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3.14. Region styles

Classes that define geometric regions are derived from the Region class. Regions are used elsewhere in LAMMPS to group atoms, delete atoms to create a void, insert atoms in a specified region, etc. New styles can be created to add new region shapes to LAMMPS.

The files region_sphere.cpp and region_block.cpp and their corresponding headers are representative examples of region style implementations.

Here is a brief description of methods you define in your new derived class. See src/region.h for details.

Required	“pure” methods that must be overridden in a derived class
inside	determine whether a point is in the region
surface_interior	determine if a point is within a cutoff distance inside of surface
surface_exterior	determine if a point is within a cutoff distance outside of surface

Optional	methods that have a default or empty implementation
shape_update	change region shape if set by time-dependent variable
bbox_update	update the bounding box when the shape is variable
init	check style-specific conditions before a run
set_velocity	compute the velocity of a moving region surface
set_velocity_shape	shape-specific part of set_velocity
velocity_contact_shape	return velocity at a contact point for the specific shape
write_restart	write region state to a restart file
restart	read region state from a restart file
length_restart_string	return the size of the restart data
reset_vel	reset velocity when the region is reset