If the parameter block descriptor flag P_AUTO_UI is assigned it indicates that the parameter block supports automatic UI rollout management. This means that an additional set of arguments called the parameter block UI specification arguments must be provided.

Automatic rollout management is handled by 3ds Max in the methods ClassDesc2::BeginEditParams(), ClassDesc2::EndEditParams(), ClassDesc2::CreateParamDlg(), ClassDesc2::CreateParamDialog(), and so forth.

The following arguments in the ParamBlockDesc2 constructor make up the parameter map specification:

• int - The ID of the dialog template (e.g. IDD_something).
• int - The string table resource ID for the title of the dialog.
• int - A flag mask used by ClassDesc2::BeginEditParams() and ClassDesc2::EndEditParams() to determine whether the IParamMap2 should be created/deleted on this call. All the bits in the supplied mask must be set in flag argument passed to the BeginEditParams() / EndEditParams() methods for the appropriate action to take place.
• int - A flag used to control rollup creation. You may pass APPENDROLL_CLOSED to have the rollup added in the closed (rolled up) state, otherwise pass 0.
• ParamMap2UserDlgProc* - If there are controls in the dialog that require special processing a user dialog procedure can be implemented that inherits from ParamMap2UserDlgProc to process them. If not used then NULL should be passed.