## Vgrid

Syntax:

        set vgrid $gridname {size N}
        unset vgrid $gridname
        show vgrid

If the named grid already exists, mark it as active (use it for subsequent vfill and voxel operations). If a new size is given, replace the existing content with a zero-filled N x N x N grid. If a grid with this name does not already exist, allocate an N x N x N grid (default N=100), zero the contents, and mark it as active. Note that grid names must begin with '$'.

show vgrid lists all currently defined voxel grids. Example output:

         $vgrid1: (active)
                  size 100 X 100 X 100
                  vxrange [-4:4]  vyrange[-4:4]  vzrange[-4:4]
                  non-zero voxel values:  min 0.061237 max 94.5604
                  number of zero voxels:  992070   (99.21%)

unset vgrid $gridname releases all data structures associated with that voxel grid. The data structures are also released by reset session. The function voxel(x,y,z) returns the value of the active grid point nearest that coordinate. See also splot voxel-grids (p. ).