Hi all, I am trying to use NVIZ and am having a hard time getting a nice bird's
eye view. The "top" button centers the image nicely, however north generally
points left diagonally (or some other random direction). Is there anyway to
set the view for nviz other than that interactive arrow (ie command line)?
I am ultimately trying to make a nice shaded relief map, without any
perspective. I used shade.rel.sh, however obtaining nice lighting is
non-trivial with this script (things are usually too dark, regardless of sun
angle). Any ideas out there? I am using GRASS 5.0.0 on OSx 10.2.6
Thanks,
Ian
A better way to make a shaded relief map might be to use r.out.tif, which will write a tif file of your map. You might be able to adjust the tones, to lighten the shadows, by modifying the color table of the shaded relief map using r.colors.
I would be interested too in setting the view in NVIZ without using the interactive arrow, though.
Nick Cahill
On Sunday, May 18, 2003, at 05:38 AM, Ian Macmillan wrote:
Hi all, I am trying to use NVIZ and am having a hard time getting a nice bird's
eye view. The "top" button centers the image nicely, however north generally
points left diagonally (or some other random direction). Is there anyway to
set the view for nviz other than that interactive arrow (ie command line)?
I am ultimately trying to make a nice shaded relief map, without any
perspective. I used shade.rel.sh, however obtaining nice lighting is
non-trivial with this script (things are usually too dark, regardless of sun
angle). Any ideas out there? I am using GRASS 5.0.0 on OSx 10.2.6
Thanks,
Ian
Hello
For a long time also I have struggled with the limitations of accurate
positioning in NVIZ and have had much more success using the older SG3d
(which only runs on Silicon Graphics workstations at present although it
might be possible to port it to other Unix using the software at
http://www.thp.uni-duisburg.de/Ygl/ ). I am not sure but I think the
'interactive arrow' positioning may be inherent to the 'togl' Tcl/TK to
OpenGL interface that is used in NVIZ. I have found it impossible to use
for very precise positioning.
Would it be helpful to have six positioning sliders for easting, northing
and elevation (i.e. position) and yaw, pitch and roll Euler angles (i.e.
attitude / viewing direction) of the camera / observer? I think this would
be a good idea and may be able to be added to NVIZ---it would be good if
there was some sort of wishlist consensus about this.
You may be able to obtain the same effect by manually editing a 3dview file
in the GRASS database and loading it from the option on the file menu in NVIZ.
This sort of works in the CVS version but I'm not sure if it's there in
5.0.2. There is no command-line option to load a 3dview file at present
like there is in SG3d but I'm fairly sure it would be trivial to add it.
Paul Kelly
On Sun, 18 May 2003, Nick Cahill wrote:
A better way to make a shaded relief map might be to use r.out.tif,
which will write a tif file of your map. You might be able to adjust
the tones, to lighten the shadows, by modifying the color table of the
shaded relief map using r.colors.
I would be interested too in setting the view in NVIZ without using the
interactive arrow, though.
Nick Cahill
On Sunday, May 18, 2003, at 05:38 AM, Ian Macmillan wrote:
> Hi all, I am trying to use NVIZ and am having a hard time getting a
> nice bird's
> eye view. The "top" button centers the image nicely, however north
> generally
> points left diagonally (or some other random direction). Is there
> anyway to
> set the view for nviz other than that interactive arrow (ie command
> line)?
>
> I am ultimately trying to make a nice shaded relief map, without any
> perspective. I used shade.rel.sh, however obtaining nice lighting is
> non-trivial with this script (things are usually too dark, regardless
> of sun
> angle). Any ideas out there? I am using GRASS 5.0.0 on OSx 10.2.6
>
> Thanks,
> Ian
>
On Sun, 18 May 2003 20:38, Ian Macmillan wrote:
I used shade.rel.sh, however obtaining nice lighting is
non-trivial with this script (things are usually too dark, regardless
of sun angle). Any ideas out there?
Just a quick check, are you using shade.rel.sh on a lat/lon projection?
If so the script produces terrible results because it assumes x, y and z
are in the same scale. I have modified the script to scale
appropriately when a scale command line option is given, I can send you
a copy, if this is your problem.
Regards
Gordon
--
Gordon Keith
Programmer/Data Analyst
Marine Acoustics
CSIRO Marine Research
http://www.marine.csiro.au
Religion and natural science are fighting a joint battle
in an incessant, never relaxing crusade against
scepticism, against dogmatism, against disbelief and
against supersitition. The rallying cry in this crusade
has always been, and will always be "On to God!"
- Max Planck - quantum physicist