VolumeSampling¶
The simulator can load particle data from partio files. This particle data then defines the initial configuration of the particles in the simulation. The VolumeSampling tool allows you to sample a volumetric object with particle data. This means you can load an OBJ file with a closed surface geometry and sample the interior with particles using different methods. Especially when simulating elastic solids a good sampling is beneficial as shown by Kugelstadt et al. [2021].
Below are two examples which were generated using the volume sampling tool:
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The tool implements the methods of:
M. Jiang, Y. Zhou, R. Wang, R. Southern, J. J. Zhang. Blue noise sampling using an SPH-based method. ACM Transactions on Graphics, 2015
Tassilo Kugelstadt, Jan Bender, José Antonio Fernández-Fernández, Stefan Rhys Jeske, Fabian Löschner, and Andreas Longva. Fast Corotated Elastic SPH Solids with Implicit Zero-Energy Mode Control. Proceedings of the ACM on Computer Graphics and Interactive Techniques, 2021
Command line options:¶
-h, –help: Print help
-i, –input arg: Input file (obj)
-o, –output arg: Output file (bgeo or vtk)
-r, –radius arg: Particle radius (default: 0.025)
-s, –scale arg: Scaling of input geometry (e.g. –scale “2 1 2”) (default: 1 1 1)
-m, –mode arg: Mode (regular=0, almost dense=1, dense=2, Jiang et al. 2015=3, Kugelstadt et al. 2021=4) (default: 4)
–region arg: Region to fill with particles (e.g. –region “0 0 0 1 1 1”)
–steps arg: SPH time steps (default: 100)
–cflFactor arg: CFL factor (default: 0.25)
–viscosity arg: Viscosity coefficient (XSPH) (default: 0.25)
–cohesion arg: Cohesion coefficient
–adhesion arg: Adhesion coefficient
–stiffness arg: Stiffness coefficient (only mode 3) (default: 10000.0)
–dt arg: Time step size (only mode 3) (default: 0.0005)
–res arg: Resolution of the Signed Distance Field (e.g. –res “30 30 30”)
–invert: Invert the SDF to sample the outside of the object in the bounding box/region
–no-cache: Disable caching of SDF.
Example:¶
VolumeSampling.exe --mode 4 -i ..\data\models\bunny.obj -o bunny.vtk