角色注册主要通过继承自类dtDAL::ActorPluginRegistry类来实现，重写其中的RegisterActorTypes()即可；在对象工厂ObjectFactory中保存了“角色类型到负责创建角色对象的全局函数”的Map；

关键函数有：

 dtCore::RefPtr<BaseActorObject> ActorPluginRegistry::CreateActor(const ActorType& type){dtCore::RefPtr<BaseActorObject> proxy = mActorFactory->CreateObject(dtCore::RefPtr<const ActorType>(&type));proxy->Init(type);proxy->InitDefaults();return proxy;}
void XXGameActorsRegistry::RegisterActorTypes()
{
XXActorType = new
dtDAL::ActorType("XX","TutorialActors",
"Simple tank that moves and acts like a basic hover craft.");
mActorFactory->RegisterType<XXActorProxy>(XXActorType.
get());
}



在动态链接库Dll中导出全局函数：

extern "C" TUTORIAL_HOVER_EXPORT dtDAL::ActorPluginRegistry*
CreatePluginRegistry()
{
return new TutorialGameActorsRegistry();
}
/
//
extern "C" TUTORIAL_HOVER_EXPORT void
DestroyPluginRegistry(dtDAL::ActorPluginRegistry *registry)
{
delete registry;
}








核心了对象工厂实现代码如下：
template<typename BaseType, typename DerivedType>BaseType *construct(){return new DerivedType();}/*** This class is a template object factory.  It allows one to* create any type of object as long as there is a common base* class.  The common base class is defined on a per-factory* basis using the templated parameter <code>BaseType</code>.* @note*   The ObjectFactory implementation only supports objects with*   a default constructor.  It will not work with objects that*   only have named constructors.*/template<typename UniqueIdTypeClass,typename BaseTypeClass,typename ltCmpClass=std::less<UniqueIdTypeClass> >class ObjectFactory : public osg::Referenced{public:typedef UniqueIdTypeClass UniqueIdType;typedef BaseTypeClass BaseType;typedef ltCmpClass ltCmp;typedef BaseType *(*createObjectFunc)(); /// Function pointer type for functions creating objects.typedef std::map<UniqueIdType,createObjectFunc,ltCmp> ObjectMap;typedef typename ObjectMap::iterator ObjTypeItor;typedef typename ObjectMap::const_iterator ObjTypeItorConst;ObjectFactory() {}  // constructorprotected:virtual ~ObjectFactory() {}public:/*** Registers a new type of object with the factory.* @return false if the type is a duplicate.*/template<typename DerivedType>bool RegisterType(UniqueIdType id){if (this->objectTypeMap.find(id) != this->objectTypeMap.end()){return false;}this->objectTypeMap[id] = &construct<BaseType,DerivedType>;return true;}/*** Removes an existing object type from the factory's known list* of object types.*/void RemoveType(UniqueIdType id) {this->objectTypeMap.erase(id);}/*** Checks to see if the factory can create objects of the given type.* @param id The type of object to check for.* @return True if the type is supported, false otherwise.*/bool IsTypeSupported(UniqueIdType id) const{ObjTypeItorConst itor(this->objectTypeMap.find(id));if (itor != this->objectTypeMap.end()){return true;}else{return false;}}/*** Gets a list of types that this factory knows how to create.*/void GetSupportedTypes(std::vector<UniqueIdType> &types) const{types.clear();for (ObjTypeItorConst itor=this->objectTypeMap.begin();itor != this->objectTypeMap.end(); ++itor){types.push_back(itor->first);}}/*** Creates a new object.* @param id - Type of object to create.* @return Returns a pointer to the newly created object or NULL if the given id has not been registered.* @throw Exception is thrown if the factory does not know how to create*  the requested type.*/BaseType* CreateObject(const UniqueIdType id) const{ObjTypeItorConst itor(this->objectTypeMap.find(id));// We cannot create a new object if we do not know what type it is// so throw an exception.if (itor == this->objectTypeMap.end()){return NULL;}return (itor->second)();}const ObjectMap& GetMap() const { return objectTypeMap; }private:///Maps a unique id to a function pointer that when called creates an///object of the appropriate type.ObjectMap objectTypeMap;};