Dear list members,
I have encountered some unusual behavior while trying to generate a very
simple structured tetrahedral mesh for two boxes. The attached images
show the surface (triangle) and volumetric (tetrahedron) elements of the
same mesh. However, some of the triangles do not "sit" properly on the
face of the corresponding tetrahedron but they are "laid across" on two
tetrahedra. This is marked with red arrows on the images. I have also
attached the script resulting this mesh.
I generated these pictures using gmsh version 2.9.1 but some other
versions also produce the same problem.
Thank you for your help,
Jozsef Kophazi
//////// Configuration block ////////
// Possible values:
// lores 0.1
// mdres 0.025
// mhres 0.010
// hires 0.005
den=0.1;
top_structured=1;
top_hex=0;
bottom_structured=1;
bottom_hex=0;
alternate=0;
//////// End of configuration block ////////
// Points
blb_point = newp; Point( blb_point) = { 0.0, 0.0, 0.0, den};
flb_point = newp; Point( flb_point) = { 1.0, 0.0, 0.0, den};
brb_point = newp; Point( brb_point) = { 0.0, 1.0, 0.0, den};
frb_point = newp; Point( frb_point) = { 1.0, 1.0, 0.0, den};
blm_point = newp; Point( blm_point) = { 0.0, 0.0, 0.5, den};
flm_point = newp; Point( flm_point) = { 1.0, 0.0, 0.5, den};
brm_point = newp; Point( brm_point) = { 0.0, 1.0, 0.5, den};
frm_point = newp; Point( frm_point) = { 1.0, 1.0, 0.5, den};
blt_point = newp; Point( blt_point) = { 0.0, 0.0, 1.0, den};
flt_point = newp; Point( flt_point) = { 1.0, 0.0, 1.0, den};
brt_point = newp; Point( brt_point) = { 0.0, 1.0, 1.0, den};
frt_point = newp; Point( frt_point) = { 1.0, 1.0, 1.0, den};
// Lines
rb_line = newl; Line( rb_line) = {frb_point, brb_point};
bb_line = newl; Line( bb_line) = {brb_point, blb_point};
lb_line = newl; Line( lb_line) = {blb_point, flb_point};
fb_line = newl; Line( fb_line) = {flb_point, frb_point};
rm_line = newl; Line( rm_line) = {frm_point, brm_point};
bm_line = newl; Line( bm_line) = {brm_point, blm_point};
lm_line = newl; Line( lm_line) = {blm_point, flm_point};
fm_line = newl; Line( fm_line) = {flm_point, frm_point};
rt_line = newl; Line( rt_line) = {frt_point, brt_point};
bt_line = newl; Line( bt_line) = {brt_point, blt_point};
lt_line = newl; Line( lt_line) = {blt_point, flt_point};
ft_line = newl; Line( ft_line) = {flt_point, frt_point};
frt_line = newl; Line(frt_line) = {frt_point, frm_point};
frb_line = newl; Line(frb_line) = {frm_point, frb_point};
brb_line = newl; Line(brb_line) = {brb_point, brm_point};
brt_line = newl; Line(brt_line) = {brm_point, brt_point};
blb_line = newl; Line(blb_line) = {blb_point, blm_point};
blt_line = newl; Line(blt_line) = {blm_point, blt_point};
flt_line = newl; Line(flt_line) = {flt_point, flm_point};
flb_line = newl; Line(flb_line) = {flm_point, flb_point};
// Surfaces
b_lineloop = newll; Line Loop(b_lineloop) = {fb_line, rb_line, bb_line,
lb_line};
b_surface = news; Plane Surface(b_surface) = {b_lineloop};
m_lineloop = newll; Line Loop(m_lineloop) = {fm_line, rm_line, bm_line,
lm_line};
m_surface = news; Plane Surface(m_surface) = {m_lineloop};
t_lineloop = newll; Line Loop(t_lineloop) = {rt_line, bt_line, lt_line,
ft_line};
t_surface = news; Plane Surface(t_surface) = {t_lineloop};
fb_lineloop = newll; Line Loop(fb_lineloop) = {frb_line, -fb_line,
-flb_line, fm_line};
fb_surface = news; Plane Surface(fb_surface) = {fb_lineloop};
ft_lineloop = newll; Line Loop(ft_lineloop) = {frt_line, -fm_line,
-flt_line, ft_line};
ft_surface = news; Plane Surface(ft_surface) = {ft_lineloop};
bb_lineloop = newll; Line Loop(bb_lineloop) = {brb_line, bm_line, -blb_line,
-bb_line};
bb_surface = news; Plane Surface(bb_surface) = {bb_lineloop};
bt_lineloop = newll; Line Loop(bt_lineloop) = {brt_line, bt_line, -blt_line,
-bm_line};
bt_surface = news; Plane Surface(bt_surface) = {bt_lineloop};
rb_lineloop = newll; Line Loop(rb_lineloop) = {rb_line, brb_line, -rm_line,
frb_line};
rb_surface = news; Plane Surface(rb_surface) = {rb_lineloop};
rt_lineloop = newll; Line Loop(rt_lineloop) = {frt_line, rm_line, brt_line,
-rt_line};
rt_surface = news; Plane Surface(rt_surface) = {rt_lineloop};
lb_lineloop = newll; Line Loop(lb_lineloop) = {flb_line, -lb_line, blb_line,
lm_line};
lb_surface = news; Plane Surface(lb_surface) = {lb_lineloop};
lt_lineloop = newll; Line Loop(lt_lineloop) = {flt_line, -lm_line, blt_line,
