Octree Visualizer

Octree Visualizer is a real-time graphics application designed to construct, visualize, and optimize spatial partitioning structures using Qt and OpenGL.

This project demonstrates the transition from ImGui-based workflows to the industry-standard Qt framework, integrated directly with native OpenGL rendering within a Visual Studio environment. The core focus is on spatial optimization algorithms and culling techniques fundamental to game engine development.

📸 Preview

🚀 Key Features & Implementation Details

1. Spatial Partitioning & Optimization

• Linear Octree with Morton Codes (Z-Order Curve):
  • Instead of standard pointer-based linking, points are sorted using Morton Codes (interleaving bits of x, y, z coordinates).
  • This improves memory locality and cache coherence during tree construction and traversal.
• Bitwise Indexing:
  • Utilizes efficient bit manipulation (Magic Bits) to calculate child node indices, minimizing branching overhead.

2. Rendering Optimization

• View Frustum Culling:
  • Implements geometric intersection tests between the camera's view frustum (6 planes) and Octree node AABBs.
  • Pruning: Recursively stops tree traversal for nodes outside the view, significantly reducing the number of debug lines generated and rendered.
• Visual Debugging:
  • Real-time visualization of the Octree hierarchy.
  • Color-coded points to visualize sorting order.

3. Qt & OpenGL Integration

• Qt OpenGL Widget:
  • Embeds a native OpenGL rendering context within a QOpenGLWidget.
  • Handles mouse events (camera orbit, zoom) using Qt's event system.
• Visual Studio Workflow:
  • Developed using Visual Studio 2022 with the Qt VS Tools extension, simulating a professional engine development environment (distinct from Qt Creator).

🛠 Tech Stack

• Language: C++17
• IDE: Visual Studio 2022 (MSVC)
• GUI Framework: Qt 6.x
• Graphics API: OpenGL 4.5 Core Profile
• Shading Language: GLSL
• Math Library: Qt GUI Module (QVector3D, QMatrix4x4)

📝 Roadmap

The ultimate goal is to process massive particle simulations entirely on the GPU.

• Core: OpenGL Setup with Qt Integration
• Algorithm: Linear Octree Implementation (Morton Encoding)
• Optimization: Frustum Culling & AABB Intersection
• GPU Acceleration: Migrate Octree construction and traversal to Compute Shaders.
• Dynamic Updates: Implement efficient re-insertion logic for moving particles.
• Indirect Draw: Utilize glMultiDrawElementsIndirect to reduce draw call overhead.

📂 Installation & Build

1. Prerequisites:
   • Visual Studio 2019 or 2022
   • Qt 6.10.1 (Prebuilt binaries for MSVC 64-bit)
   • Qt Visual Studio Tools (VS Extension)
2. Setup:
   • Open OctreeVisualizer.sln in Visual Studio.
   • Navigate to Extensions > Qt VS Tools > Qt Versions and link your installed Qt path (e.g., C:\Qt\6.10.1\msvc2019_64).
3. Build:
   • Select Release or Debug configuration.
   • Build and run.

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Last Update: Jan 2026