HI Paul, VPB is built around working on earth data, hence the default to WGS84. You can override the size of the spheriod via --radius-equator value and --radius-polar value, a recent bug fix to VPB fixed this functionality so it should work now. It should also be possible to set the coordinate string for the output, but... I have to admit I haven't tested anything other than earth based data - to start I only have had earth data to work with so far and it's been the focus of the work.
As for non the coordinate system the data is in causing problems, again I've never had such data before so can't really provide any guidance on whether GDAL can cope with it. VPB should be able to handle what you after, but there is good chance that we'll need to tweak it a bit to achieve it. What bits we need to tweak I can't say off hand as.. again I have no experience with this type of data. Would it be possible for you to post an example dataset and the VPB options that you are using? Robert. On Thu, May 29, 2008 at 9:59 PM, Paul Brewster <[EMAIL PROTECTED]> wrote: > Hey all, > > I have a couple questions about VPB. I've been playing around with it for > about a month now, and have reached as far as I can go. After some help > from here a month ago (thanks all) I spent some time digging through the > source code to see what I could find and have reached about as far as I can > go by myself. It appears that I am trying to do something that VPB does not > support yet. I was hoping I could find a simple change to do what I want, > but it doesn't appear to be that easy. Or at least, my mind couldn't get > around the code enough to figure it out. Anyway, here are my > questions/concerns: > > 1) I am trying to do a model of the Moon. I have data in PDS format that > reads into GDAL just fine. I can run osgdem -l 1 -d foo.pds -o bar.ive and > it works fine. If I peek at the resulting ive file, I can see it has a > CoordinateSystemNode at the top with the right WKT in it. There is no > Ellipsoid because the terrain is flat. And a quick look at the vertices > seem to put them in the right area (uses moon radius, not Earth radius). > But I really need to do a spherical model of the Moon, since I am doing > Lander simulations and things like that matter. The only way I know to make > a spherical terrain is to use the "--geocentric" command. After tracing all > over the code, it appears that this forces VPB to use the WGS84 coordinate > system, no matter what else I try. When the intermediate and destination > coordinate systems are created, it automatically creates the default WGS84 > coordinate system with appropriate Ellipsoids, no matter what the input data > is. So no matter how I try, I always get an Earth-like Ellipsoid with WGS84 > coordinate system in my output. Am I doing something wrong? Is there a > command-line to indicate what I want the final coordinate system to be? I > have a WKT for the moon. Is there a way to force that? I tried entering > that WKT in, but it was never used for creating the intermediate and > destination data sets. > > 2) My data is in a Polar Stereographic projection, rather than a > cylindrical type projection. Which means that the center of the image is > the North (or South) Pole. Lat lines radially extend from the center and > Lon-lines are concentric rings around the center. When I use this on for a > "--geocentric" data set, it shows up as a partial "wedge" or "orange slice" > from the north pole to about 75 degrees North. It appears to me that it is > being treated like a cylindrical projection. I have not looked into this > problem as much. Is this a GDAL issue? Where does the projection from a > given pixel to a Lat-Lon happen? > > Anyway, thanks for the help. VPB is a pretty amazing piece of software. > I've been able to do huge datasets quickly and easily, so I'm really > excited to get it working on the Moon too. I appreciate any help. > > Paul Brewster > Data Visualization and Analysis Lab > NASA Langley Research Center > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
