[GRASS-user] NViz - problem in the visualization of 3D objects

GRASS GRASS user
1

Since this is a vector, it may be related to an issue that I was reminded of last night.

If you display the wake streets vector map on top of elevation (nc_spm_08 demo data) in NVIZ, some of the streets display blue regardless of how you set the vector color. That is, some vector parts have a color display by “default” in spite of vector color settings that affect the rest of the vector object.

Michael

C. Michael Barton
Director, Center for Social Dynamics & Complexity
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
Tempe, AZ 85287-2402
USA

voice: 480-965-6262 (SHESC), 480-727-9746 (CSDC)
fax: 480-965-7671(SHESC), 480-727-0709 (CSDC)
www: http://csdc.asu.edu, http://shesc.asu.edu
http://www.public.asu.edu/~cmbarton

On Feb 14, 2013, at 11:55 AM, <grass-user-request@lists.osgeo.org>
wrote:

From: Anna Kratochvílová <kratochanna@gmail.com>

Subject: Re: [GRASS-user] NViz - problem in the visualization of 3D objects

Date: February 14, 2013 11:15:28 AM MST

To: Carla Rebelo <crrebelo@gmail.com>

Cc: <grass-user@lists.osgeo.org>, GRASS-dev <grass-dev@lists.osgeo.org>

On Thu, Feb 14, 2013 at 6:30 PM, Carla Rebelo <crrebelo@gmail.com> wrote:

Hi,

I have footprint buildings and the height value (type double
precision) of each footprint.

v.info -t map=buildings@
nodes=250
points=0
lines=0
boundaries=243
centroids=88
areas=89
islands=8
faces=0
kernels=0
primitives=331
map3d=1

After the v.extrude step "v.extrude --overwrite --verbose
input=buldings@ output=buildings3D hcolumn=Height type=area

v.info -t map=buildings3D@
nodes=646
points=0
lines=0
boundaries=0
centroids=0
areas=0
islands=0
faces=743
kernels=88
primitives=831
map3d=1

When I visualized the file 3D from NViz, I have seen some of the
buildings with a black filling (it’s black inside or the top of
building is black) …

Is it a problem of rendering? Or a problem with the topology?

Some of the buildings look ok? I’ve just tried a small example and it
works for me .

There could be a problem with the normal vectors of the faces.
Unfortunately I don’t know much about the topology of kernels.

Regards,
Anna