Merian-Quake

A path-tracer for the original Quake game on top of quakespasm and Merian.

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This project showcases a novel real-time path guiding algorithm. For a comprehensive description of the algorithm and the inner workings of this project, please refer to the paper and the project website:

Lucas Alber, Johannes Hanika, and Carsten Dachsbacher. 2025. Real-Time Markov Chain Path Guiding for Global Illumination and Single Scattering. Proc. ACM Comput. Graph. Interact. Tech. 8, 1, Article 15 (May 2025), 18 pages. https://doi.org/10.1145/3728296

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Maps in screenshots: start from Alkaline and ad_azad, ad_sepulcher, ad_tears from Arcane Dimensions.

Licensing

This project is licensed under GPLv2. The code for Markov Chain Path Guiding (/res/shader/render_mcpg) is licensed under GPLv3. The code for ReSTIR (/res/shader/render_restir) and Screen-Space Mixture Models (/res/shader/render_ssmm) is licensed under the BSD 3-Clause License.

Get in touch if you are interested in a different licensing model.

Requirements

This project requires a GPU with ray tracing support (Vulkan Ray Query).

Tested: NVIDIA GeForce RTX 2080 / 3070 TI / 3080 TI / 4080 TI, AMD Radeon RX 6800 XT, AMD RX 7900 XTX and Intel Arc.

Usage

This project builds on quakespasm, follow the instructions there on how to install the necessary .pak files.

merian-quake <quakespasm arguments>

You can specify the path to your quake folder using the -basedir argument if you do not want to use the default.

Building and Installing

Supported OS:

• Windows 11
• Linux

Build dependencies:

• Vulkan SDK
• Meson
• A fairly recent C++ compiler (Visual Studio Build Tools on Windows)

# Clone the repository with all submodules:
git clone --recursive https://github.com/LDAP/merian-quake
cd merian-quake

# Configure and compile
meson setup build [--prefix=path/to/installdir]
# or debug
meson setup build [--prefix=path/to/installdir] --buildtype=debug
# on windows you might need to add --backend vs or set the compiler to cl (MSVC) using environment variables

meson compile -C build

# Install
meson install -C build

Development

# Unix
# Just run
./build/merian-quake [-basedir /path/to/quakedir]

# Windows: (requires .dll paths set up correctly)
meson devenv -C build
./merian-quake [-basedir /path/to/quakedir]

Note, the quakedir is the folder that contains the id1 subfolder.