🌍 3D Orbit System

A realistic solar system simulation with Earth, Moon, and Sun orbiting in 3D space !

🎮 Overview

An interactive 3D visualization of a solar system where you can freely navigate and observe celestial bodies in motion with realistic lighting and dynamic effects.

> Scene Description:

A cosmic environment featuring the Sun at the center, Earth orbiting around it while rotating on its axis, and the Moon circling Earth. The background contains 1000 twinkling stars creating a stellar atmosphere, with 30 falling stars streaking across space. Dynamic dual-lighting system from both the Sun and Moon illuminates the scene realistically.

> Navigation:

1. Move freely in 3D space with WASD and arrow keys
2. Rotate camera with LEFT/RIGHT arrows
3. Zoom in/out to observe planets in detail
4. Control time to speed up or slow down orbital motion
5. Watch realistic planetary rotations and orbital mechanics

> Key Controls:

WASD          : Move Forward/Backward/Left/Right
UP/DOWN       : Move Up/Down
LEFT/RIGHT    : Look Left/Right
Z / X         : Zoom In/Out
+ / -         : Speed Up/Slow Down Time (0.1x to 5x)
R             : Reset Time to Normal Speed
ESC           : Exit

🛠️ Implemented Technical Features

• Free camera movement with full 3D navigation
• Hierarchical transformations for orbital mechanics (Earth around Sun, Moon around Earth)
• Phong lighting model with ambient, diffuse, and specular
• Dual light sources (Sun as primary, Moon as secondary)
• Dynamic textures on all celestial bodies
• Particle systems for background and falling stars
• Time control for animation speed

> Technologies Used:

• C++17 with procedural programming
• OpenGL 3.3+ (Core Profile) for 3D rendering
• GLFW for window management and inputs
• GLAD as OpenGL loader
• GLM for 3D mathematics
• STB Image for texture loading
• CMake for build system
• MinGW-w64 as Windows compiler

> Shader Structure:

• Vertex Shader: MVP transformations + normal calculations + texture coords
• Fragment Shader: Phong lighting + multi-texture support + dual light sources + star effects

> 3D Models:

• Procedural spheres for Sun, Earth, Moon (parametric generation)
• OBJ loader for falling stars (comet.obj)
• Efficient mesh system with VAO/VBO/EBO

> Used Textures:

• earth.jpg - Earth surface map
• sun.jpg - Solar surface texture
• moon.jpg - Lunar surface detail
• Loaded via STB Image with automatic mipmap generation

🎬 ANIMATION:

1. Celestial Bodies

• Sun: Slow axial rotation
• Earth: Rotation on axis + orbit around Sun
• Moon: Rotation on axis + orbit around Earth
• Frame-independent timing for smooth animation

2. Falling Stars

• 30 falling stars with left-to-right comet trajectory
• High speed (15-30 units) without rotation
• Red-blue color palette (red/blue/purple variants)
• Respawn system when exiting boundaries

3. Background Stars

• 1000 stars in spherical distribution
• Twinkling effect with brightness variation
• Point sprite rendering for circular shapes

💡 LIGHTING (Phong Model):

1. Ambient Light

• Global illumination at base intensity (0.2)
• Uniform distribution across all objects

2. Diffuse Light

• Sun light source: White light (1.0, 1.0, 1.0) from origin
• Moon light source: Weak blue-ish light (0.03) from Moon position
• Normal-based calculation: max(dot(normal, lightDir), 0.0)

3. Specular Light

• Reflections on surfaces with Phong model
• Material shininess:
  • Earth: 32.0 (moderate)
  • Sun: 16.0 (self-illuminated, 10x brightness boost)
  • Moon: 8.0 (rough surface)
• View direction calculation for accurate highlights

4. Dual Light System

• Primary source: Sun at origin with full white light
• Secondary source: Moon with weak reflected light
• Combined contribution in fragment shader
• Dynamic moon position following orbital calculations

📊 Important Technical Points

> Performance:

• Optimized VAO/VBO usage with minimal state changes
• Index buffers (EBO) for sphere geometry
• Depth testing enabled for proper rendering
• Efficient draw calls for all objects

> Extensibility:

• Modular CelestialBody struct for easy planet addition
• Configurable orbital parameters (radius, speed, size)
• Shader-based rendering for easy effect additions

> Current Limitations:

• Simplified physics (no real gravitational simulation)
• Fixed orbital planes (no inclination)
• Limited to 3 celestial bodies
• No collision detection

🔮 Possible Future Improvements

1. Additional planets (Mars, Jupiter, Saturn with rings)
2. Realistic gravitational physics (N-body simulation)
3. Planetary atmospheres with volumetric effects
4. Shadow mapping between celestial bodies
5. Orbit trail visualization
6. Information overlay with real-time data
7. Screenshot capture functionality

🚀 How to Run the Project

> Requirements:

• Windows 10/11 (tested on MinGW-w64)
• CMake 3.15+
• OpenGL 3.3+ compatible GPU

> Quick Start:

# 1. Clone/Download the project
git clone [https://github.com/Hanaa-22/3D-Orbit-System]

# 2. Navigate to project
cd tp

# 3. Compile and Launch
build_run.bat

# 4. Simulation window opens HEY HEY HEY !!

📁 Project Structure and Libraries

3D-OrbitSystem/
├── .gitignore
├── README.md                    
├── tp/ 
│   ├── (build folder)                 
│   ├── main.cpp                 # Main entry point
│   ├── objload.cpp/.hpp         # OBJ model loader
│   ├── CMakeLists.txt           # Build configuration
│   └── build_run.bat            # Automatic build script
│
└── libs/                        
    ├── glad/                    # OpenGL Loader
    ├── GLFW/                    # Window management
    ├── glm-1.0.2/               # 3D mathematics
    ├── mingw64/                 # MinGW compiler
    ├── shader/                  
    │   ├── shader.cpp/.hpp      # Shader manager
    │   └── Shader.vertexshader/.fragmentshader
    ├── model/                   
    │   └── comet.obj       # Falling star 3D model
    ├── stb/                     
    │   └── stb_image.h          # Image loader
    └── textures/                
        ├── earth.jpg
        ├── sun.jpg
        └── moon.jpg

🎓 Project Context

This project was developed within the educational TP Project for the Image Synthesis course in C++/OpenGL.

Project Requirements (Fulfilled):

✅ Animation - Planetary rotations, orbits, falling stars
✅ User Interaction - Camera control, time manipulation, zoom
✅ Lighting - Phong model with dual light sources (Sun + Moon)
✅ Additional Features - Textures, particle systems, OBJ loading

✨ Developed By

By: "[B.Hanaa]" - Final year student in Visual Computing master; passionate about graphics programming.

License: This project is open-source under MIT license. Feel free to use it as a base for your own educational projects!

---

Last Updated: [22-01-2026] Version: 1.0.0
Status: Complete and functional