lt_line};
lt_surface = news; Plane Surface(lt_surface) = {lt_lineloop};
// Volumes
b_surfaceloop = newsl; Surface Loop(b_surfaceloop) = { b_surface, fb_surface,
bb_surface,
rb_surface, lb_surface,
m_surface};
b_volume = newv; Volume(b_volume) = {b_surfaceloop};
t_surfaceloop = newsl; Surface Loop(t_surfaceloop) = { m_surface, ft_surface,
bt_surface,
rt_surface, lt_surface,
t_surface};
t_volume = newv; Volume(t_volume) = {t_surfaceloop};
// Transfinite settings
Transfinite Line { rb_line} = 1/den Using Progression 1.;
Transfinite Line { bb_line} = 1/den Using Progression 1.;
Transfinite Line { lb_line} = 1/den Using Progression 1.;
Transfinite Line { fb_line} = 1/den Using Progression 1.;
Transfinite Line { rm_line} = 1/den Using Progression 1.;
Transfinite Line { bm_line} = 1/den Using Progression 1.;
Transfinite Line { lm_line} = 1/den Using Progression 1.;
Transfinite Line { fm_line} = 1/den Using Progression 1.;
Transfinite Line {frb_line} = 0.5/den Using Progression 1.;
Transfinite Line {brb_line} = 0.5/den Using Progression 1.;
Transfinite Line {blb_line} = 0.5/den Using Progression 1.;
Transfinite Line {flb_line} = 0.5/den Using Progression 1.;
Transfinite Line {frt_line} = 0.5/den Using Progression 1.;
Transfinite Line {brt_line} = 0.5/den Using Progression 1.;
Transfinite Line {blt_line} = 0.5/den Using Progression 1.;
Transfinite Line {flt_line} = 0.5/den Using Progression 1.;
Transfinite Line { rt_line} = 1/den Using Progression 1.;
Transfinite Line { bt_line} = 1/den Using Progression 1.;
Transfinite Line { lt_line} = 1/den Using Progression 1.;
Transfinite Line { ft_line} = 1/den Using Progression 1.;
If( top_structured == 1 )
If( alternate == 1 )
Transfinite Surface { t_surface} Alternate;
Transfinite Surface {ft_surface} Alternate;
Transfinite Surface {bt_surface} Alternate;
Transfinite Surface {rt_surface} Alternate;
Transfinite Surface {lt_surface} Alternate;
EndIf
If( alternate == 0 )
Transfinite Surface { t_surface};
Transfinite Surface {ft_surface};
Transfinite Surface {bt_surface};
Transfinite Surface {rt_surface};
Transfinite Surface {lt_surface};
EndIf
EndIf
If( bottom_structured == 1 )
If( alternate == 1 )
Transfinite Surface { b_surface} Alternate;
Transfinite Surface {fb_surface} Alternate;
Transfinite Surface {bb_surface} Alternate;
Transfinite Surface {rb_surface} Alternate;
Transfinite Surface {lb_surface} Alternate;
EndIf
If( alternate == 0 )
Transfinite Surface { b_surface};
Transfinite Surface {fb_surface};
Transfinite Surface {bb_surface};
Transfinite Surface {rb_surface};
Transfinite Surface {lb_surface};
EndIf
EndIf
If( top_structured == 1 || bottom_structured == 1 )
If( alternate == 1 )
Transfinite Surface {m_surface} Alternate;
EndIf
If( alternate == 0 )
Transfinite Surface {m_surface};
EndIf
EndIf
If( top_hex == 1 )
Recombine Surface {t_surface};
Recombine Surface {ft_surface};
Recombine Surface {bt_surface};
Recombine Surface {rt_surface};
Recombine Surface {lt_surface};
EndIf
If( bottom_hex == 1 )
Recombine Surface {b_surface};
Recombine Surface {fb_surface};
Recombine Surface {bb_surface};
Recombine Surface {rb_surface};
Recombine Surface {lb_surface};
EndIf
If( top_hex == 1 && bottom_hex == 1 )
Recombine Surface {m_surface};
EndIf
If( top_hex == 1 && bottom_hex == 0 )
TransfQuadTri {t_volume};
EndIf
If( top_hex == 0 && bottom_hex == 1 )
TransfQuadTri {b_volume};
EndIf
If( top_structured == 1 )
Transfinite Volume {t_volume} ;
EndIf
If( bottom_structured == 1 )
Transfinite Volume {b_volume} ;
EndIf
// Physical domains
Physical Surface("TopFace") = {t_surface};
Physical Surface("MiddleFace") = {m_surface};
Physical Surface("BottomFace") = {b_surface};
Physical Surface("UpperLeftFace") = {lt_surface};
Physical Surface("LowerLeftFace") = {lb_surface};
Physical Surface("UpperRightFace") = {rt_surface};
Physical Surface("LowerRightFace") = {rb_surface};
Physical Surface("UpperBackFace") = {bt_surface};
Physical Surface("LowerBackFace") = {bb_surface};
Physical Surface("UpperFrontFace") = {ft_surface};
Physical Surface("LowerFrontFace") = {fb_surface};
Physical Volume("TopVolume") = {t_volume};
Physical Volume("BottomVolume") = {b_volume};
_______________________________________________
gmsh mailing list
[email protected]
http://onelab.info/mailman/listinfo/gmsh
