CRESSim-MPM

CRESSim-MPM is a material point method (MPM) simulation library using CUDA. It is primarily focused on real-time soft body simulation for surgical applications but is also applicable to other domains.

Features

• A light-weight library for real-time MPM simulation.
• Supports:
  • Standard MPM
  • Moving least squares MPM (MLS-MPM)
  • Position-based MPM (PB-MPM)
• Rigid body coupling and contact support (requires external solver for two-way coupling).
• Geometries tailored for surgical simulation, including cutting and suturing.

Requirements

Hardware

• A CUDA-enabled GPU. The code has been tested with compute capability >= 5.0.

Core

• CUDA Toolkit (tested on version 12.6). Any recent version (version 12 or even older versions) should also work.
• CMake (>=3.18)

Optional

The following packages are used in examples and tests.

• glfw for rendering.
• Eigen.

Build Instructions

Basic Build

Clone this repository. Inside the repository, use the following commands:

mkdir build
cd build
cmake .. -DENABLE_DEBUG_LOGGER=ON -DENGINE_STATIC=ON -DENABLE_EXAMPLES=OFF -DENABLE_TESTS=OFF
cmake --build . --config Release

The binaries will be located in build/bin.

Enable Examples and Tests

To enable examples and tests, set the CMake options ENABLE_EXAMPLES and/or ENABLE_TESTS to ON. For example:

cmake .. -DENABLE_DEBUG_LOGGER=ON -DENGINE_STATIC=ON -DENABLE_EXAMPLES=ON -DENABLE_TESTS=ON

To specify the location of Eigen, use EIGEN3_INCLUDE_DIR (absolute path to the directory that contains the folder Eigen). For example:

cmake .. -DENABLE_DEBUG_LOGGER=ON -DENGINE_STATIC=ON -DENABLE_EXAMPLES=ON -DENABLE_TESTS=ON -DEIGEN3_INCLUDE_DIR="path/to/Eigen"

On Windows, the GLFW library path has to be specified with GLFW_LIBRARY_DIR. For example:

cmake .. -DENABLE_DEBUG_LOGGER=ON -DENGINE_STATIC=ON -DENABLE_EXAMPLES=ON -DENABLE_TESTS=ON -DEIGEN3_INCLUDE_DIR="path/to/Eigen" -DGLFW_LIBRARY_DIR="path/to/GLFW/lib-vc2022"

Optionally, the engine can be built as a shared library by changing the CMake option ENGINE_STATIC to OFF.

To change the target CUDA architecture(s), modify the CMAKE_CUDA_ARCHITECTURES value in the CMake cache.

Getting Started

Below is a simple example of creating a simulation scene without soft body particles. For more practical usage, please refer to the code in examples.

#include "simulation_factory.h"

int main()
{
    // Create factory
    crmpm::SimulationFactory *simFactory = crmpm::createFactory(4, 4, 2000, true);

    // Scene description
    crmpm::SceneDesc sceneDesc;
    sceneDesc.solverType = crmpm::MpmSolverType::eGpuMlsMpmSolver;
    sceneDesc.numMaxParticles = 2000;
    sceneDesc.gravity = crmpm::Vec3f(0, -9.81f, 0);
    sceneDesc.gridBounds = crmpm::Bounds3(crmpm::Vec3f(-5.0f, -0.5f, -5.0f), crmpm::Vec3f(5.0f, 5.0f, 5.0f));
    sceneDesc.gridCellSize = 0.2f;
    sceneDesc.solverIntegrationStepSize = 0.002f;
    sceneDesc.solverIterations = 20;

    // Create scene
    crmpm::Scene *scene = simFactory->createScene(sceneDesc);

    // Scene advance
    scene->advance(0.02);

    // Fetch results
    scene->fetchResults();

    // Release scene
    scene->release();
    crmpm::releaseFactory(simFactory);
    return 0;
}

C APIs

To use the C APIs, include the header located in c_api/include. Link against the shared library target crmpm_c_api. As an example, please refer to the code in examples/example_c_api.

Known Issues

• The library is not thread-safe.
• The library does not throw exceptions on error. Instead, an error message will be logged (if built with -DENABLE_DEBUG_LOGGER=ON).
• Triangle mesh processing and collision is not ideal. It may not work for certain types of meshes, especially if the mesh is not watertight.
• CMakeLists.txt files are badly written.

Citation

If you find this project helpful for your research, please consider citing the following paper.

@article{ou2025cressim,
  title={CRESSim-MPM: A Material Point Method Library for Surgical Soft Body Simulation with Cutting and Suturing},
  author={Ou, Yafei and Tavakoli, Mahdi},
  journal={arXiv preprint arXiv:2502.18437},
  year={2025}
}