TerraView Main Concepts

Project

Project is a  small  file (*.tview) that defines the user workspace by keeping the minimal information about the layers used. For each layer added to the project, informations such as: connection info, visual characteristics of line, point or polygons and Spatial Reference System are serialized in this file. 

Data Source

TerraView supports different data sources such as:

Layer

Layer is the representation of one dataset inside TerraView application. Each layer correspond to a vector, raster, or tabular dataset stored in one of the datasources available.

Layer Explorer

Layer explorer is a tree structure used to present the layers contained in a project. A folder layer is an element in this tree with layers inside it. A context menu is provided (righ click mouse) to quickly access relevant operation to each layer type.

Data Table

Data Table is used to present the textual data associated with each layer. Some context menus are also provided to access the relevant operations in a row, line etc.

Map Display

The Map Display is the area used to render the selected layers. It can have its own SRID (set or unset) or by default it takes the first valid SRID among the selected layers.

Style

The style defines how a layer should be rendered in the Map Display. For each type of geometric representation (line, point, polygon) a style can be set.  A style is defined by a set of rules and the rules are composed of sets of symbolizers.


Style Explorer

Style Explorer displays the style associated with a layer in a interface where it is possible to add, remove or modify the symbols that make up the style. A property browser displays all attributes of a selected symbol and it is modifiable. 

SRS / SRID

SRS stands for Spatial Reference Systems and SRID defines an unique if for a spatial reference. To correctly render a Layer  in a Map Display it is necessary to have consistent SRIDs (projections) for both the Map Display and the Layer.


Plugins

Plugins are modules of TerraView that can easily be associated with or removed from the application. An example of these plugins are the drivers that support different data sources.