Work in progress. A solo research engine (Jan–Apr 2026). It runs on Windows with a Vulkan 1.3 GPU. See Known limitations.
GPU-raymarched voxel engine with real-time destruction, procedural terrain and rigid-body physics. Simulation is C23; the Vulkan renderer is C++23 and only reads simulation state.
Day/night cycle · a pillar cut at its base topples as a rigid body · F4 debug views · rain, snow and fireflies by climate and time of day
- Compute-shader raymarching: hierarchical DDA over chunk and region occupancy bitmasks; dynamic voxel objects traced through a BVH.
- Deferred pipeline: G-buffer with motion vectors (world positions rebuilt from depth), raymarched shadows (a ray or two per pixel and frame) and AO with temporal accumulation, spatial denoising, TAA over a jittered projection; water tinted by its material.
- Destruction: voxel edits trigger connectivity analysis; disconnected islands detach into rigid bodies with debris.
- Physics: rigid bodies with GJK/EPA on QuickHull convex hulls, sweep-and-prune broadphase, fixed 60 Hz step, drawn interpolated between steps.
- Procedural world: FBM and ridged-noise terrain, 9 temperature/humidity biomes, 18 parametric tree species, flora scatter, water fill, day/night cycle, weather, 8 ambient particle types. A job system generates the world on every hardware thread in about 0.17 s, identical for any thread count, while the loading screen keeps drawing.
- Tests: 305 CPU tests in 16 executables covering physics, connectivity, detachment, world generation (identical for any thread count), the job system, profiling budgets and CPU/GPU struct layouts, plus app launch and GPU frame-time tests. A GitHub Actions workflow builds Release and Debug (profiler compiled out) with MSVC, warnings as errors, and runs the CPU tests.
| Area | State |
|---|---|
| Renderer | Working on Windows; Debug builds run clean under the Khronos validation and synchronization-validation layers |
| Destruction & physics | Working; simple impulse solver (see limitations) |
| World generation | One fixed-size world (~154 × 38 × 154 m), no streaming |
| Platforms | Windows |
- Windows-only app (Win32 window).
- One fixed-size, densely stored world. Launch to a playable world takes under a second in Release on an i9-14900HX; generation is 0.17 s on its 32 hardware threads (1.5 s on one).
- Physics uses a single-pass impulse solver with a diagonal inertia tensor: no joints, no continuous collision, and terrain contact samples box points; objects stacked on other objects rock slightly and never sleep (single-point contacts).
- Portable window layer (GLFW or SDL) for Linux
- Sparse chunk storage and world streaming
- Iterative contact solver with multi-point manifolds and warm starting
Requires Windows 10 (1703) or later, CMake 3.21+, Ninja, MSVC (Visual Studio 2022 or later) or clang-cl, a Vulkan 1.3 GPU, and the Vulkan SDK. Run the commands below from a Developer Command Prompt (x64), or run build.bat, which finds Visual Studio itself, configures, builds and runs the unit tests (build.bat help lists the other commands).
git clone --recursive https://github.com/rmguney/patch
cd patch
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build
build\patch_samples.exeThe app starts in borderless fullscreen; build\patch_samples.exe --windowed starts in a resizable window instead (--windowed 1600 900 sets its client size in pixels).
set PATCH_MONITOR=1 opens the window on another monitor (0 or unset: the primary; 1, 2, ...: the others, left to right); scripted test runs open there without taking the keyboard focus.
No shader compiler (glslc)? Add -DPATCH_USE_PREBUILT_SHADERS=ON to use the checked-in SPIR-V; the Vulkan headers and loader are still required. Debug builds enable the Vulkan validation layers when the SDK is installed.
Tests (the launch and render_perf tests start the app and need a GPU):
ctest --test-dir build --output-on-failure -E "launch|render_perf"Add -DPATCH_RUN_TESTS_ON_BUILD=ON to run the unit tests after every app build. Wall-clock budget asserts only warn under plain ctest (shared CI runners are noisy); set PATCH_STRICT_PERF=1 to make them fail, as the opt-in post-build test run does.
| Input | Action |
|---|---|
| Left mouse (hold) | Destroy voxels under the cursor |
| Right mouse (click) | Throw a random voxel shape |
| Right mouse (drag) | Look around |
| WASD, Space / Shift | Move; up / down |
| F2 | Debug overlay: profiler, time-of-day and weather presets |
| F3 | Write debug_report.txt (in a scene) |
| F4 / F5 | Next / previous terrain debug view |
| F11 or Alt+Enter | Switch between borderless fullscreen and a resizable window |
| Esc | Pause and resume |
engine/core/ Math, RNG, noise, job system, profiling, spatial hashing
engine/voxel/ Volume storage, occupancy and shadow mips, connectivity
engine/sim/ Scene management, detachment, background loading, env particles, menu state
engine/physics/ Rigid body, collision, particles
engine/render/ Vulkan renderer (render passes as subsystems, barrier helper), UI
engine/platform/ Window and input (Win32), timing and threads (Win32 / POSIX)
content/ Materials, shapes, scene descriptors
game/ World scene, biomes, terrain / tree / shrub / scatter generation, weather, day/night
shaders/ GLSL compute, vertex and fragment shaders
app/ Application entry point
voxelize converts an OBJ mesh to a C voxel shape:
build\voxelize.exe model.obj output.c --resolution 16Captures from the legacy scenes kept under .github/legacy (ball pit, melee, shooter).
