Introduction to osggis tools

 

Introduction: osggis is used to build OSG Ry from GIS data sources.

Osggis can be used:

1. Connect to the element data source (such as shapefile) and read the geometric information and attribute information;

2. Assemble a custom transformation process to convert elements into OSG ry;

3. construct linear ry, such as the street and administrative boundaries;

4. Build the stretching of linear ry, such as walls and fences;

5. Construct stretching of complex structures, such as buildings (with exterior decoration and roof textures );

5. Use a 3D model to replace the points;

6. Splice elements into terrain;

7. Organize layers with large data volumes in a grid and construct parallel cells.

8. Embed Lua code to control the data compilation process (the compilation here generally refers to the process from feature => OSG );

9. Build a mask node that can be used with osgsim: overlaynode;

10. Pre-compile or compile data in real time;

11. query the attribute of the element during running;

 

Osggis cannot be used:

1. Build terrain skin (refer to how to prepare data source)

Basic workflow:

In GIS terminology, feature is a basic data unit with vector geometric features and attributes. Osggis converts the feature in GIS into a scenario map in OSG. osggis uses an assembly line to complete the conversion process. Feature enters the wiring switch from the assembly line entry. The osggis engine transmits the feature to discrete processing units in sequence, and finally outputs the OSG scenario diagram. in osggis terminology, this process is called compilation.

Specifically, the compilation process involves:

1. Read the feature from the data source;

2. filter the feature to obtain the data you are interested in;

3. Each feature is sequentially sent to each discrete processing unit;

4. Process and combine the ry to obtain the drawable object;

5. Process and combine the drawable object to obtain the OSG node;

6. Combine the OSG nodes into an OSG scenario and return them to the user;

The above process is a basic process. In fact, the selection and configuration of processing units (filters) control how a feature is converted into an OSG ry. osggis provides several processing units. in fact, writing a processing unit by yourself is also very simple.

 

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