Hello
Please find attached a patch to implement the AlternateLeft and AlternateRight
options in transfinite surfaces.
It would be apparently sufficient to change Gmsh.y and
Mesh/meshGFaceTransfinite.cpp, but I also updated the related comments in
Geo/GFace.h and Geo/Geo.h
The documentation needs updating (also one line?)
The geo files (with very imaginative names!) that I used for testing are
included. I also played with "demos/transfinite.geo", by not recombining and by
specifying the orientation and it seems to "do what is says".
Something else that I missed?
Regards
ZP
On Tuesday 09 July 2013, Christophe Geuzaine wrote:
> On 16 May 2013, at 18:40, Jose Paulo Moitinho de Almeida
<[email protected]> wrote:
> > I wanted to create a triangular Transfinite Surface mesh , but was not
> > able to control the position of the initial triangle created by gmsh
> > (the corners always have only element, as in 1.png).
> >
> > After looking at the code I swapped the logic in
> > Mesh/meshGFaceTransfinite.cpp from
> >
> > ((i % 2 == 0 && j % 2 == 1) ||
> >
> > (i % 2 == 1 && j % 2 == 0)))){
> >
> > to
> >
> > ((i % 2 == 0 && j % 2 == 0) ||
> >
> > (i % 2 == 1 && j % 2 == 1)))){
> >
> > and managed to obtain the result that I wanted (in 2.png).
> >
> > Is there an easier way to achieve this?
> >
> > If there isn't, it would not be too complicated to include an additional
> > option to Transfinite Surface, so that instead of "Left, Right and
> > Alternate" we could opt between "Left, Right AlternateLeft and
> > AlternateRight", with Alternate still legal and equivalent to the
> > current option.
> >
> > I should be able to propose a patch (not now...), but before I start
> > opinions are welcome.
>
> Hi Jose - That's a good idea: send a patch and I will merge it.
>
> > Regards
> >
> > ZP
> >
> > PS: I also considered the idea of adding an additional option, which
> > would create a mesh where both diagonals are always inserted, so that
> > using
> >
> > Transfinite Line{1,2,3,4} = 2;
> > Transfinite Surface {6} = {1, 2, 3, 4} "OtherNewOption";
> >
> > in the attached file, would result in 3.png.
> >
> > I understand that an additional set of vertices is needed, and this is
> > not so immediate. Would it be too complicated to include them in the
> > code?
> > <square.geo><1.png><2.png><3.png>_______________________________________
> > ________ gmsh mailing list
> > [email protected]
> > http://www.geuz.org/mailman/listinfo/gmsh
Index: Geo/GFace.h
===================================================================
--- Geo/GFace.h (revision 16163)
+++ Geo/GFace.h (working copy)
@@ -286,7 +286,7 @@
// corners of the transfinite interpolation
std::vector<GVertex*> corners;
// all diagonals of the triangulation are left (-1), right (1) or
- // alternated (0)
+ // alternated starting at right (2) or left (-2)
int transfiniteArrangement;
// do we smooth (transfinite) mesh? (<0 to use default smoothing)
int transfiniteSmoothing;
Index: Geo/Geo.h
===================================================================
--- Geo/Geo.h (revision 16163)
+++ Geo/Geo.h (working copy)
@@ -148,7 +148,7 @@
char Visible;
int Method;
int Recombine;
- int Recombine_Dir; // -1 is left, +1 is right, 0 is alternated
+ int Recombine_Dir; // -1 is left, +1 is right, -2/2 is alternated left/right
double RecombineAngle;
int TransfiniteSmoothing;
List_T *Generatrices;
Index: Parser/Gmsh.y
===================================================================
--- Parser/Gmsh.y (revision 16163)
+++ Parser/Gmsh.y (working copy)
@@ -3455,9 +3455,13 @@
if(!strcmp($1, "Right"))
$$ = 1;
else if(!strcmp($1, "Left"))
- $$ = -1;
- else // alternated
- $$ = 0;
+ $$ = -1;
+ else if(!strcmp($1, "AlternateRight"))
+ $$ = 2;
+ else if(!strcmp($1, "AlternateLeft"))
+ $$ = -2;
+ else // "Alternate" -> "Alternate Right"
+ $$ = 2;
