A DirectX 12 renderer featuring a GGX microfacet BRDF.

This project implements a GGX (Trowbridge-Reitz) microfacet BRDF using DirectX 12. It demonstrates physically based rendering techniques on modern graphics hardware.（In Progress: DXR Ray Tracing integration）

Features

• GGX (Trowbridge-Reitz) microfacet BRDF implementation
• Physically based rendering using DirectX 12

🛠 Current Progress & Features

1. PBR Texture Mapping Implementation

In addition to constant material parameters, the renderer now supports full texture-based PBR workflows. This allows for high-fidelity surface detail using maps loaded via Assimp:

• Albedo (Base Color) Map: Defines the raw surface color.
• Normal Map: High-frequency surface detail using Tangent Space normals.
• Metallic / Roughness Map: Pixel-level control of the GGX specular response.

2. GGX Microfacet BRDF

A physically based shading model implemented in HLSL, ensuring realistic light interaction:

• D (NDF): Trowbridge-Reitz GGX for specular distribution.
• G (Geometry): Smith Joint GGX for shadowing and masking.
• F (Fresnel): Schlick's Approximation for view-dependent reflectivity.

$$f(l, v) = \frac{D(h)F(v, h)G(l, v, h)}{4(n \cdot l)(n \cdot v)}$$

🚧 Roadmap (In Progress)

DXR (DirectX Ray Tracing) Integration

I am currently transitioning the project from a pure rasterization pipeline to a hybrid/ray-traced approach using DXR 1.1:

• Acceleration Structures: Building BLAS (Bottom Level) and TLAS (Top Level).
• PBR Implementation: Base logic for GGX.
• Path Tracing: Implementing importance sampling.

Environment

• OS: Windows 11 (64-bit)
• API: DirectX 12
• GPU: NVIDIA GeForce RTX 4060 Ti
• CPU: AMD Ryzen 7 5700X (8-Core)
• Memory: 32 GB RAM
• Windows SDK: 10.0.22621.0

Build

• Visual Studio 2022
• CMake 3.2x

Libraries

• ImGui
• Assimp (v5.2.5)
• DirectXTK12 (oct2025)

Pre-build Configuration

Before running CMake, you must configure the path to the Shader Compiler DLLs (dxcompiler.dll and dxil.dll) which are required for DXR shader signing.

1. Open ./Sample/CMakeLists.txt.
2. Locate the DXC_DLL_PATH variable.
3. Update the path to match your Windows SDK or Visual Studio installation.

# Example: Windows 11 SDK
set(DXC_DLL_PATH "C:/Program Files (x86)/Windows Kits/10/bin/10.0.22621.0/x64")

Cloning & Building

This code is primarily tested with Windows 11 and Visual Studio 2022.
To clone this repo, run the following (note the --recursive flag):

git clone --recursive https://github.com/TomoyaKozuki/DirectX12Renderer_GGX.git

Next, create a build directory and generate the project files using CMake:

cmake -B build -G "Visual Studio 17 2022" -A x64
cmake --build build --config Debug

Alternatively:

cd (PATH_TO_CLONED_REPOSITORY)
mkdir build
cd build
cmake ..

After generating the project, open build/Direct3D12_GGX_Renderer.sln in Visual Studio and run the Direct3D12Renderer project.

License

This project is licensed under the MIT License. See the LICENSE file for details.