.0f);  // right direction
+    
+    // Render parameters
+    int width = 800;
+    int height = 600;
+    
+    std::cout << "Rendering frame..." << std::endl;
+    
+    // Render frame
+    frame renderedFrame = octree.renderFrame(cameraPos, lookDir, upDir, rightDir, height, width, frame::colormap::RGB);
+    
+    std::cout << "Frame rendered. Dimensions: " 
+              << renderedFrame.getWidth() << "x" 
+              << renderedFrame.getHeight() << std::endl;
+    
+    // Save as BMP
+    std::string filename = "output/green_sphere.bmp";
+    std::cout << "Saving to " << filename << "..." << std::endl;
+    
+    if (BMPWriter::saveBMP(filename, renderedFrame)) {
+        std::cout << "Successfully saved green sphere to " << filename << std::endl;
+    } else {
+        std::cerr << "Failed to save BMP file!" << std::endl;
+        return 1;
+    }
+    
+    return 0;
+}