# Exception when trying to fuse two through-sections

Hello.

I get an exception when trying to fuse two through-sections as shown in the examplecode below. Can anyone see a reason why this does not work? Does anyone know how robust the boolean operation are, (i.e. cut and fuse)?

double bottomPoints1[12] = { 20, -10, 0, 7100, -10, 0, 7100, -1190, 0, 20, -1190, 0};

double topPoints1[12] = { 10, 0, 10, 7100, 0, 10, 7100, -1200, 10, 10, -1200, 10};

double bottomPoints2[12] = { 10, 0, 10, 7100, 0, 10, 7100, -1200, 10, 10, -1200, 10};

double topPoints2[12] = { 10, 0, 25, 7100, 0, 25, 7100, -1200, 25, 10, -1200, 25};

BRepBuilderAPI_MakePolygon bottomPolygon1, topPolygon1, bottomPolygon2, topPolygon2;

gp_Pnt tmpPnt;

for (int i=0;i

{

tmpPnt.SetCoord(bottomPoints1[3*i], bottomPoints1[3*i+1], bottomPoints1[3*i+2]);

tmpPnt.SetCoord(topPoints1[3*i], topPoints1[3*i+1], topPoints1[3*i+2]);

tmpPnt.SetCoord(bottomPoints2[3*i], bottomPoints2[3*i+1], bottomPoints2[3*i+2]);

tmpPnt.SetCoord(topPoints2[3*i], topPoints2[3*i+1], topPoints2[3*i+2]);

}

bottomPolygon1.Close();

topPolygon1.Close();

bottomPolygon2.Close();

topPolygon2.Close();

BRepOffsetAPI_ThruSections loft1(Standard_True, Standard_True);

loft1.Build();

BRepOffsetAPI_ThruSections loft2(Standard_True, Standard_True);