Voids in Neper

[BjarkeOestergaard]

Describe the bug

When trying to run a through a file (.tesr) with an empty space, the code stops working. I suspect it is due to the voids being inside the grain map. This empty space can be seen in a cross section below:

To Reproduce If i have a simple .tesr file it can still run, but if i introduce voids it does not work. Bash file:

# Converts tesr to tess
neper --rcfile none     -T -n from_morpho \
    -domain "cube(0.025,0.025,0.025)" \
    -morpho "tesr:file(experiement.tesr)"   \
    -oridescriptor euler-bunge \
    -o experiment

example .tesr file which crashes:

***tesr 
 **format 
   2.0 ascii 
 **general 
   3 
   6 6 6
   0.00250 0.00250 0.00250 
 **cell 
   2 
  *id 
   1 2
  *ori 
   ek 
    11.712     24.337    352.981 
    70.090     22.580    317.715 
 **data 
   0 0 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 0 0 2 2 2 2 0 0 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 0 0 2 2 2 2 0 0 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 0 0 2 2 2 2 1 1 2 2 2 2 1 1 2 2 2 2 1 2 2 2 2 2 0 2 2 2 2 2 0 2 2 2 2 2 0 2 2 2 2 2 1 2 2 2 2 2 0 0 2 2 2 0
 ***end 

It gives this error:

========================    N   e   p   e   r    =======================
Info   : A software package for polycrystal generation and meshing.
Info   : Version 4.4.2-9
Info   : Built with: gsl|muparser|opengjk|openmp|nlopt|libscotch (full)
Info   : Running on 48 threads.
Info   : <https://neper.info>
Info   : Copyright (C) 2003-2022, and GNU GPL'd, by Romain Quey.
Info   : Ignoring initialization file.
Info   : ---------------------------------------------------------------
Info   : MODULE  -T loaded with arguments:
Info   : [ini file] (none)
Info   : [com line] -n from_morpho -regularization 1 -domain
         cube(0.0525,0.0525,0.0525) -morpho
         tesr:file(volume_dilated_WholeMap.tesr) -oridescriptor
         euler-bunge -o volume_dilated_WholeMap
Info   : ---------------------------------------------------------------
Info   : Reading input data...
Info   : Creating domain...
Info   : Creating tessellation...
Info   :     [i] Parsing file `volume_dilated_WholeMap.tesr'...
Info   :     [i] Parsed file `volume_dilated_WholeMap.tesr'.
Info   :       . Number of cells: 189
Info   :   - Setting seeds... 100%
100%
Info   :   - Generating crystal orientations...
Info   :       . Listing cell voxels... 100.0%
Run01.sh: line 95: 43127 Aborted                 (core dumped) $NEPER -T -n from_morpho -regularization 1 -domain "cube(0.0525,0.0525,0.0525)" -morpho "tesr:file($name.tesr)" -oridescriptor euler-bunge -o ${name}

Thank you for your amazing tool, and thank you for your time.

Happy holidays and kind regards, Bjarke