如何判断一个vtkActor的类型

在VTK管线流程中，有个重要的角色就是vtkActor，本文旨在学习示例代码，学习使用方法。

#include <vtkSmartPointer.h>#include <vtkActor.h>#include <vtkActorCollection.h>#include <vtkCubeAxesActor.h>#include <vtkPolyData.h>#include <vtkPolyDataMapper.h>#include <vtkRenderWindow.h>#include <vtkRenderWindowInteractor.h>#include <vtkRenderer.h>#include <vtkSphereSource.h>int main(int, char *[]){// SpherevtkSmartPointer<vtkSphereSource> sphereSource = vtkSmartPointer<vtkSphereSource>::New();sphereSource->Update();vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();mapper->SetInputConnection(sphereSource->GetOutputPort());vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();actor->SetMapper(mapper);// Cube axesvtkSmartPointer<vtkCubeAxesActor> cubeAxesActor = vtkSmartPointer<vtkCubeAxesActor>::New();// Create a renderer and render windowvtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();cubeAxesActor->SetCamera(renderer->GetActiveCamera());renderer->AddActor(actor);renderer->AddActor(cubeAxesActor);// Determine the types of the actors - method 1{std::cout << "Method 1:" << std::endl;vtkActorCollection* actorCollection = renderer->GetActors();actorCollection->InitTraversal();for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++){vtkActor* nextActor = actorCollection->GetNextActor();std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;std::string className = nextActor->GetClassName();std::string wantedClass = "vtkCubeAxesActor";if(className == wantedClass){std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;}else{std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;}}}// Determine the types of the actors - method 2{std::cout << "Method 2:" << std::endl;vtkActorCollection* actorCollection = renderer->GetActors();actorCollection->InitTraversal();for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++){vtkActor* nextActor = actorCollection->GetNextActor();std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;if(nextActor->IsA("vtkCubeAxesActor")){std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;}else{std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;}}}// Determine the types of the actors - method 3{std::cout << "Method 3:" << std::endl;vtkActorCollection* actorCollection = renderer->GetActors();actorCollection->InitTraversal();for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++){vtkActor* nextActor = actorCollection->GetNextActor();std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;if(vtkCubeAxesActor::SafeDownCast(nextActor) != 0){std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;}else{std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;}}}// Determine the types of the actors - method 4{std::cout << "Method 4:" << std::endl;vtkActorCollection* actorCollection = renderer->GetActors();actorCollection->InitTraversal();for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++){vtkActor* nextActor = actorCollection->GetNextActor();std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;if(dynamic_cast<vtkCubeAxesActor*>(nextActor) != 0){std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;}else{std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;}}}// Render the scenevtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();renderWindow->AddRenderer(renderer);vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();renderWindowInteractor->SetRenderWindow(renderWindow);renderer->ResetCamera();renderWindow->Render();renderWindowInteractor->Initialize();renderWindowInteractor->Start();return EXIT_SUCCESS;}

获取当前vtkRenderer的所有ACTORS：

vtkActorCollection* actorCollection = renderer->GetActors();

遍历：

actorCollection->InitTraversal();for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++){vtkActor* nextActor = actorCollection->GetNextActor();···}

获取ACTOR类名

std::string className = nextActor->GetClassName();

四种不同的判断方法

/****************方法一**************************/std::string wantedClass = "vtkCubeAxesActor";if(className == wantedClass){// true}else{// false}/****************方法二**************************/if(nextActor->IsA("vtkCubeAxesActor")){// true}else{// false}/****************方法三**************************/if(vtkCubeAxesActor::SafeDownCast(nextActor) != 0){// true}else{// false}/****************方法四**************************/if(dynamic_cast<vtkCubeAxesActor*>(nextActor) != 0){// true}else{// false}