Sloshing-3D

Real-time interactive 3D sloshing tank simulation using CLSVOF (Coupled Level Set / Volume of Fluid) on a MAC staggered grid, rendered with marching cubes and OpenGL 4.1.

Features

• CLSVOF interface tracking — level set for geometry, VOF for conservation, coupled each timestep
• MAC staggered grid with PCG pressure solver and MIC(0) preconditioning
• Semi-Lagrangian advection (RK2) for velocity and level set
• TVD Superbee VOF transport — conservative flux-form with directional splitting
• Marching cubes rendering with Phong + Fresnel shading, MSAA, and wall caps
• Persistent thread pool — parallel grid operations with no per-frame allocation
• Mouse-driven interaction — drag to shake, Option+drag to tilt, scroll to zoom
• Physics-validated — standing wave frequency, amplitude retention, volume conservation

Building

Requires CMake 3.20+ and a C++20 compiler. All other dependencies (GLFW, GLM, glad, GoogleTest) are fetched automatically.

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Running

./build/sloshing3d              # Default 32x16x32 grid
./build/sloshing3d 48 24 48    # Custom resolution

Controls

Input	Action
Drag	Shake the tank
Option+drag	Tilt the tank (rotates gravity)
Scroll	Zoom
R	Reset simulation
F	Reset camera and tilt
Esc	Quit

Tests

cmake --build build --target sloshing_tests
ctest --test-dir build

28 tests covering PLIC geometry, VOF conservation, level set reinitialization, CLSVOF coupling, pressure solver correctness, and physics validation:

• 1.1% frequency error vs analytical shallow-water theory
• 67.5% amplitude retention over 4 wave periods
• Volume conservation to machine precision (~10^-12 relative error)

Documentation

doxygen Doxyfile
open docs/html/index.html

Project Structure

include/sloshing/
  grid.h               MAC staggered grid, Array3D, cell classification
  simulation.h         Timestep driver, adaptive CFL, body forces
  pressure_solver.h    PCG + MIC(0) Poisson solver
  advection.h          Semi-Lagrangian advection, TVD VOF, PLIC geometry
  clsvof.h             Level set / VOF coupling, reinitialization
  renderer.h           OpenGL rendering, marching cubes, camera
  parallel.h           Thread pool, parallel_for, parallel_reduce
  fluid_utils.h        Ghost fluid theta, smooth Heaviside, WENO5
src/
  *.cpp                Implementations (~4200 lines total)
tests/
  test_*.cpp           28 unit and physics validation tests

License

Free for personal, academic, and research use. No warranty. Commercial use requires written permission from the author.