Class KFbxAnimEvaluator is the class to use when you need to evaluate the animation in a scene:
// Let’s assume that myScene has been created already
KFbxAnimEvaluator* mySceneEvaluator = MyScene->GetEvaluator();
But KFbxAnimEvaluator is actually an abstract class. When you call KFbxScene::GetEvaluator in the above code snippet, the function actually creates a KFbxAnimEvalClassic object. KFbxAnimEvalClassic is the only implementation of KFbxAnimEvaluator in this release of FBX SDK.
You can, however, implement your own evaluator class derived from KFbxAnimEvaluator. To use your evaluator class, call KFbxScene::SetEvaluator, setting the evaluator to your own evaluator object. Then, make this call, which is exactly the same call that you see in the above code snippet:
KFbxAnimEvaluator* mySceneEvaluator = MyScene->GetEvaluator();
This time, mySceneEvaluator will point to an object of your own evaluator class.