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Attaching Binary User Data to Objects

Raw binary user data on objects is available to plug-in developers through the object model as the UserDataBlob object. You can attach a user data blob to any object that supports the SceneItem.AddProperty method.

The UserDataBlob is similar to the UserDataMap, but supports storing object level binary data rather than per-component binary data. For example, if some user data is meant to apply to every point in a vertex cluster then it should be stored in a UserDataBlob, whereas, if the user data is meant to apply only to a single vertex, it should be stored at the correct index in a UserDataMap.

C++ Example: Applying a UserDataBlob to the scene root

// C++ example (using the C++ API) giving an overview of applying user data 
// to a scene object (the scene root)

   using namespace XSI;

   Application app ;
   Model root = app.GetActiveSceneRoot();

   UserDataBlob myBlob ;
   root.AddProperty( L"UserDataBlob", false, L"udb", myBlob ) ;

   // This is the structure that we would like to save inside Softimage
   struct ExampleData
   {
       double x ;
       int    y ;
       int    z ;
   } ;

   // Save the structure
   ExampleData data ;
   data.x = 90.1 ;
   data.y = 12 ;
   data.z = 14 ;

   myBlob.PutValue( (unsigned char*)&data, sizeof( ExampleData ) ) ;

   // Retrieve the structure again
   unsigned char * pBuffer = NULL ;
   unsigned int cntBuffer = 0 ;

   myBlob.GetValue( pBuffer, cntBuffer ) ;

   // We can conveniently read the contents of the user data
   // by casting back to the structure
   ExampleData * pData = (ExampleData*)pBuffer ;

   // Update our structure based on what is already on the userdatablob
   data.x = 3.15 + pData->x ;
   data.y = 12 + pData->y ;
   data.z = 0 ;

   // Save our updated values
   myBlob.PutValue( (unsigned char*)&data, sizeof( ExampleData ) ) ;

Autodesk Softimage v7.5     <     >