Fluid-Sim

Fluid Simulation on the GPU based on the Navier-Stokes equations for incompressible flow.

Setup

OpenGL 4.5

C++ 20 (Builds with Clang and MSVC on Windows using CMake)

vcpkg for dependencies (currently glfw + glm)

Output.mp4

Features

Velocity, Dust/Smoke Density, Temperature

Advection

• Semi-Lagrangian (reverse) advection
  • Euler or 4th order Runge-Kutte
• Optionally: Back and forth error compensation and correction

Buoyancy and Gravity

Pressure Projection

• Basic Jacobi
• Basic Red-Black Gauss-Seidel
• Multigrid Jacobi
  • Only very basic restriction/interpolation schemes so far
    • Full-Weighting as outlined in "A Multigrid Tutorial" is implemented on the multigrid branch, but im not yet sure if totally correct

Rendering

• Brute Force Raymarcher following: https://shaderbits.com/blog/creating-volumetric-ray-marcher

TODO

• Try using Gauss-Seidel iterations as smoother for the multigrid solver
• Expose more parameters to the UI (especially Buoyancy/Gravity)
• Stagger divergence and pressure attributes on grid
• optimize everything!
  • shaders currently follow forumlas closely so its easier to understand but that also means theres big room for improvement
  • also test using groupshared memory for most passes since everything seems to be texture fetch bound
• ...