create_multisphere_clump command¶

Syntax¶

create_multisphere_clump dmin dstyle dvalue rmin rvalue pmax pvalue seed svalue surfacefile file keyword values filetype fileargs

dmin = obligatory keyword
dstyle = absolute or radius_ratio
dvalue = minimum distance between spheres and next surface point used for sphere generation
rmin = obligatory keyword
rvalue = minimum sphere radius
pmax = obligatory keyword
pvalue = maximum fraction of surface points used for sphere generation
seed = obligatory keyword
svalue = random number seed
surfacefile = obligatory keyword
file = surface file name
zero or more keyword/value pairs may be appended

keyword = invert_normals or subdivide

invert_normals value = yes or no
subdivide values = style N
  style = linear or loop or butterfly
  N = number of subdivision iterations

one output filetype must be appended

filetype = clumpfile or datafile

clumpfile args = filename
datafile args = filename atom_type density
  filename = data filename
  atom_type = atom type (optional)
  density = particle density (optional)

Examples¶

create_multisphere_clump dmin absolute 0.0002 rmin 0.002 pmax 1.0 seed 2133421 surfacefile meshes/infile1.vtk clumpfile data/clump1.dat

Description¶

This command creates a multi-sphere clump from a VTK, STL or PLY surface mesh file and writes the clump data to a file. The VTK library is used to read an STL file, a PLY file, or an unstructured grid or polydata dataset from VTK simple legacy or XML files. The polygons of the surface mesh are triangulated and optionally the surface is subdivided. Finally, the overlapping multi-sphere clump method (OMCM, see Ferellec) is used to generate a clump configuration which is then written to a clump or data file.

Restrictions¶

Requires LIGGGHTS to be linked to the VTK library.

Default¶

invert_normals = yes, subdivide = off, atom_type = 1, density = 1000

(Ferellec, 2010) “A method to model realistic particle shape and inertia in DEM”, J.F. Ferellec and G.R. McDowell, Granular Matter (2010) 12:459–467