Building Softimage Plug-ins with C#

Building Softimage Plug-ins with C#

All C# plug-ins for Softimage define self-installing custom plug-in items available in the Softimage Object Model. These include commands, events, filters, menus, operators and properties. Custom Display and GraphicSequencer plug-in items are not available to C# because they are only implemented in the C++ API.

The sample code in this section is generated automatically by one of the Softimage plug-in wizards and it is highly recommended to use the wizards to set up your plug-ins. See Creating C# Plug-ins for more details.

Plug-in Registration

To get a hook into Softimage, you make sure you include the XSIOM (object model) assembly and then create a class to register the plug-in in Softimage (XSIPlugin in the example below). Each plug-in item is defined within its own class and you use the name of the plug-in item class to register the plug-in item:

using System;
using System.Reflection;
using XSIOM; // Softimage Object model assembly

public class XSIPlugin
{
   public bool Load( PluginRegistrar in_reg )
   {
       in_reg.Author = "Kilroy";
       in_reg.Name = "MyCSharpPlugin";
       in_reg.Major = 1;
       in_reg.Minor = 0;

       in_reg.RegisterCommand( "MyCSharpCmd", null );
       in_reg.RegisterMenu( siMenuAnchorPoints.siMenuMainTopLevelID, "MyCSharpMenu", false, false );
       in_reg.RegisterProperty( "MyCSharpCustomProp" );
       in_reg.RegisterEvent( "MyCSharpSelectionEvent", siEventID.siOnSelectionChange );
       in_reg.RegisterFilter( "MyCSharpTriangleFilter", siFilterType.siFilterSubComponentPolygon );
       in_reg.RegisterOperator( "SplatterCS" );
       in_reg.RegisterCommand( "DotNETHost", null );
       return true;
   }

   public bool UnLoad( PluginRegistrar in_reg )
   {
       return true;
   }
}

Note that once the Load method terminates, the class uesd to register the plug-in in Softimage (XSIPlugin in the example above) is destroyed. This is by design since the plug-in is unloaded by Softimage once the registration step is done. For more information about Softimage plug-ins in general, see Self-Installing Plug-ins.

Defining the Plug-in Items

The plug-in item class definition must implement the callbacks as public methods (rather than imported function callbacks as it is in the C++ API).

public class MyCSharpCmd
{
   public MyCSharpCmd()
   {
   }

   // Command mandatory implementation
   public bool Init( Context in_ctxt )
   {
       // ...
   }

   public bool Execute( Context in_ctxt )
   {
       // ...
   }

   // etc.
}

For those already familiar with developing plug-ins with the C++ API, this table maps the C# style to the C++ API style:

Plug-in Item to Create	Comments	C# Public Methods to Create	C++ Callback Function
Custom Commands	Implement a class (for example, MyCSharpCmd)	MyCSharpCmd.Init MyCSharpCmd.Execute	MyCSharpCmd_Init MyCSharpCmd_Execute
Custom Events	Implement a class (for example, MyCSharpSelectionEvent)	MyCSharpSelectionEvent.OnEvent	MyCSharpSelectionEvent_OnEvent
Custom Filters	Implement a class (for example, MyCSharpTriangleFilter)	MyCSharpTriangleFilter.Match MyCSharpTriangleFilter.Subset MyCSharpTriangleFilter.IsApplicable	MyCSharpTriangleFilter_Match MyCSharpTriangleFilter_Subset MyCSharpTriangleFilter_IsApplicable
Standard and Contextual Menus	Implement a class (for example, MyCSharpMenu). Add callbacks by defining methods in the menu class which contain calls to Menu.AddCallbackItem.	MyCSharpMenu.Init MyCSharpMenu.<menu-item_callback_name>	MyCSharpMenu_Init MyCSharpMenu_<menu-item_callback_name>
Custom Operators	Implement a class (for example, SplatterCS)	SplatterCS.Update SplatterCS.Init SplatterCS.Define SplatterCS.DefineLayout SplatterCS.PPGEvent	SplatterCS_Update SplatterCS_Init SplatterCS_Define SplatterCS_DefineLayout SplatterCS_PPGEvent
Custom Properties	Implement a class (for example, MyCSharpCustomProp). Handling logic for property pages in C# mirrors how the C++ API handles logic, unlike the scripting languages that use the Softimage Object Model. For more information, see the PPGEventContext documentation.	MyCSharpCustomProp.Define MyCSharpCustomProp.DefineLayout MyCSharpCustomProp.PPGEvent	MyCSharpCustomProp_Define MyCSharpCustomProp_DefineLayout MyCSharpCustomProp_PPGEvent

Since the Custom Display (View) callbacks and the GraphicSequencer callbacks are not implemented in the object model, they are not available for development with the C# language.

Autodesk Softimage v7.5