Can gmsh subdivide triangular prisms of similar width and height

Question

Dear All

I am looking for a way to
mesh a spherical shell in such a way, that initially
it is subdivided into layers that can be cut into triangular prisms
by connecting the corresponding points in the triangulations between layers and
then subdivide the resulting triangular prisms in 3 tets, assuming, that
the layer thickness is chosen roughly the same as the triangle size
and slowly increased etc.

regards

Moritz

Comments

I'm not sure what you mean, but does this help?

// modified transfinite.geo demo file from gmsh

l = 1;
r1 = 2;
r2 = 0.5;
n = 10;
n2 = n;
progr = 1.2;


Point(1) = {0,0,0,l};

// exterior sphere
Point(2) = {r1,r1,-r1,l};
Point(3) = {-r1,r1,-r1,l};
Point(4) = {-r1,-r1,-r1,l};
Point(5) = {r1,-r1,-r1,l};
Circle(1) = {3,1,2};
Circle(2) = {2,1,5};
Circle(3) = {5,1,4};
Circle(4) = {4,1,3};
Line Loop(5) = {1,2,3,4};
Ruled Surface(6) = {5};
Rotate { {1,0,0},{0,0,0}, Pi/2 } { Duplicata{ Surface{6}; } }
Rotate { {1,0,0},{0,0,0}, Pi } { Duplicata{ Surface{6}; } }
Rotate { {1,0,0},{0,0,0}, 3*Pi/2 } { Duplicata{ Surface{6}; } }
Rotate { {0,1,0},{0,0,0}, Pi/2 } { Duplicata { Surface{6}; } }
Rotate { {0,1,0},{0,0,0}, -Pi/2 } { Duplicata { Surface{6}; } }


// interior sphere
Point(102) = {r2,r2,-r2,l};
Point(103) = {-r2,r2,-r2,l};
Point(104) = {-r2,-r2,-r2,l};
Point(105) = {r2,-r2,-r2,l};
Circle(29) = {103,1,102};
Circle(30) = {102,1,105};
Circle(31) = {105,1,104};
Circle(32) = {104,1,103};
Line Loop(33) = {29,30,31,32};
Ruled Surface(34) = {33};
Rotate { {1,0,0},{0,0,0}, Pi/2 } { Duplicata{ Surface{34}; } }
Rotate { {1,0,0},{0,0,0}, Pi } { Duplicata{ Surface{34}; } }
Rotate { {1,0,0},{0,0,0}, 3*Pi/2 } { Duplicata{ Surface{34}; } }
Rotate { {0,1,0},{0,0,0}, Pi/2 } { Duplicata { Surface{34}; } }
Rotate { {0,1,0},{0,0,0}, -Pi/2 } { Duplicata { Surface{34}; } }

// connect spheres
Line(52) = {102,2};
Line(53) = {108,8};
Line(54) = {105,5};
Line(55) = {111,11};
Line(56) = {109,9};
Line(57) = {104,4};
Line(58) = {103,3};
Line(59) = {106,6};

Line Loop(60) = {58,1,-52,-29};Plane Surface(61) = {60};
Line Loop(62) = {58,11,-59,-39};Plane Surface(63) = {62};
Line Loop(64) = {59,8,-53,-36};Plane Surface(65) = {64};
Line Loop(66) = {37,52,-9,-53};Plane Surface(67) = {66};
Line Loop(68) = {56, 21,-57,-49};Plane Surface(69) = {68};
Line Loop(70) = {31,57,-3,-54};Plane Surface(71) = {70};
Line Loop(72) = {54,19,-55,-47};Plane Surface(73) = {72};
Line Loop(74) = {55,-13,-56,41};Plane Surface(75) = {74};
Line Loop(76) = {59,16,-56,-44};Plane Surface(77) = {76};
Line Loop(78) = {58,-4,-57,32};Plane Surface(79) = {78};
Line Loop(80) = {52,2,-54,-30};Plane Surface(81) = {80};
Line Loop(82) = {42,53,-14,-55};Plane Surface(83) = {82};

// connection volumes
Surface Loop(84) = {7,61,-63,-65,67,-35}; Volume(85) = {84};
Surface Loop(86) = {34,61,-79,6,81,-71}; Volume(87) = {86};
Surface Loop(88) = {22,-79,63,77,69,-50}; Volume(89) = {88};
Surface Loop(90) = {12,83,-40,75,-77,65}; Volume(91) = {90};
Surface Loop(92) = {23,81,-67,-51,-83,73}; Volume(93) = {92};
Surface Loop(94) = {17,-71,-45,-73,-75,-69}; Volume(95) = {94};

// define transfinite mesh
Transfinite Line {53, 59, 52, 58, 55, 56, 54, 57} = n Using Progression progr;
Transfinite Line {1, 2, 3, 4, 9, 11,8,16,14,13,19,21,
                  41,42,44,36,39,37, 29, 30,32, 49,31,47} = n2;



Transfinite Surface "*";
// Recombine Surface "*";
Transfinite Volume "*";