[GRASS-user] Setting view location in nviz --- problems reloading 3d state

[Tom Russo]

I have a need for producing 3d renderings of a scene from a specific location
(for a class on map reading and compass use I'm teaching in two weeks), and
am having a little trouble managing nviz.  Ages ago I could do what I wanted
with d.3d or something like that, but that module is considered obsoleted by
nviz.  I've always had problems positioning the "puck" precisely in nviz and
would like to give the exact coordinates of my desired view point instead.

nviz has a "save 3d state" option that looks like it might do the trick, since
I could simply set my view point by editing a state file by hand.  However
when I try to reload a 3d state file (even one that's unedited) I get an 
error from nviz.  Attached is the log file.  After reading in the state file
I *do* get the image from the desired view point, but the position panel is
messed up --- the position "puck" is no longer available.  This is not a 
show-stopper since I do indeed get the rendering from the 3d state as specified
in the state file (which is all I need at the moment), but it would be nice if 
I could use the restored 3d state as a starting point for further manipulation 
as well as for restoring a static scene.

To reproduce:  load an elevation and color map into nviz, choose "Save 3d state"
then try to read the file back in.  

Anyone seen this before?  

And while I'm asking, does anyone have any hints and kinks for producing 
renderings of 3d scenes as viewed from precisely specified locations?  My
idea for what I want is to show topographic maps overlaid on the elevation
model for the area around the class location for folks to use to get a feel for
how contour lines translate into the real world around them, and want the 
rendering to look as close to what they'll see from the parking lot outside
the classroom as possible.

-- 
Tom Russo    KM5VY   SAR502   DM64ux          http://www.swcp.com/~russo/
Tijeras, NM  QRPL#1592 K2#398  SOC#236 AHTB#1 http://kevan.org/brain.cgi?DDTNM
"And, isn't sanity really just a one-trick pony anyway? I mean all you get is
 one trick, rational thinking, but when you're good and crazy, oooh, oooh,
 oooh, the sky is the limit!"  --- The Tick
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bad window path name ".middle.panelarea.panels.main.midf.pos"
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