Path: news.mathworks.com!not-for-mail From: <HIDDEN> Newsgroups: comp.soft-sys.matlab Subject: Re: Intersection of two 3D parametric curves Date: Thu, 29 Jan 2009 18:44:01 +0000 (UTC) Organization: The MathWorks, Inc. Lines: 9 Message-ID: <glstdh$l3c$1@fred.mathworks.com> References: <2496799.1170447574627.JavaMail.jakarta@nitrogen.mathforum.org> <ioOwh.33$FX6.13@newsfe02.lga> <glsr2n$nmt$1@fred.mathworks.com> Reply-To: <HIDDEN> NNTP-Posting-Host: webapp-05-blr.mathworks.com Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1233254641 21612 172.30.248.35 (29 Jan 2009 18:44:01 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Thu, 29 Jan 2009 18:44:01 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 1187260 Xref: news.mathworks.com comp.soft-sys.matlab:514786 "dfd invl" <73213@mt2009.com> wrote in message <glsr2n$nmt$1@fred.mathworks.com>... > ..... > Hmm I to having similar problem. > ..... Perhaps one way to simplify this problem is to realize that any three-dimensional intersection of the two parametric curves also represents an intersection of the projection of the curves on, say, the x-y plane. Therefore all you have to do is find all the x-y plane intersections and check each one to see if the two corresponding z values are equal. This should work whether the problem is being done analytically or numerically. Of course if there are points of the curve that are oriented orthogonally to the x-y plane, there could be difficulties there. Roger Stafford