README.md

MPM Simulation & Voxels Rendering

This is the final project for the course, General-Purpose GPU Programming @ NTU CSIE.

We model and simulate fluid-like materials, such as snow and sand, using material point method. MPM is implemented in C++ & CUDA. And OpenGL is used for real-time result viewing. Besides, for high quality rendering, we use NVIDIA GVDB + OptiX Ray Tracing Engine.

Overview

The material point method (MPM) is a numerical technique used to simulate the behavior of solids, liquids, gases, and any other continuum material. In the MPM, a continuum body is described by a number of small Lagrangian elements referred to as 'material points'. These material points are surrounded by a background mesh/grid that is used only to calculate gradient terms such as the deformation gradient. For more information, please go to Material point method - Wikipedia

Implementations

For more details about implementation, please go to our Project Page

Dependencies

Required

• CUDA
• OpenGL
• GLFW
• OpenGL Mathematics (GLM)

The following libraries has been put into this repository,

• Eigen
• svd3
• stb_image
• glad

Optional

For high quality rendering as screenshots,

• GVDB-Voxels
• NVIDIA OptiX

To generate videos from saved rendered frames,

• FFmpeg

How to Build

Source code are put in inc/ and src/. To compile the simulation program, simply type make. Compiled objects would appear in obj/, and there would be the executable file in root directory of the repository.

To compile the rendering program, GVDB-Voxels library and Nvidia OptiX ray tracing engine are needed. So please build gvdb-library at first. Then build the code in directory, gPointCloud/, which is modified from the sample code. For more information, please go to NVIDIA/gvdb-voxels.

How to Run

First of all, run make to generate the executable. Then prepare your own configuration file with format as follows:

model=MODEL

where MODEL is a JSON file formatted as:

{
  "model1": {
    "path": "PATH",
    "translate": [50.0, 0.0, 50.0],
    "scale": 0.5,
    "mass": 0.000026,
    "velocity": [0.0, -10.0, 0.0],
    "hardening": 15.0,
    "young": 1.4e5,
    "poisson": 0.2,
    "compression": 5.0e-2,
    "stretch": 5.0e-2
  }
}

The PATH is the ascii point cloud file where each line contains three values x y z seperated by a single space, and other parameters depend on your model setting. Finally, run

./test --config CONFIG_FILE

to simulate using MPM and render with OpenGL!

Screenshots

Letters falling scene

Two snow balls crashed each other

References

Papers

• Multi-species simulation of porous sand and water mixtures
• A material point method for snow simulation

Other Implementations

• Azmisov - snow
• JAGJ10 - Snow
• utilForever - SnowSimulation

Contact

Issues and pull requests are welcomed, so are stars! ^_^ Feel free to contact project owner Sung Tzu-Wei, or contributors Yist Lin and Chen Li-Yu.