<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><blockquote type="cite"></blockquote>Hello,</div><div><br></div><div>you may try to first project the velocity vector on the surface, so that the normal components are zero, then compute the streamlines using this velocity field. I did this with a velocity field which was defined as a cell data, and the results are good (at least in my case...).</div><div><br></div><div>Regards,</div><div>-Marzio</div><div><br><br><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; font-size:medium; color:rgba(0, 0, 0, 0.5);"><b>From: </b></span><span style="font-family:'Helvetica'; font-size:medium;">Richard GRENON <<a href="mailto:richard.grenon@onera.fr">richard.grenon@onera.fr</a>><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; font-size:medium; color:rgba(0, 0, 0, 0.5);"><b>Date: </b></span><span style="font-family:'Helvetica'; font-size:medium;">April 10, 2009 11:35:46 AM GMT+02:00<br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; font-size:medium; color:rgba(0, 0, 0, 0.5);"><b>To: </b></span><span style="font-family:'Helvetica'; font-size:medium;">Jacques Papper <<a href="mailto:jacques.papper@gmail.com">jacques.papper@gmail.com</a>><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; font-size:medium; color:rgba(0, 0, 0, 0.5);"><b>Cc: </b></span><span style="font-family:'Helvetica'; font-size:medium;"><a href="mailto:paraview@paraview.org">paraview@paraview.org</a><br></span></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px;"><span style="font-family:'Helvetica'; font-size:medium; color:rgba(0, 0, 0, 0.5);"><b>Subject: </b></span><span style="font-family:'Helvetica'; font-size:medium;"><b>Re: [Paraview] How to plot Surface StreamLines</b><br></span></div><br><br>Jacques Papper wrote:<br><blockquote type="cite">I would try :<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">- diminishing the step size (in cell length)<br></blockquote><blockquote type="cite">- Putting a very high number of steps<br></blockquote><blockquote type="cite">- Decreasing the termination speed<br></blockquote><blockquote type="cite"><br></blockquote>I tried this. The best results are obtained with a step size of 0.01 cell length on my data,and I get always short peaces of surface streamlines.<br>I discovered that the grid refinement was also an important parameter:<br>- when the grid is coarse at the seed point location, the surface streamline stops after crossing only one or two cells.<br>- when the grid is well refined at the seed point location, the surface streamline is longer and propagates over many cells, but it never reaches the boundary of the surface.<br><br>So I think that the best workaround is to put many seed points all over the surface. If someone has a better idea...<br><br>Best regards.<br><br>-- <br>Richard GRENON<br>ONERA<br>Departement d'Aerodynamique Appliquee - DAAP/ACI<br>8 rue des Vertugadins<br>92190 MEUDON - FRANCE<br>phone : +33 1 46 73 42 17<br>fax : +33 1 46 73 41 46<br><a href="mailto:Richard.Grenon@onera.fr">mailto:Richard.Grenon@onera.fr</a><br>http://www.onera.fr</blockquote></div></body></html>