From: Marco O Lanzagorta (lnzgrt++at++cmf.nrl.navy.mil)
Date: 11/07/2001 07:24:18
Hello,
I am working on a similar problem, I have Level 1 DTED data (~100m) for
the entire US, and high resolution images (~1m) for a few cities. I have
been using pfASDs for the terrain and cliptextures for the imagery. Right
now I have been able to generate ASDs from the DTED and place non-virtual
cliptextures on top. It looks very good, and in our Onyx 3400 works very
smooth.
However, (1) I still have not been able to place a virtual cliptexture
on the ASD as one of the pfASD functions dumps core with no reason, and
(2) I am still struggling to deform the ASD to make it fit the Earth
geometry (my ASDs correspond to a flat Earth).
I had to learn these topics the hard way, by studying the SGI src code
provided in the distribution, and reading the developers manual.
Marco
===========================================================================
Dr. Marco Lanzagorta email: lnzgrt++at++volt.nrl.navy.mil
Code 5594 phone: (202) 767-8427
Center for Computational Science fax : (202) 404-7402
Naval Research Laboratory
4555 Overlook Ave, S.W.
Washington, DC 20375 http://ohm.nrl.navy.mil/staff/lnzgrt
===========================================================================
On Wed, 7 Nov 2001, Paul Brewster wrote:
> I'm beginning to work on an application that uses satellite data to
> generate terrain data with camera images texture mapped onto it. I can
> straight-forward generate geodes, geosets, and geostates to handle this,
> but this obvious problem is that the data set is very large and will not
> fit into memory.
>
> I know this is a well-known problem with various solutions to it, and I
> just don't know these solutions. pfASD's and clip textures look to be
> the Performer answer to this. Is this correct? Other than reading man
> pages and looking at source code, is there an easy way to learn this?
> Are there other methods out there?
>
> What I'm thinking is that this is something that has been done many many
> times. By now there should be a simple plug-away answer to this.
>
>
> I had another quick question. I thought I saw that Performer 2.4
> supports multi-texturing. I assume this means that I can map several
> textures to the same geometry. Is this supported on IR2 and IR3
> machines?
>
> Thanks for any help.
>
> Paul Brewster
> Data Visualization and Analysis Lab
> NASA Langley Research Center
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