On Wed, Nov 21, 2012 at 6:16 AM, Andrew Parker <span dir="ltr"><<a href="mailto:andy.john.parker@googlemail.com" target="_blank">andy.john.parker@googlemail.com</a>></span> wrote:<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
ation of t</blockquote></div><div><br></div>For line/mesh intersection I use vtkModifiedBSPTree:<div><br><div><a href="http://www.vtk.org/Wiki/VTK/Examples/Cxx/DataStructures/ModifiedBSPTree_IntersectWithLine">http://www.vtk.org/Wiki/VTK/Examples/Cxx/DataStructures/ModifiedBSPTree_IntersectWithLine</a><br clear="all">
<br>The way all of these line intersection algorithms works is that they actually intersect a finite line with the mesh. The 't' that gets returned is the relative distance along that line, so if the intersection occurs half way between the end points of the line segment, t would be 0.5. A t>1 seems to indicate that the length of the line segment you choose is too short, so that the line segment doesn't actually intersect the mesh between it's end points.<br>
<br>David<br></div></div>