🌲 OpenGL 3D Winter Scene

This project is a 3D computer graphics application developed in C++ using OpenGL. It renders a complex, photorealistic winter scene featuring advanced lighting, shadowing, and particle effects.

The application allows users to explore a detailed 3D environment, demonstrating mastery of the graphics pipeline, shader programming, and scene management.

🚀 Key Features

1. Camera & Navigation

• Free Camera: First-person style navigation using Keyboard (WASD) and Mouse.
• Automated Tour: A cinematic camera animation that orbits the central scene (Press P).

2. Advanced Lighting

The scene features multiple light sources managed via GLSL shaders:

• Directional Light (Sun): Simulates global daylight and generates dynamic shadows (Toggle: K).
• Point Lights:
  • Lantern: A static local light source attached to a structure (Toggle: L).
  • Campfire: A dynamic light source with a flickering effect animated in real-time using mathematical functions (Toggle: C).

3. Visual Effects & Photorealism

• Shadow Mapping: Dynamic shadow generation using Depth Map textures and multi-pass rendering.
• Fog: Atmospheric depth effect using an exponential decay function (Toggle: F).
• Particle System (Snow): A custom particle system simulating falling snow, featuring position recycling and specific shaders (Toggle: N).
• Skybox: Cube map rendering for the environment background.

4. Models & Materials

• Loading and rendering of complex .obj models (Windmill, Trees, Cabin, Watchtower, etc.).
• Animations: Continuous rotation of the windmill blades.
• Textures: Diffuse and specular mapping applied to objects.

5. Rendering Modes

Real-time switching between rendering polygons:

• Solid (Standard Fill)
• Wireframe (Lines)
• Point (Vertices)

🎮 Controls

Key	Action
W, A, S, D	Move Camera (Forward, Left, Back, Right)
P	Start/Stop Automated Camera Tour
F	Toggle Fog
N	Toggle Snow Particles
K	Toggle Sun (Directional Light)
L	Toggle Lantern Light
C	Toggle Campfire Light
1	Render Mode: Solid
2	Render Mode: Wireframe
2	Render Mode: Point
ESC	Exit Application

🛠️ Technical Implementation Details

Architecture

• Main Loop: Handles input processing, delta-time calculation, particle updates, and rendering calls.
• Shaders:
  • basic.vert/frag: Implements Blinn-Phong lighting, Shadow calculation, and Fog mixing.
  • depthMap.vert/frag: Renders the scene from the light's perspective to a Framebuffer Object (FBO) for shadow mapping.
  • snow.vert/frag: Dedicated shader for rendering snow particles.
  • skyboxShader: Handles the cubemap background.

Key Algorithms

• Shadow Mapping:
  • Pass 1: Render the scene to a depth texture from the directional light's viewpoint.
  • Pass 2: Render the scene normally, transforming fragments into light space to compare depth values and determine occlusion.
• Particle System (Snow):
  • Manages a vector of SnowParticle structs.
  • Updates positions on the CPU based on velocity and time.
  • Resets particles to the top of the scene when they hit the ground or move out of bounds, ensuring performance efficiency.
• Dynamic Lighting:
  • Campfire intensity is calculated using sin(time) and cos(time) to create a natural fire flickering effect.

📸 Screenshots

📦 Dependencies

• OpenGL 4.1+ (Core Profile)
• GLFW3: Window creation and context management.
• GLEW: OpenGL Extension Wrangler.
• GLM: OpenGL Mathematics library.
• Stb_image: Texture loading utility.

Full documentation here