[GRASS5] [bug #979] (grass) NVIZ Load / Save 3-D Settings doesn't work

[Helena Mitasova]

Request Tracker wrote:

> this bug's URL: http://intevation.de/rt/webrt?serial_num=979
> -------------------------------------------------------------------------
>
> Subject: NVIZ Load / Save 3-D Settings doesn't work
>
> Platform: SGI/Irix
> grass downloaded at: CVS Server, Germany
> grass binary for platform: I compiled the sources myself
> grass sources source: GRASS 5.0.0pre3
>
> Load / Save 3-D Settings option in File menu in NVIZ is disabled (and doesn't work).

It works here on LINUX. We use it all the time. Are you sure that you are using GRASS 5.0.0pre3?

> It is mentioned in the tcl/tk source file that these options are disabled because they are buggy; I tried enabling them just to try but loading a 3d view has no effect on the position settings in NVIZ.

It saves not only the position settings but also the size of widnows and lot of other things so you can start exactly
where you left it. It sounds like you are using some old version of NVIZ. Note that the NVIZ state file is NOT the 3dview file.

>
> NVIZ is of no use for my work without accurate observer position settings (easting, northing, elevation, field of view etc.) and I am currently using SG3d and GRASS 4.3 with reasonably successful results (SG3d can read the 3dview files created either manually or with d.3d, which enable a lot of control over the exact observer position).
> However I would very much like to make use of the 3-D vectors in GRASS 5.1; for this I need NVIZ and also the missing advanced positioning functionality.

saving state in NVIZ is much better now that it was for SG3d (it saves also the vectors and sites and lot of other settings
that SG3d did not save). As I said, this it is not saved in 3dview file but in a separate file - I usually store it in a directory along with
the images - so it is not stored in GRASS database as 3dview was. Just save one file with your favourite settings and
then you can modify it manually

> Perhaps in a year or so's time I may be in a position to fix the problem myself, but at the minute I would be out of my depth: beyond the tcl/tk functions, there are several layers of nested function calls back through the gsurf library to the low-level G_get_3dview and G_save_3dview that SG3d and d.3d use.

This is one thing that bothers me about the NVIZ design. One reason for re-designing SG3d to NVIZ by developing gsurf library
was to make the development of enhancements, customization and development of various interfaces easier.
However, it seems the the result is just the opposite. While adding such features as a wide range of possibilities to display sites,
displaying scale and legends or adding volumes to SG3d was possible and was done relatively quickly, it seems to be
extremely complex if not next to impossible in the current structure of NVIZ code.

> I am quite surprised that such an obvious piece of functionality is still missing, but perhaps exact positioning is not important for geographical applications? (I am approaching this from an engineering background). I hope anyway that submitting this to the bugtracker will bring it more to the forefront of attention of the relevant person.

exact positioning and saving the state is absolutely crucial for GIS applications and it is functional, so please first check
the version of NVIZ that you are using and then if it is up to date and still does not work it may be an SGI specific issue
(we can check with Bill Brown whether he has it working as I am not using SGI any more). Or you are trying to load 3dview
fiel instead of nviz state file.

>
>
> Paul Kelly
>
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