This code was written for the semester project of the Physically Based Simulation course in 2015 at ETHZ. The goal was to implement a basic SPH fluid simulator in C++11. Ideas for the implementation are taken from the following papers:

• [1] Weakly compressible SPH for free surface flows
• [2] Predictive-Corrective Incompressible SPH
• [3] Boundary Handling handling and adaptive time-stepping for PCISPH
• [4] Versatile Rigid-Fluid Coupling for Incompressible SPH
• [5] Versatile Surface Tension and Adhesion for SPH Fluids
• [6] Reconstructing Surfaces of Particle-Based Fluids Using Anisotropic Kernels

The following features have been implemented:

• Interactive GUI with basic OpenGL visualization
• JSON based scene description
• Wavefront OBJ support
• Index-sorted uniform grid for neighbour search
• WCSPH [1] and PCISPH [2] solvers
• PCISPH with adaptive time-stepping [3]
• Boundaries using boundary particles [3], [4]
  • Create boundary particles for boxes, spheres and arbitrary meshes
• Surface tension forces [5]
• Fluid mesh generation using marching cubes
  • Isotropic kernel
  • Anisotropic kernel (only works partially yet) [6]
• Cache system to cache particles and meshes
• Render application using either OpenGL visualization or SmallLuxGPU4

a few other videos are here:

• Surface Tension
• Bowl
• Dambreak I
• Dambreak II

The code was tested only on OSX and Linux, but should be easy to get to work on Windows as well. To compile the project on OSX/Linux use the following procedure:

git clone --recursive https://github.com/westlicht/pbsproject.git
cd pbsproject
mkdir build
cd build
cmake ..
make -j8

Now you can start the viewer using:

./viewer ../scenes/bowl.json

Part of the framework was derived from the Nori codebase written by Wenzel Jakob. In addition, the following libraries have been used:

• cxxopts
• Eigen
• filesystem
• json11
• libexecstream
• nanogui
• pcg32
• stb
• tbb
• tinydir
• tinyformat