Error while using transform-cut-cubei

[shahul31]

Hello,

Problem: Error occurred while trying to transform->cut->cubei a 1000 nos grain structure.

Purpose: I am computing a periodic tessellation in FEPX after meshing in Neper, but the meshed periodic model doesn't have a flat surface to apply boundary conditions (also FEPX requires order 2 meshed elements and it is not working with hex elements). I am trying to transform the periodic tessellation cut along the edges, which does not work now. So exploring in non-periodic tessellation first and the below bug occurred.

Please help!!

$neper -T -n 1000 -transform "cut(cubei(0.2,1,0.2,1,0.2,1))" -o cut2

========================    N   e   p   e   r    =======================
Info   : A software package for polycrystal generation and meshing.
Info   : Version 4.4.2-4
Info   : Built with: gsl|muparser|opengjk|openmp|nlopt|libscotch (full)
Info   : Running on 4 threads.
Info   : <https://neper.info>
Info   : Copyright (C) 2003-2022, and GNU GPL'd, by Romain Quey.
Info   : No initialization file found (`/home/shahul/.neperrc').
Info   : ---------------------------------------------------------------
Info   : MODULE  -T loaded with arguments:
Info   : [ini file] (none)
Info   : [com line] -n 1000 -transform cut(cubei(0.2,1,0.2,1,0.2,1)) -o
         cut2
Info   : ---------------------------------------------------------------
Info   : Reading input data...
Info   : Creating domain...
Info   : Creating tessellation...
Info   :   - Setting seeds... 
Info   :   - Generating crystal orientations...
Info   :   - Running tessellation...
Info   : Transforming tessellation...
Info   :   - Cutting (experimental)...
Info   :     > hspace(-0.2,-1,0,0)...
Info   :     > hspace(1,1,0,0)...
Info   :     > hspace(-0.2,0,-1,0)...
Info   :     > hspace(1,0,1,0)...
Info   :     > hspace(-0.2,0,0,-1)...
Info   :     > hspace(1,0,0,1)...
Info   :     [o] Writing file `tess.debug'...
face = 5756
edges = 1497 1496 1498 1643 1644 1645 1646 1647 2124 2128 2397 2399 3307 3308 3309 3310 3311 3482 3483 3712 3713 3932 3933 3934 3939 4809 5169 6115 6880 8294 8330 8331 8741 8742 8744 8844 8972 8973 8974 9066
Info   :     [o] Wrote file `tess.debug'.
Error  : You have discovered a bug in Neper!  Please file an issue at
         https://github.com/rquey/neper/issues.  Thank you.

[rquey]

This specific error occurs because you are cutting at x=1, y=1 and z=1, which coincide with boundary planes of the domain. Cutting at other values would work.

[shahul31]

Thank you very much.