It is possible to set the value of a parameter through either:
savePMs)When a project has parameters, the RGG toolbar get a new button which select the parameter manager in the attribute editor (see red circle in the image).
Then, the list of parameters appear sorted by file and by parameter manager.
It is possible to set the value of a parameter for all project from a name by using the command line argument -P.
-PModel.t=5
-PModel.aze=test
-P/home/gaetan/eclipse-workspace/test.parameters
The parameter manager responsible for the parameter can store the current value of the monitored field into the parameter with specific methdos.