EchoEngine

A modern 3D rendering engine built with C++20 and OpenGL 4.6, demonstrating physically-based rendering (PBR) techniques with a deferred rendering pipeline (and forward for transparent objects)

Features

Rendering Pipeline

• Deferred / Forward: Opaque objects use deferred shading; transparent objects use forward rendering
• Physically-Based Rendering: Cook-Torrance BRDF with metallic-roughness workflow
• Image-Based Lighting: Environment cubemap, irradiance map, prefilter map, BRDF LUT
• Screen-Space Ambient Occlusion: Kernel-based SSAO with bilateral blur
• Skybox Rendering: Environment cubemap with seamless transitions
• Atmosphere Rendering: Single and Multi scattering atmospheric rendering using LUTs
• Shadow mapping: Shadow mapping & volumetric shadowing

Asset Management

• OBJ/MTL Model Loading: Full support for Wavefront OBJ format with material libraries
• Texture Loading: PNG/JPG support via STBImage
• Resource Caching: Lazy loading and GPU upload on-demand

Tools & Debugging

• Debug UI: ImGui-based scene inspector and texture debugger
• Performance Monitor: Real-time FPS counter and frame time graph
• Hot Reloading: Live shader reloading with R key
• GPU Texture Debugger: Visualize G-Buffer targets, SSAO outputs, and material cache

Atmosphere is currently missing proper irradiance and specular

Morning	Noon
Night	Volumetric shadowing (lightshafts)

Quick Start

Prerequisites

• C++20 compatible compiler (GCC 10+, Clang 12+, MSVC 2019+)
• CMake 3.16 or higher
• OpenGL 4.6 compatible graphics driver

Building

Linux/macOS

git clone https://github.com/Auria-dev/EchoEngine.git
cd EchoEngine
chmod +x run.sh
./run.sh

Windows

git clone https://github.com/Auria-dev/EchoEngine.git
cd EchoEngine
run.bat

Manual Build

mkdir build && cd build
cmake .. -G Ninja
ninja
./EchoEngine

Controls

Action	Key
Move Forward	W
Move Backward	S
Move Left	A
Move Right	D
Move Up	Space
Move Down	Left Shift
Toggle Cursor	Enter
Fullscreen	F11
Reload Shaders	R
Quit	Escape

Dependencies

Library	Version	Purpose
GLFW	3.x	Window creation and input handling
Glad	-	OpenGL 4.6 function loader
GLM	-	Mathematics library for 3D graphics
ImGui	Docking Branch	Debug UI and scene inspector
STBImage	-	Image loading (PNG/JPG)

All "heavy" (large) models are from jvm-graphics-labs/awesome-3d-meshes

All contributions are welcome! Please feel free to submit issues and pull requests.

License

This project is provided as-is for educational and demonstration purposes.

---

GLAD configuration used: glad.dav1d.de