Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!mit-eddie!bbn.com!nic!bunny!harvey.gte.com!sg04
From: sg04@harvey.gte.com (Steven Gutfreund)
Newsgroups: comp.graphics.visualization
Subject: Re: Help: Creating 3-D mesh from arbitrary points.
Message-ID: <10636@bunny.GTE.COM>
Date: 20 Feb 91 15:15:38 GMT
References: <1991Feb14.190639.26922@lynx.CS.ORST.EDU> <1991Feb19.172446.15002@Arco.COM>
Sender: news@gte.com
Reply-To: sgutfreund@gte.com
Organization: GTE Laboratories, Waltham MA
Lines: 39

> In article <1991Feb14.190639.26922@lynx.CS.ORST.EDU> johng@OCE.ORST.EDU (John
> A. Gregor) writes:
> >We have a relatively large (several thousand) set of ocean samples in
> >3-D that we want to visualize.  Unfortunately, all the tools we have
> >demand that the data be represented as gridded data or as a connected
> >mesh (either tetrahedrons xor hexahedrons).  Any pointers to routines
> >or literature to accomplish this would be greatly appreciated.
> >
> >Some more notes about the data:  It's scattered in XY but linear in Z.
> >Also, the number of and distance between Z samples varies among the XY
> >locations.

I use the UNIRAS package for these sorts of operations. It it is
especially good for GIS applications, where one has a lot of
randomly placed 3D samples and one needs a grid. It is produced
by European Software Contractors A/S 376, Gladsaxevej
DK-2860 Soborg Denmark Phone +45 1 67 22 88.

They have a very fancy package, and routines I just don't
have the time to write myself. 

1. A weighted moving averages technique with smoothing, and
   correction based on surrounding gradients (good for large
   data sets)

2. A Triangularization based approach

3. A fit of 5th order spline surface patch

4. Kringing (a statistical based approach) and highly valued
   by GIS types. Good for maintaining small intermittent features.
   A pretty sophisticated algorithm (ie. don't try and implement
   it yourself in a day).

-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Yechezkal Shimon Gutfreund		 		  sgutfreund@gte.com
GTE Laboratories, Waltham MA			    harvard!bunny!sgutfreund
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=