[GRASS5] g3d notes and possible bugs

[Helena]

> 
> 3)  Importing 2d elevation data does not result in the same display as
> importing equivalent data with a 3d site approach.  I'm fairly sure the
> fault lies in s.vol.idw - (yes, I know it was recommended that we use
> s.vol.rst, but I have yet to get the 3d one to run without crashing.)

do you use the 5.0.0 version or the one in exp ? Where does it crash and
what
it says? It used to run OK although Jaro recently reported that the
version
in the 5.0.0 release gives segmentation fault if the sites
are not exactly in the format x|y|z|#n %value (for example sites
x|y|z|%value
make it crash with segmentation fault which is obviously a bug but we
did not have
time to look into it). 

thanks,

Helena
 
>  For a smooth 3d block model the idw approach is good enough for
> testing.  Both Z (elevation) and Y (northing) are reversed when
> displayed after importing.  With the storage order being the reverse of
> physical coordinates for Y and Z its not hard to accidentally reverse
> the storage in a loop.  I think AV may have done two fixes in the code
> that cancelled each other ;-)  I'll check that in more detail and report
> later.
>