<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1515985973529_4214"> Hello Gmsh-Team:</div><div id="yui_3_16_0_ym19_1_1515985973529_4249"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4215">I am trying to mesh a volume with a hole in it. The outer surface-loop is<br id="yui_3_16_0_ym19_1_1515985973529_4216">a box built using OpenCascade and the inner 'hole' is a surface-loop from an stl file (see attachment 1).</div><div id="yui_3_16_0_ym19_1_1515985973529_4248"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4217">The geo script is given by:</div><div id="yui_3_16_0_ym19_1_1515985973529_4247"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4218">###### begin script ######</div><div id="yui_3_16_0_ym19_1_1515985973529_4219">Merge "merge_vtk_test_vein_test_vol.stl";</div><div id="yui_3_16_0_ym19_1_1515985973529_4220">SetFactory("OpenCASCADE");<br id="yui_3_16_0_ym19_1_1515985973529_4221">Box(2) = {10, 10, 20, 35, 30, 20};<br id="yui_3_16_0_ym19_1_1515985973529_4222">//+<br id="yui_3_16_0_ym19_1_1515985973529_4223">Surface Loop(2) = {6, 2, 4, 3, 7, 5}; // box surface-loop<br id="yui_3_16_0_ym19_1_1515985973529_4224">//+<br id="yui_3_16_0_ym19_1_1515985973529_4225">Surface Loop(3) = {1}; // stl object surface-loop<br id="yui_3_16_0_ym19_1_1515985973529_4226">//+<br id="yui_3_16_0_ym19_1_1515985973529_4227">Volume(3) = {2, 3};</div><div id="yui_3_16_0_ym19_1_1515985973529_4228">###### end script ########</div><div id="yui_3_16_0_ym19_1_1515985973529_4250"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4229">The commands following the Box command (comments mine) were generated using the Geom..->Elem..Ent..->Add->Volume <br id="yui_3_16_0_ym19_1_1515985973529_4230">tool using the box as the outer surface-loop and the stl object as the inner surface-loop.</div><div id="yui_3_16_0_ym19_1_1515985973529_4251"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4231">When I try to mesh this volume in 3D (Mesh->Define->3D) it only meshes the volume of the outer <br id="yui_3_16_0_ym19_1_1515985973529_4232">surface-loop and ignores the inner 'stl based' surface loop. Verified using clipping tool.</div><div id="yui_3_16_0_ym19_1_1515985973529_4252"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4233">I have tried this with two extruded boxes and can get it to work fine (see attachment 2).<br id="yui_3_16_0_ym19_1_1515985973529_4234"> <br id="yui_3_16_0_ym19_1_1515985973529_4235">Also, if I just load the stl file and build a volume (using only the stl surface with no holes) the interior<br id="yui_3_16_0_ym19_1_1515985973529_4236">of this stl volume is meshed with 3d tets. The problem seems to be related to the use of the stl surface as a hole.<br id="yui_3_16_0_ym19_1_1515985973529_4237"> </div><div id="yui_3_16_0_ym19_1_1515985973529_4238">I am using gmsh version 3.0.5.</div><div id="yui_3_16_0_ym19_1_1515985973529_5078"><br></div><div id="yui_3_16_0_ym19_1_1515985973529_4239" dir="ltr">Cheers<br id="yui_3_16_0_ym19_1_1515985973529_4240">Tony M.</div></div></body></html>