Path: news.mathworks.com!not-for-mail From: "Ben " <gogo.xa@gmail.com> Newsgroups: comp.soft-sys.matlab Subject: Re: intersection of two surfaces Date: Wed, 17 Nov 2010 04:53:03 +0000 (UTC) Organization: Johns Hopkins University Lines: 24 Message-ID: <ibvn3f$f27$1@fred.mathworks.com> References: <ibcouk$kjg$1@fred.mathworks.com> <ibtg8k$a0a$1@fred.mathworks.com> <ibv3qk$end$1@fred.mathworks.com> <ibvhbq$9f4$1@fred.mathworks.com> <ibvkmj$bcm$1@fred.mathworks.com> <ibvl1s$3tf$1@fred.mathworks.com> <ibvls3$q33$1@fred.mathworks.com> Reply-To: "Ben " <gogo.xa@gmail.com> NNTP-Posting-Host: webapp-03-blr.mathworks.com Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Trace: fred.mathworks.com 1289969583 15431 172.30.248.38 (17 Nov 2010 04:53:03 GMT) X-Complaints-To: news@mathworks.com NNTP-Posting-Date: Wed, 17 Nov 2010 04:53:03 +0000 (UTC) X-Newsreader: MATLAB Central Newsreader 2452314 Xref: news.mathworks.com comp.soft-sys.matlab:687500 Hi Roger, Do you further know how to find the intersection of two surface represented using triangulated meshes? Or one surface is a triangulated mesh while another is a cylinder represented using its axis (a normalized vector), a point on the axis, and the radius? Thanks, Ben "Roger Stafford" <ellieandrogerxyzzy@mindspring.com.invalid> wrote in message <ibvls3$q33$1@fred.mathworks.com>... > "Ben " <gogo.xa@gmail.com> wrote in message <ibvl1s$3tf$1@fred.mathworks.com>... > > ....... > > What if the plane is represented using a normal and a point on it? Thank you. > > ....... > - - - - - - - - - > If P0 is the point on the plane and N a normal to the plane. Then the equation of the plane is dot(P-P0,N) = 0. Or expressed in separate coordinates: > > nx*x + ny*y + nz*z - (nx*x0+ny*y0+nz*z0) = 0. > > where P0 = [x0,y0,z0] and N = [nx,ny,nz]. > > To use this to find your "middle" plane you need to use an N which is normalized. Do this: > > N = N/norm(N); > > Roger Stafford