This project is basically a personal playground for trying out all kinds of rendering stuff, mostly in real-time side.

Currently the goal is to implement a real-time ray-traced physically-based renderer, capable of rendering some procedurally generated meshes and several analytical light sources. After a initial stage, the built-in hybrid pipeline finally produces some 🚀 nice-looking ✨ images. Check the screenshots below!

• A hybrid render pipeline implemented as raytracing-from-G-buffer, for full-dynamic global illumination
• Multi-bounce indirect illumination, accumulated across frames (though noisy and converges slowly ...)
• Stochastic area shadow
• GGX + Lambertian surface shading
• Extensible and platform-agonistic Renderer API*

*: potentially :), since the actual implementation is Windows-only at this time...

Dynamic soft shadows and multi-bounce indirect illumination (accumulated over frames):

You can see how the image converges when the camera is moved (discarding all previous frames):

Latest build, containing sample apps that produce the presented screenshots, can be downloaded on the release page. (Windows Only)

(Notice: in order to run real-time ray-traced samples, you would need a RTX graphic card.)

Requirements:

• CMake 3.13 (or higher),
• Visual Studio 2017 (or higher), with the following components:
  • Game development with C++ (Toolset),
  • Windows 10 SDK 10.0.17763.0 (or higher).
• Most updated driver for your RTX graphic card.

Clone the repository and update submodules, then generate a Visual Studio solution with cmake:

// in repository root directory 
mkdir build
cd build
cmake ../
// open the solution file
ii REI.sln

Now you can build and debug any of the projects under the "REI" solution:

1. Select and set "Samples/rt_raytracing_demo" as start-up project.
2. Press "F5" to build and start debugging. You should be able to see some cuboids and spheres sitting on a thick plane. Try to move the camera with dragging and scrolling.

Here are some excellent articles/papers/talks that help me a lot when I design the abstraction layer and build some of the shinny features:

1. Colin Barré-Brisebois, et al, "Hybrid Rendering for Real-Time Ray Tracing" in <Ray Tracing Gems>. Good reference on how to design a hybrid pipeline utilizing today's not-that-powerful raytracing hardware.
2. Eric Heitz, Stephen Hill and Morgan McGuire, <Combining Analytic Direct Illumination and Stochastic Shadows>. The idea of stochastic (raytraced) shadow for noise-free analytic area lights.
3. Graham Wihlidal, <Halcyon: Rapid Innovation using Modern Graphics>. Shares some great designs decision for an experimental graphic engine.
4. Tomas Akenine-Möller, et al, <Real-Time Rendering>(4th Edition). "The Book" for general real-time topics. Chapter 9 is a comprehensive introduction to physically-based rendering, including an up-to-date overview of PBR practice in real-time application.