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Let's assume you have your own C4D node (for example an object) which you want to translate to an Arnold node. If built-in Arnold nodes are not satisfactory then you have to implement your own Arnold node, but that's a different topic. So in this example let's translate the MyObject object to a polymesh Arnold node.

1. Create a custom translator inherited from AbstractTranslator. You have to define a type string of the translator which should be the class name. You have to implement a constructor and all abstract methods.

   Code Block
   language cpp
   #define MY_TRANSLATOR "MyTranslator" class MyTranslator : public AbstractTranslator { // constructor: pass the translator type string to the parent class MyTranslator(BaseList2D* node, RenderContext* context) : AbstractTranslator(MY_TRANSLATOR, node, context) { } // Name of the Arnold node entry we want to export to. // Arnold node is created by the framework, override CreateArnoldNode() if needed. // The Arnold node name will be the name of the C4D node by default but you can use custom name // by overriding GetAiNodeName(). virtual char* GetAiNodeEntryName() { return "polymesh"; } // Called before the export starts to allocate array type Arnold parameters for motion blur. virtual void InitSteps(int nsteps) { // we don't have such parameters in the standard node } // Translation logic. Step is the motion blur step we are exporting at. virtual void Export(int step) { // m_aiNode is our Arnold node // GetC4DNode(true) returns the C4D node we are exporting BaseObject* object = (BaseObject*)GetC4DNode(true); BaseContainer* data = object->GetDataInstance(); // export motion blur independent values in the first motion blur step if (step == 0) { Int32 myvalue = data->GetInt32(MY_PARAM); AiNodeSetBool(m_aiNode, "self_shadows", myvalue > 10); } } };

2. Register the translator. Add a function to the main module of your plugin and handle the MSG_C4DTOA_EXTENSION_START message.

   Code Block
   language cpp
   #include "c4dtoa_api.h" // Implement your function to create custom translators. AbstractTranslator* createTranslator(BaseList2D* node, RenderContext* context) { if (node->GetType() == MyObject) { // C4DtoA will take ownership of the translator instance return new MyTranslator(node, context); } return 0; } Bool PluginMessage(Int32 id, void *data) { switch (id) { case MSG_C4DTOA_MODULE_START: { const char* myModuleName = "mymodule"; // C4DtoA module manager and API version number is passed as the argument ModuleManagerData* moduleManagerData = (ModuleManagerData*)data; ModuleManager* moduleManager = moduleManagerData->moduleManager; // check compatibility if (moduleManagerData->apiVersion != C4DTOA_API_VERSION) { GePrintF("[c4dtoa] %s module is incompatible (API version is %d, current is %d)", myModuleName, moduleManagerData->apiVersion, C4DTOA_API_VERSION); return TRUE; }   // create a new module instance Module* module = new Module(myModuleName); // register your custom translator creator function module->RegisterTranslatorCreator(createTranslator); // register the module by the manager moduleManager->RegisterModule(module); break; } } return FALSE; }

That's it! Your translator will work with the normal and IPR renderer. You can find more info about IPR here.