VTP Enviro Documentation

Enviro is the VTP runtime environment program.  It provides an interactive, realtime 3D navigation of your virtual terrain.  There are two primary view modes: Earth and Terrain.  At startup, you chose which view you want to start with, and you can switch at any time.

Earth View

At startup, select "Earth View" and press OK.  You are now viewing the planet from space.

How to Navigate:

• To spin the viewpoint around the earth, hold down the middle mouse button.
• To zoom in and out, use the shift key and the middle mouse button to drag up and down.

Each known terrain area will be shown as a small red rectangle on the earth.  To switch to a terrain, just click within its rectangle with the left mouse button.

Commands:

• Earth - Show Time of Day
  • shows the earth illuminated by sunlight based on real, current time according to your computer's clock
• Earth - Add Point Data
  • allows you to display a set of point data (from a Shapefile) on the Earth as small yellow points.
  • Try the file Enviro/Data/PointData/vtp-users.shp to see the locations of the first 160 VTP recipients.

Terrain View

At startup, to launch with Terrain:

• Use "Select" to choose from the known terrain.
• Use "Edit Properties" to adjust the properties of the currently chosen terrain (see Terrain Creation Parameters below)

Press "OK".  The terrain will now load, which may take up to a minute.  Messages in the status bar will inform you of the loading progress.

How to Navigate:

• Here's a handy guide for using the mouse to navigate in Terrain View.

Terrain Creation Parameters

Here are some good default values for the parameters dialog, to try first to get Enviro working.

After your installation of Enviro passes this initial test, run the program again - try turning on roads, trees, roads, etc., by editing the terrain properties.

Making Your Own Terrain

• Put your data in the following directories:

  Data	Location
  elevation data (BT files)	Enviro/Data/Elevation
  geospecific images (BMP files)	Enviro/Data/GeoSpecific
  road data (RMF files)	Enviro/Data/RoadData
  building data (BCF files)	Enviro/Data/BuildingData

• Don't forget that in order to use the continuous LOD rendering, elevation files must be square-power-of-2-plus-1 in size.  For example:

  513 x 513

  1025 x 1025

  2049 x 2049

  4097 x 4097

• In the Startup Dialog, use the "Generic Terrain" setting, press "Edit Properties", and select your data in the Parameters dialog

Using Your Own Textures:

• First, learn how large a texture your computer can display.  From the Enviro Start dialog, press "OpenGL Info..." and look at the number for "Maximum Texture Dimension"
• If your terrain texture map is not larger than the maximum texture, you can use the "Single texture" option, otherwise you will need to use "4x4 Tiled texture".
• Give your texture a filename ending in it's size, e.g. "newyork_1024.bmp"
• Put your texture in in the directory Enviro/Data/GeoSpecific
• For a Single texture:
  • Your texture size must be a square power of 2, up to the limit of your computer (e.g. 512, 1024)
• For a 4x4 Tiles texture:
  • You provide a single large square image file, and Enviro will break it up for you, at runtime, into a set of 16 tiles (4x4)
  • The size of each tile must be a power of 2, up to the limit of your computer (e.g. 512, 1024)
  • Due to pixel overlap to avoid texture seams, the dimensions may seem somewhat unusual - e.g. 2045 for a 4x4 at 512, 4093 for a 4x4 at 1024
  • The filename is made up of two parts: the prefix (e.g. "hawaii_") and the image size (e.g. "4093"). The dialog lets you specify the prefix, and it computes and appends the image size, based on the tile size you specify
  • So, when you're preparing your image files, simply name them ending in a number that is their size in pixels (e.g. "hawaii_4093.bmp")

Data in a Different Location

• If you want to put your Enviro Data directory in another location, edit your Enviro.ini file and change the first line to contain the path to the data.  The path can be relative or absolute, and should leave on a trailing slash.  For example, the default path is:
      DataPath Data/
  You could change it to paths like this:
      DataPath ../../Data/
    DataPath C:\MyData\
    DataPath /home/me/mydata/

Notes for Developers

• If you want to fully customize the terrain, such as adding your own objects and behaviors to the scene, or to add a number of different terrain, it will require re-compiling Enviro
  • in Enviro.cpp, add a line to the function DeclareAllTerrain() for each terrain you want, then rebuild.

We apologize that the Enviro documentation is still very small.
However, you may find most features to be self-explanatory.  Please check the FAQ then email any questions you may have.