Discussion Forum

I wonder if anyone has come across an apparent bug in the geomcsg function (COMSOL with MATLAB). I have a geometry where there is a flat box shape that is touching the bottom of several cylinders placed randomly on its surface. The "stx" cell array resulting from the call to geomcsg is supposed to have the subdomain/geometry association information. However, in many cases (different placements of the cylinders, but always just touching the surface of the box), I get the stx structure for the box telling me that it includes all subdomains in the geometry (second column of stx is all ones, except for first element). This is clearly not the case since there are no intersection subdomains.. What is strange is that this phenomenon disappears for some other random placements of the cylinders on the box !! I am sure that the geometries are not intersecting because even in the resulting stx structure, the number of geometries is equal to the number of subdomains !

I tried getting around the problem by elevating the cylinders just a very small amount from the surface of the box, but then I run into some unknown meshing issues !! Did any of you come across this bug ?