msh format $Entities: negative bounding point tags?
A quick question about $Entities
. This geo
Point(1) = {0, 0, 0, 1.0};
Point(2) = {1, 0, 0, 1.0};
Point(3) = {1, 1, 0, 1.0};
Point(4) = {0, 1, 0, 1.0};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop(1) = {1, 2, 3, 4};
Plane Surface(1) = {1};
Physical Curve("unten") = {1};
Physical Curve("rechts") = {2};
Physical Curve("oben") = {3};
Physical Curve("links") = {4};
Physical Surface("Einheitsquadrat") = {1};
gives a msh
with
$Entities
4 4 1 0
1 0 0 0 0
2 1 0 0 0
3 1 1 0 0
4 0 1 0 0
1 0 0 0 1 0 0 1 1 2 1 -2
2 1 0 0 1 1 0 1 2 2 2 -3
3 0 1 0 1 1 0 1 3 2 3 -4
4 0 0 0 0 1 0 1 4 2 4 -1
1 0 0 0 1 1 0 1 5 4 1 2 3 4
$EndEntities
The curves
section, contains negative values as bounding_points
. What's the significance of that?