[GRASS5] Strange NVIZ behavior by displaying 3D-Polygons (GRASS 5.7)

[lesejk at tiscali.cz]

Hallo,
I'm using GRASS 5.7, snapshot from 2004_03_27, own compilation on
Slackware.

When I run NVIZ with some 3D polygons (NOT lines), by changing the point
of view, the color of the raster surface becomes black.

You can't do anything with it, only to restart NVIZ. 
The underside  of the raster has the "normal" color palette. 

When you are running NVIZ with vector lines or without any vector data,
everything works fine.

Radim's sample dataset does it too (with house_roof,house_wall), 
so I suppose, there is no bug in my data. 

The snapshot from 2003_10_04 (with some older NVIZ version) does not
have these problem. So I suppose, there is some little bug in the new
version of NVIZ.

Thank you

Jáchym
-- 
Jachym Cepicky
e-mail: jachym.cepicky at centrum.cz
URL: http://les-ejk.cz