Doku gcad3d_gMsh                            CadCam-Services Franz Reiter 

Program gMsh1 Version 1.12 / 2022-06-09


Purpose: create mesh from points and lines, inner-boundaries and outer-boundary.
  All input-data is read from textfiles. See:
  File_format_points
  File_format_breaklines_boundaries
  File_format_meshfile-gcad
  File_format_meshfile-dxf
  File_format_controlfile



Program-structure:
  gcad3d-plugin gMsh1 - does:
    start executable GUI_gMsh1  (see Exe_GUI_gMsh1)
      GUI_gMsh1 displays menu for file-selection, creates controlfile
    start executable gcad3d_gMsh -
      gcad3d_gMsh creates meshfile (see Exe_gcad3d_gMsh)
    display meshfile



Example_using:
- start plugin gMsh1 (Plugin/gMsh1) or restart plugin with Ctrl-P
- select Controlfile (button select or button edit)
    - edit to add / use setenv - record(s), files with symbolic directories;
    - file-format see File_format_controlfile
    - click into entry under "Controlfile:" to enter new controlfilename
- select pointfile
    - click button under "filename-points", select a file (double-click),
- select checkbox "PT" to display point-ID's
- click button "Mesh"

- key Ctrl-P                - in grafic-window, restart plugin
- click button "ViewLog"    - display logfile for last mesh


========================================================
File_format_points
  one line in file describes one point;
  3 floats per line; example:
56,-53794.775,352988.157,299.1700


========================================================
File_format_breaklines_boundaries
  one line in file describes one linesegment;
  6 floats per line; example:
-53752.162961,352943.624041,0.000000,-53767.243715,352944.934356,0.000000


========================================================
File_format_meshfile-gcad
  the first lines can be errormessages, starting with "# ERROR <errormessage>"
  followed by:
- section points ("SECTION PTAB _<pointSetName>")
  - lists all points, ends with "SECTIONEND"

- section mesh ("SECTION MESH _<meshName>")
  - lists all faces and edgelines, ends with "SECTIONEND"
  - edgetypes:
      edgetyp=1    breakline, user defined
      edgetyp=2    outer-boundary, automatic created
      edgetyp=3    inner-boundary, user defined
      edgetyp=4    outer-boundary, user defined
      edgetyp=5    inner-boundary, computed points
      edgetyp=6    outer-boundary, computed points
  
<pointSetName>=PTAB
<meshName>=MSH <pointSetName>



========================================================
File_format_meshfile-dxf

- export of faces as 3DFACE
- export of lines as POLYLINE - VERTEX
- export of points as POINT (3D)



========================================================
File_format_controlfile

   filetype of controlfiles is ".gmsh1"

# Optional: define symbolic direcories; Example:
setenv MSHDIR /home/test/gCAD3D/gMsh1/
# use symbol for filenames eg:
# ms_pt $MSHDIR/pt1.dat

# System-variables can be used for setenv; Linux: $varnam; MS: %varnam%

# Optional: define filename for the logfile;
# Default is actMdl.log in the directory of the commandfile
logfile <filename-logfile>

# Optional: define filename for outputfile (mesh, points, curves);
# Default is actMdl.gcad (or actMdl.dxf) in the directory of the commandfile
# Using command outfile do not add a filetype -
#   - "gcad" or "dxf" will be added according to the cad-format
outfile <filename-meshfile>

# The commands setenv logfile and outfile have to be defined with the Editor.
# These commands must be before the following commands set by GUI.

# Optional: set cad-format of output: "gcad" (the default) or "dxf"
outfmt <cad-format>

# do not display faces (default is to display faces)
no_disp_fac

# display face-centerpoints
disp_fce

# display points
disp_pt

# display breaklines
disp_bl

# display input-breaklines
disp_blIn

# display outer-boundary and inner-boundaries
disp_bd

# display input-boundaries (outer-boundary and inner-boundaries)
disp_bdIn


# The default-input- and output-directory for all files is the directory of
#   this commandfile.
# Symbolic diretctory must be used with preceding '$'-character. See setenv above.


# pointfile
ms_pt <filename-pointfile>

# file breaklines
ms_bl <filename-breaklines>

# inner-boundaries
ms_ib <filename-inner-boundary>

# outer-boundary
ms_ob <filename-outer-boundary>

# Optional: define name of pointset (identification of section points)
pt_def_id <pointSetName>

# Optional: define name of mesh (identification of section mesh)
ms_def_id <meshName>



========================================================
Exe_GUI_gMsh1
  - executable exists for Linux and MS-Windows
  - displays menu for file-selection, creates controlfile
  - default directory for all files is Data/gMsh/
    - Data is a symbolic directory, default is $HOME/gCAD3D/dat/
  - filetype of controlfiles is ?


========================================================
Exe_gcad3d_gMsh
  - executable exists for Linux and MS-Windows
  - input is a controlfile (see File_format_controlfile)
  - creates meshfile, format gcad or dxf
    - default-filename - Linux: /tmp/actMdl.gcad or /tmp/actMdl.dxf
    - see File_format_meshfile-gcad or File_format_meshfile-dxf 



# eof