Resource files are used to define the settings of dialogs and parameter descriptions. Resource files are:
Every Cinema 4D installation contains the resource files of Cinema 4D's modules and core in the "resource/modules" folder. These resource files can be used as a reference.
Resources must be loaded before they can be used. They are typically loaded on start-up with the given GeResource instance.
GeDialog resource files define the layout and properties of dialog gadgets. The layout of a dialog is defined by implementing GeDialog::CreateLayout(). Within this function one can use GeDialog::LoadDialogResource() to load a resource file with the given ID (see GeDialog Manual).
For detailed information see Dialog Layout and Dialog Resource
Description resources define the parameters of NodeData based plugins that are displayed in the Attribute Manager. The name of the resource files associated with a given plugin is defined with the "Register" function that is used to register the plugin itself. See Registration.
NodeData based plugins typically must have dummy resource files, even if the parameter description is created dynamically. The description can be defined dynamically by implementing NodeData::GetDDescription() (see NodeData::GetDDescription() Manual). Within that function one can load a registered description using Description::LoadDescription().
The loaded *.res files are parsed and the descriptions are stored using description parameters (see Description Settings Manual). A parameter description is interpreted and displayed by the DescriptionCustomGui GUI element.
For detailed information see Description Resource.