VTK系列——拾取点/显示当前点选点并删除上次的点选点

1 前言：vtkpick系列在《VTK图形图像开发进阶》一书中讲得非常详细；这里不再赘述，在实际项目中会遇到需要点选一个点标记出来，在下次选择另一个点的时候继续标记同时删除上一次的标记点。

2 代码：

class PointPickerInteractorStyle : public vtkInteractorStyleTrackballCamera
{
public:
    static PointPickerInteractorStyle* New();
    vtkTypeMacro(PointPickerInteractorStyle, vtkInteractorStyleTrackballCamera)
    PointPickerInteractorStyle()
    {
        last_picked_actor=NULL;
       
    }
    virtual ~PointPickerInteractorStyle()
    {
       
    }
    virtual void OnRightButtonDown()
    {
        //打印鼠标左键像素位置
        if(this->Interactor->GetControlKey())
        {
            std::cout << "Picking pixel: " << this->Interactor->GetEventPosition()[0]
                      << " " << this->Interactor->GetEventPosition()[1] << std::endl;
            //注册拾取点函数
            this->Interactor->GetPicker()->Pick(
                        this->Interactor->GetEventPosition()[0],
                    this->Interactor->GetEventPosition()[1], 0,  // always zero.
                    this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()
                    );
            //打印拾取点空间位置
            this->Interactor->GetPicker()->GetPickPosition(picked);
            std::cout << "Picked value: " << picked[0] << " " << picked[1] << " " << picked[2] << std::endl;
            //如果之前选择了其他点，删除上一次的标记点
            if(this->last_picked_actor)
            {
                this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()->RemoveActor(last_picked_actor);
//                last_picked_actor->Delete();
//                last_picked_actor=vtkActor::New();
            }

	    //获取此次的标记点。
            this->last_picked_actor=GetActor();
            if(this->last_picked_actor)
            {
                //标记出来，
                this->last_picked_actor->SetScale(0.02);
                this->last_picked_actor->GetProperty()->SetColor(1.0, 0.0, 0.0);
                this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer()->AddActor(this->last_picked_actor);
            }
            vtkInteractorStyleTrackballCamera::OnRightButtonDown();

        }


    }
    int flag;
    double picked[3];//选取的点坐标
private:
    vtkActor* last_picked_actor;
    inline vtkActor* GetActor()
    {

        vtkSmartPointer<vtkSphereSource> sphereSource =
                vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->Update();

        vtkSmartPointer<vtkPolyDataMapper> mapper =
                vtkSmartPointer<vtkPolyDataMapper>::New();
        mapper->SetInputConnection(sphereSource->GetOutputPort());
        vtkActor* actor = vtkActor::New();
        actor->SetMapper(mapper);
        actor->SetPosition(picked);
        return actor;
    }
};

3 参考文献 

《VTK图形图像开发进阶》

  http://blog.youkuaiyun.com/webzhuce/article/details/72802322