> With such a wide range of marking out areas, including gas density, > time-lapse for dissipation, etc, why would you define your new world > as "triangles all the way down"?
triangular boundaries are the minimum necessary to define area. I agree it can be said a measurement is taken somewhere within a triangular area - but the recursive level can approximate the precision of the measuring instrument. it's not intended for the triangle defined by the measurement to reflect the shape of what's within it - but it and adjacent triangles along a path can hold a "Main Street" or perhaps a "12 ppb benzene" attribute. - brian > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of stephen white > Sent: Monday, June 18, 2007 10:47 AM > To: [email protected] > Subject: Re: [Geowanking] RE: New coding schemes - geospatial metadata > > > On 18/06/2007, at 11:56 PM, brian grant wrote: > > correct but a hierarchical scheme originating from a recursive > > function can > > be very database friendly, open and easy to understand. > > I don't really agree... the recursive function defines a fixed shape > like triangles or octagons, and you can say that your data point is > somewhere inside this shape which is about that size by the depth in > the recursion. > > You couldn't use it to define an irregular smear or vague areas > defined more or less at random. Think of pizza delivery areas where > the range of coverage is defined by the roads in the area rather than > a circle around the shop. > > Bezier curves are more useful for that kind of outlining, but also > suffers from hard-edging ... it's sometimes more useful to define > shapes by gradient rather than contours, so even algorithms like > OpenGL lighting with surface normals can be more appropriate. > > With such a wide range of marking out areas, including gas density, > time-lapse for dissipation, etc, why would you define your new world > as "triangles all the way down"? > > -- > [EMAIL PROTECTED] > > > _______________________________________________ > Geowanking mailing list > [email protected] > http://lists.burri.to/mailman/listinfo/geowanking > _______________________________________________ Geowanking mailing list [email protected] http://lists.burri.to/mailman/listinfo/geowanking
