Monti is a Vulkan path tracer with an ML denoiser, interactive viewer, and headless training data generator.

• CMake 3.22+
• C++20 compiler — MSVC 2022 (v17.x), GCC 12+, or Clang 15+
• Vulkan SDK — install from https://vulkan.lunarg.com/sdk/home and ensure VULKAN_SDK is set (provides vulkan.h and glslc)
• Git — required for FetchContent dependency downloads; also for extended scene sparse checkout
• GPU — NVIDIA RTX series recommended (ray tracing + ML denoiser). Any Vulkan 1.2 GPU with VK_KHR_ray_tracing_pipeline works for the path tracer

All C++ dependencies are fetched automatically by CMake (VMA, GLM, SDL3, Dear ImGui, FreeType, Catch2, CLI11, volk, tinyexr, stb, FLIP, MikkTSpace, nlohmann/json).

cmake -B build
cmake --build build --config Release

This builds everything: monti_view (interactive viewer), monti_datagen (headless data generator), monti_tests, and all core libraries. Khronos glTF test assets, extended Cauldron-Media scenes, and benchmark scenes are downloaded automatically during configuration. All C++ dependencies are fetched via CMake FetchContent.

To skip the applications and heavy scene downloads:

cmake -B build -DMONTI_BUILD_APPS=OFF -DMONTI_DOWNLOAD_EXTENDED_SCENES=OFF -DMONTI_DOWNLOAD_BENCHMARK_SCENES=OFF
cmake --build build --config Release

CMake caches option values. To pick up new defaults after editing CMakeLists.txt:

Remove-Item build/CMakeCache.txt
cmake -B build
cmake --build build --config Release

Downloaded automatically when MONTI_DOWNLOAD_TEST_ASSETS=ON (the default) into scenes/khronos/. Includes 12 GLB models (ABeautifulGame, AntiqueCamera, BoomBox, ClearCoatTest, DamagedHelmet, DragonAttenuation, Lantern, MaterialsVariantsShoe, MosquitoInAmber, SheenChair, ToyCar, WaterBottle) and 2 multi-file glTF models (FlightHelmet, Sponza) fetched via Git sparse checkout.

Downloaded automatically into scenes/extended/Cauldron-Media/ via Git sparse checkout of GPUOpen-LibrariesAndSDKs/Cauldron-Media. Fetches AbandonedWarehouse, BistroInterior, and Brutalism. These are multi-GB downloads. Disable with -DMONTI_DOWNLOAD_EXTENDED_SCENES=OFF if bandwidth is limited.

Environment maps (HDR/EXR) go in scenes/environments/. This directory is gitignored. For standalone object scenes that have no embedded lighting, an environment map is required.

Download CC0 HDRIs from Poly Haven and place them in scenes/environments/:

mkdir scenes\environments
# Example: download studio_small_09_2k.exr from Poly Haven

The trained model deni_v3.denimodel lives in denoise/models/. CMake copies it to build/deni_models/ at build time. The denoiser auto-discovers the model at runtime — no path configuration needed.

If you need to install a model from another source (e.g., a sibling repo where training was performed):

copy <source-repo>\denoise\models\deni_v3.denimodel denoise\models\deni_v3.denimodel
cmake --build build --config Release --target deni_model

In monti_view, switch the denoiser mode from Passthrough to ML in the UI to use the model. The denoiser timing is displayed in the UI panel.

build\Release\monti_view.exe scenes\khronos\DamagedHelmet.glb
build\Release\monti_view.exe scenes\khronos\DamagedHelmet.glb --env scenes\environments\studio_small_09_2k.exr

build\Release\monti_datagen.exe --scene scenes\khronos\DamagedHelmet.glb --output training_output

After a fresh clone and build, golden reference images must be generated before tests pass. These are high-SPP renders stored in tests/golden/ and used by the golden validation tests:

build\Release\monti_tests.exe "[golden_gen]"

This renders each test scene at 1024 SPP and writes reference PNGs. The generation tests are skipped by default — only the validation tests run automatically. This step only needs to be repeated if the rendering pipeline changes.

Tests are split into batches to avoid GPU resource exhaustion:

cmake --build build --config Release --target run_all_tests

cmake --build build --config Release --target run_tests_core      # Core tests
cmake --build build --config Release --target run_tests_golden    # Golden reference tests
cmake --build build --config Release --target run_tests_extended  # Extended scene tests
cmake --build build --config Release --target run_tests_deni      # Denoiser + numerical tests

build\Release\monti_tests.exe                          # All tests
build\Release\monti_tests.exe "[deni]"                 # Denoiser tests only
build\Release\monti_tests.exe "~[extended]~[golden]"   # Skip heavy tests

cd build
ctest -C Release