EXAMPLE OF DEFINITION OF A GDML EXTENSION WITH ASSOCIATED READER AND WRITER

In this directory you can find an example showing how to extend the GDML schema and plug-in a custom reader and writer to the system for handling the extension. For more information, please, refer to the GDML Documentation.

The Geometry is a Simple Box to which it is assigned a color as visualization attribute. The entity "color" is defined as part of the "extension" tag and properly implemented in the GDML schema extension placed inside the directory SimpleExtensionSchema. The GDML file implenting the geometry with colors extension is color_extension.gdml, in which the standard "gdml" tag has been replaced by the "gdml_simple_extension" tag, with relative location for the new schema. The GDML file is automatically loaded by the program. It is also possible to use UI commands or macros as arguments to read any standard GDML file.

HOW TO BUILD THE EXAMPLE ?

You need to have built the persistency/gdml module by having set the -DGEANT4_USE_GDML=ON flag during the CMAKE configuration step, as well as the -DXERCESC_ROOT_DIR=path_to_xercesc flag pointing to the path where the XercesC XML parser package is installed in your system.
Compile and link to generate the executable (in your CMAKE build directory):
```
% make
```
Execute the application for reading and visualizing the setup:
```
% gdml_ext read_ext.mac
```
Execute the application for also writing the setup:
```
% gdml_ext [write_ext.mac]
```