[GRASS5] NVIZ - strange phenomena

GRASS GIS GRASS GIS developer
1

Hi,

trying to grow forests on elevation models by Jachyms fine script
http://www.fle.czu.cz/~jachym/programs/trees-0.5.pl I came across several
strange effects in the current version of NVIZ (built from source on
Debian).
When 3d-vectors (jachym-trees) are included, the lighting/coloring of the
raster-surfaces turns pitch-black after changes of the point of view.

However, cranking up all lighting parameters to max and raising the
light-source to 1000 helps get a greyish impression of the surface.

That's where the magic begins: A change of the trees color (say, from green
to RED (on the greyish surface)) is displayed as expected (red tree on grey
ground). HOWEVER, the next change of color (say, RED to BLUE) results in a
blue tree standing on a RED surface.

Puzzled,
Peter

--
Dr. Peter Löwe

Diplom-Geograph

<loewe@geomancers.net>
<peter.loewe@gmx.de>

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2

Jachym,

After having learned about your trees-0.5.pl I grabbed it too, and, wow, it is wow!!! But - I'm having the same problem Peter Löwe reported.

The commands I used:

trees-0.5.pl in=drzewa out=drzewa_3d elevation=dem vvar=1.0 crown=1.0 pvar=1.0

nviz elevation=dem vector=drzewa_3d_trunks,drzewa_3d

After the second press of DRAW button in NVIZ my DEM becomes almost completely black and the raster overlay is not visible. However - when layer "drzewa_3d_trunks" is displayed ALONE all is fine. The problem occures only when displaying the crowns too - "drzewa_3d" in my case.

Do you guess what could be the reason? Should I provide more information? Is anybody having the same problem?

My system:
grass-6.0.cvs_src_snapshot_2005_01_22
built from source on Mandrake 10.1 with tcltk 8.4

Maciek

----- Original Message ----- From: ""Peter Löwe"" <peter.loewe@gmx.de>
To: <grass5@grass.itc.it>
Sent: Tuesday, February 08, 2005 10:23 AM
Subject: [GRASS5] NVIZ - strange phenomena

Hi,

trying to grow forests on elevation models by Jachyms fine script
http://www.fle.czu.cz/~jachym/programs/trees-0.5.pl I came across several
strange effects in the current version of NVIZ (built from source on
Debian).
When 3d-vectors (jachym-trees) are included, the lighting/coloring of the
raster-surfaces turns pitch-black after changes of the point of view.

However, cranking up all lighting parameters to max and raising the
light-source to 1000 helps get a greyish impression of the surface.

That's where the magic begins: A change of the trees color (say, from green
to RED (on the greyish surface)) is displayed as expected (red tree on grey
ground). HOWEVER, the next change of color (say, RED to BLUE) results in a
blue tree standing on a RED surface.

Puzzled,
Peter

--
Dr. Peter Löwe

Diplom-Geograph

<loewe@geomancers.net>
<peter.loewe@gmx.de>