the famous "piece.geo" with an explicit volume definition (netgen test)

benchmarks/3d/piece_explicit_volume.geo

+
+r1 = .1;
+l1 = 1.;
+l2 = .8;
+l3 = .1;
+r2 = 1.1;
+lc = .1;
+lc2 = .05;
+rint = .2;
+rext = .3;
+
+Point(1) = {0.0,0.0,0.0,lc};
+Point(2) = {l1,0.0,0.0,lc2};
+Point(3) = {l1-r1,0.0,0.0,lc2};
+Point(4) = {l1,r1,0.0,lc2};
+Point(5) = {l1,-r1,0.0,lc2};
+Point(6) = {l1+l2,r1,0.0,lc};
+Point(7) = {l1+l2,-r1,0.0,lc};
+Point(8) = {l1+l2,-r1-l3,0.0,lc};
+Point(9) = {l1+l2,r1+l3,0.0,lc};
+
+Line(1) = {4,6};
+Line(2) = {6,9};
+Line(3) = {7,8};
+Line(4) = {5,7};
+Circle(5) = {4,2,3};
+Circle(6) = {3,2,5};
+
+r = 2*3.14159/5;
+Point(10) = { (l1 + r2) * Cos(r/2) , (l1 + r2) * Sin(r/2), 0.0, lc};
+
+// Remember, all rotations are specified by the axis direction
+// ({0,0,1}), an axis point ({0,0,0}) and a rotation angle (r)
+
+i = 0 ;
+
+For(1:4)
+
+  i+=1 ; 
+
+  Rotate {{0.0,0.0,1.0},{0.0,0.0,0.0}, i*r} {
+    Duplicata {
+      Line{1}; Line{2}; Line{3}; 
+      Line{4}; Line{5}; Line{6}; 
+      Point{10};
+    }
+  }
+
+EndFor
+
+Point(newp) = {rint,0,0,lc};
+Point(newp) = {rext,0,0,lc};
+Point(newp) = {-rint,0,0,lc};
+Point(newp) = {-rext,0,0,lc};
+Point(newp) = {0,rint,0,lc};
+Point(newp) = {0,rext,0,lc};
+Point(newp) = {0,-rint,0,lc};
+Point(newp) = {0,-rext,0,lc};
+
+Circle(31) = {8,118,97};
+Circle(32) = {20,10,9};
+Circle(33) = {47,37,16};
+Circle(34) = {74,64,43};
+Circle(35) = {101,91,70};
+Circle(36) = {119,1,123};
+Circle(37) = {123,1,121};
+Circle(38) = {121,1,125};
+Circle(39) = {125,1,119};
+Circle(40) = {124,1,122};
+Circle(41) = {122,1,126};
+Circle(42) = {126,1,120};
+Circle(43) = {120,1,124};
+
+Line Loop(44) = {37,38,39,36};
+Line Loop(46) = {40,41,42,43};
+Plane Surface(47) = {46,44};
+
+Line Loop(48) = -{-2,-1,5,6,4,3,31,-26,-25,29,30,28,27,35,-20,-19,
+  23,24,22,21,34,-14,-13,17,18,16,15,33,-8,-7,11,12,10,9,32};
+Plane Surface(49) = {48,46};
+
+Extrude Surface {47, {0,0,0.2}};
+Extrude Surface {49, {0,0,0.2}};
+Extrude Surface {91, {0,0,0.2}};
+Extrude Surface {47, {0,0,-0.2}};
+
+Delete { Volume{1:4}; }
+
+Surface Loop(373) = {288,135,-49,139,143,147,151,155,159,163,167,171,175,179,183,187,191,195,199,203,207,211,215,219,223,227,231,235,239,243,247,251,255,259,263,267,271,-355,-343,-347,-351,-372,-359,78,82,-363,-367,86,90,-371,329,317,321,325,330,301,305,309,313};
+Volume(374) = {373};