Sunday, 9 December 2012

Virtual Terrain Project

VTerrain.org is an open source project, that has the goal to "foster the creation of tools for easily constructing any part of the real world in interactive, 3d digital form", as declaims its own web site.   Born from an idea of Ben Discoe, an experienced 3D programmer, the Virtual Terrain Project dates back from 1997, and is still one of the most important sites and updated documentation for territorial display in real time.



The numerous pages of VTerrain.org constitute a sort of wikipedia, where you can find and compare the various techniques discussed related to 3D programming.



But VTerrain is not just theory.  In fact, VTP is primarily a software that consists of two programs, VTBuilder and Enviro;  the first is a "tool for viewing and processing many kinds of geospatial data".
As Ben tells, "Enviro is the VTP runtime environment.  It provides an interactive, realtime 3D navigation of your virtual terrain".

Basically, what you can do with VTerrain programs ?

VTBuilder is a 2d viewer and a processing program of geospatial data; it allows complex operations such as merges and resamples of elevation data, coordinate transformations including the possibility of adding the values ​​of regional shift.

VTBuilder allows you to cut and join the grids of elevation from open sources, as OpenDEM, SRTM or LiDAR surveys.





The "resampling" of VTBuilder allows you to save Data Terrain Model grids into the BT format, viewable, through the GDAL library, into QuantumGIS OpenEnv, TatuckGis, gvSIG, and many other GIS software.


Enviro is instead a 3D visualization tool allows you to view the ground with a colorful theming based on height and superimposition of vector and raster layers adapted to difficult terrain. Enviro has proved a particularly powerful and flexible at the same time, this leads us to achieve an integration with QuantumGIS.

VTerrain plugin for QGis is a python module, that you can load into QGis through the "Fetch Python Plugins" panel, and allows you to view in 3D, with Enviro, loaded images between levels of QGis, provided they have an associated elevation grid or a TIN (Triangulated Irregular Network).


Now released version 1.21 of Virtual Terrain Project!  

You can find the installer for Windows (XP and 7) and detailed instructions at the following link:



A version of VTP integrated in Linux you can find ArcheOS integrated into the live iso that you can find at this link:



The following describes the operations to be performed on Linux ArcheOS to configure VTP to work on projects of users HOME.

Open the terminal and copy in your home directory contents
/usr/share/archeos/vtp-svn111229/TerrainApps/Data

Create, always under your home, a directory   vtp/Data   and copy your directories the same directory (in fact it would only a few, but we do so to make things easier).


After, execute VTBuilder, found under the menu "Applications> 3D" Linux ArcheOS.
The terminal window will appear with some messages and then VTBuilder.


At first launch, if they are not visible elements in the 2D window, enable the "View" menu the "World Map" and "Show UTM Boundaries".

To view an area of ​​the test, drag the file in VTBuilder "crater_0513.bt" that we will find in the directory  /home/utente/vtp/Data/Elevation/



If the territory is not shown, but instead will show a rectangle with diagonals, as in the image below, it is clearly the option "Show outline only" in the panel "View> Options". In this case, select the other hand, "Artificial color by elevation value."





Let us now Enviro. We run it through the menu "Applications> 3D" of Linux ArcheOS.





At first launch, the list of projects Enviro is empty. To enter the first project, you must select the button "Terrain Manager" panel and press "Add Path".
Add the directory vtp/Data that we have copied in our home, and press OK. Now we will find (or should) "Simple Terrain" between the land selected (if not, go back panel "Terrain Manager", and delete the first path ".. /Data", superfluous).

Selecting the "Simple Terrain" and pressing OK will open the panel "VTP Enviro OSG" and display the 3D terrain, with which we can interact.

Well, VTP is now running on your machine.



BobMaX

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