Re: [Algorithms] Rendering (a portion of) a Plane
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From: Anceschi M. <anc...@li...> - 2000-07-21 19:44:38
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----- Original Message ----- From: "Steve Wood" <Ste...@im...> To: <gda...@li...> Sent: Friday, July 21, 2000 9:25 PM Subject: RE: [Algorithms] Rendering (a portion of) a Plane > Hmm, > > Your equation: > Normal[0] * X + Normal[1] * y + Normal[2] * z + distance = 0 > > is defining 3D space as an infinite number of parallel planes with the same > Normal as in the equation: > Normal[0] * X + Normal[1] * y + Normal[2] * z = 0 > > using an index of distance to determine which parallel plane you are > referencing. > Normal[0] * X + Normal[1] * y + Normal[2] * z = -distance > > Correct me if I'm wrong, but it sounds like you want to find points ON the > plane...if you are trying to describe a circle on the plane then you want > all points (x,y,z) which lie on the plane and which are the same distance > from your point of origin (x',y',z'). If you like matrices and > transformations then perhaps use the 2D (x,y) coordinate plane to find your > points x^2 + y^2 = distance, then translate and rotate them onto your plane. > > R&R > > > > -----Original Message----- > > From: Jeremy Bake [mailto:Jer...@in...] > > Sent: Friday, July 21, 2000 6:57 AM > > To: 'gda...@li...' > > Subject: [Algorithms] Rendering (a portion of) a Plane > > > > > > I've been working on my viewport culling and I just wanted to > > test something > > out > > I was wondering if anyone could tell me how to render a > > portion of a plane > > around > > a particular point using the > > Normal + distance version of a plane. > > I think it relates to > > Normal[0] * X + Normal[1] * y + Normal[2] * z + distance = 0 > > but I can't seem to get my head around how I could draw this function > > over a specific range... any help would be Greatly appreciated > > > > Jeremy Bake > > RtroActiv > > > > _______________________________________________ > > GDAlgorithms-list mailing list > > GDA...@li... > > http://lists.sourceforge.net/mailman/listinfo/gdalgorithms-list > > > > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > http://lists.sourceforge.net/mailman/listinfo/gdalgorithms-list thanks!!!!!!! mauro |