Free($1);
}
;
Index: Mesh/meshGFaceTransfinite.cpp
===================================================================
--- Mesh/meshGFaceTransfinite.cpp (revision 16163)
+++ Mesh/meshGFaceTransfinite.cpp (working copy)
@@ -423,9 +423,13 @@
if(CTX::instance()->mesh.recombineAll || gf->meshAttributes.recombine)
gf->quadrangles.push_back(new MQuadrangle(v1, v2, v3, v4));
else if(gf->meshAttributes.transfiniteArrangement == 1 ||
- (gf->meshAttributes.transfiniteArrangement == 0 &&
+ (gf->meshAttributes.transfiniteArrangement == 2 &&
((i % 2 == 0 && j % 2 == 1) ||
- (i % 2 == 1 && j % 2 == 0)))){
+ (i % 2 == 1 && j % 2 == 0))) ||
+ (gf->meshAttributes.transfiniteArrangement == -2 &&
+ ((i % 2 == 0 && j % 2 == 0) ||
+ (i % 2 == 1 && j % 2 == 1)))
+ ){
gf->triangles.push_back(new MTriangle(v1, v2, v3));
gf->triangles.push_back(new MTriangle(v3, v4, v1));
}
@@ -452,9 +456,13 @@
if(CTX::instance()->mesh.recombineAll || gf->meshAttributes.recombine)
gf->quadrangles.push_back(new MQuadrangle(v1, v2, v3, v4));
else if(gf->meshAttributes.transfiniteArrangement == 1 ||
- (gf->meshAttributes.transfiniteArrangement == 0 &&
+ (gf->meshAttributes.transfiniteArrangement == 2 &&
((i % 2 == 0 && j % 2 == 1) ||
- (i % 2 == 1 && j % 2 == 0)))){
+ (i % 2 == 1 && j % 2 == 0))) ||
+ (gf->meshAttributes.transfiniteArrangement == -2 &&
+ ((i % 2 == 0 && j % 2 == 0) ||
+ (i % 2 == 1 && j % 2 == 1)))
+ ){
gf->triangles.push_back(new MTriangle(v1, v2, v3));
gf->triangles.push_back(new MTriangle(v3, v4, v1));
}
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Point(4) = {0, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(5) = {3, 4, 1, 2};
Plane Surface(6) = {5};
Transfinite Line{1,2,3,4} = 3;
Transfinite Surface {6} = {1, 2, 3, 4};
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Point(4) = {0, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(5) = {3, 4, 1, 2};
Plane Surface(6) = {5};
Transfinite Line{1,2,3,4} = 3;
Transfinite Surface {6} = {1, 2, 3, 4} AlternateLeft;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Point(4) = {0, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(5) = {3, 4, 1, 2};
Plane Surface(6) = {5};
Transfinite Line{1,2,3,4} = 3;
Transfinite Surface {6} = {1, 2, 3, 4} AlternateRight;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Point(4) = {0, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(5) = {3, 4, 1, 2};
Plane Surface(6) = {5};
Transfinite Line{1,2,3,4} = 3;
Transfinite Surface {6} = {1, 2, 3, 4} Left;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};},
Point(3) = {1, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 1};
Line Loop(5) = {1, 2, 3};
Plane Surface(6) = {5};
Transfinite Line{1,2,3} = 5;
Transfinite Surface {6} = {2, 3, 1};
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Point(4) = {0, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(5) = {3, 4, 1, 2};
Plane Surface(6) = {5};
Transfinite Line{1,2,3,4} = 3;
Transfinite Surface {6} = {1, 2, 3, 4} Right;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 1};
Line Loop(5) = {1, 2, 3};
Plane Surface(6) = {5};
Transfinite Line{1,2,3} = 5;
Transfinite Surface {6} = {2, 3, 1} AlternateLeft;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 1};
Line Loop(5) = {1, 2, 3};
Plane Surface(6) = {5};
Transfinite Line{1,2,3} = 5;
Transfinite Surface {6} = {2, 3, 1} AlternateRight;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 1};
Line Loop(5) = {1, 2, 3};
Plane Surface(6) = {5};
Transfinite Line{1,2,3} = 5;
Transfinite Surface {6} = {2, 3, 1} Left;
Point(1) = {0, 0, 0, 1};
Point(2) = {1, 0, 0, 1};
Point(3) = {1, 1, 0, 1};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 1};
Line Loop(5) = {1, 2, 3};
Plane Surface(6) = {5};
Transfinite Line{1,2,3} = 5;
Transfinite Surface {6} = {2, 3, 1} Right;
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