我写了一个使用vtkPoints＆gt;生成螺旋的VTK应用程序。 vtkPolyLine＆gt; vtkPolyData＆gt; vtkPolyDataMapper并显示它。如果在程序初始化时静态完成，这可以正常工作。 现在，我想动态添加新的数据点。目的是实时显示测量结果，因此将以特定间隔添加新数据。
目前，我刚刚实现了一个TimerEvent来更新vtkPoints和vtkPolyLine。但是，程序只显示在vtkRenderWindowInteractor启动之前生成的静态数据。我也尝试使用＆＃34; Modified（）＆＃34;和＆＃34;更新（）＆＃34;调用几乎所有对象，尝试删除，重新生成并向渲染器添加新actor - 但没有成功！我在下面添加了我的C ++代码......
以下邮件列表问题是关于这个问题，但给出的解决方案对我有用： http://public.kitware.com/pipermail/vtkusers/2006-November/038377.html
以下问题似乎有关，但没有有用的答案： VTK: update data points in renderWindow at every simulation timestep
我使用Visual Studio Community 2017和VTK 8.0.0，都编译为Win32目标。
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkRenderingContextOpenGL2);
VTK_MODULE_INIT(vtkRenderingVolumeOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);
VTK_MODULE_INIT(vtkRenderingFreeType);
#include <vtkSmartPointer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkConeSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkProperty.h>
#include <vtkPoints.h>
#include <vtkPolyLine.h>
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
vtkSmartPointer<vtkPolyLine> polyLine = vtkSmartPointer<vtkPolyLine>::New();
int numOfPoints = 0;
double t = 0;
void NextPoint() {
double x = t * cos(t);
double y = t * sin(t);
points->InsertNextPoint(x, y, t);
polyLine->GetPointIds()->InsertNextId(numOfPoints);
numOfPoints++;
t += 0.1;
}
vtkSmartPointer<vtkPolyData> generateEllipse() {
// Add some points so we actually see something at all...
for (int i = 0; i < 100; ++i) {
NextPoint();
}
vtkSmartPointer<vtkCellArray> cells = vtkSmartPointer<vtkCellArray>::New();
cells->InsertNextCell(polyLine);
vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
polyData->SetPoints(points);
polyData->SetLines(cells);
return polyData;
}
class vtkTimerCallback : public vtkCommand
{
public:
static vtkTimerCallback *New()
{
vtkTimerCallback *cb = new vtkTimerCallback;
cb->TimerCount = 0;
return cb;
}
virtual void Execute(vtkObject *vtkNotUsed(caller), unsigned long eventId,
void *vtkNotUsed(callData))
{
if (vtkCommand::TimerEvent == eventId)
{
NextPoint(); // Add another point to polyData
++this->TimerCount;
cout << this->TimerCount << endl;
}
}
private:
int TimerCount;
};
int main(int argc, char** argv) {
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
vtkSmartPointer<vtkRenderWindowInteractor> rwi = vtkSmartPointer<vtkRenderWindowInteractor>::New();
rwi->SetRenderWindow(renderWindow);
vtkSmartPointer<vtkPolyData> data = generateEllipse();
vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputData(data);
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetDiffuseColor(255, 255, 0);
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
renderWindow->AddRenderer(renderer);
renderer->AddActor(actor);
renderer->ResetCamera();
renderWindow->Render();
// Add Timer Event...
rwi->Initialize();
vtkSmartPointer<vtkTimerCallback> cb = vtkSmartPointer<vtkTimerCallback>::New();
rwi->AddObserver(vtkCommand::TimerEvent, cb);
int timerId = rwi->CreateRepeatingTimer(100); // every 100ms
std::cout << "timerId: " << timerId << std::endl;
// Start Displaying...
rwi->Start();
return 0;
}
答案 0 :(得分：2)
问题是单元格不是由指针存储的 - 当你调用cells->InsertNextCell(polyLine);数据被复制而不是指向时，为了在数组中创建单元格的有效存储（整个实现是实际上在vtkCellArray的标题中，你可以检查出来）。因此，当您更新polyLine时，它对polydata没有影响，因为polydata有自己的副本，您没有更新。以下代码适用于我（您必须公开polydata和cellArray）：
virtual void Execute(vtkObject *vtkNotUsed(caller), unsigned long eventId,
void *vtkNotUsed(callData))
{
if (vtkCommand::TimerEvent == eventId)
{
NextPoint(); // Add another point to polyData
cells->Initialize(); // reset the cells to remove the old spiral
cells->InsertNextCell(polyLine); // re-insert the updated spiral
cells->Modified(); // required to update
data->Modified(); // required to update
++this->TimerCount;
cout << polyLine->GetNumberOfPoints() << endl;
renderWindow->Render(); // refresh the render window after each update
}
}
答案 1 :(得分：1)
昨天我使用vtkProgrammableDataObjectSource作为DataSource制定了另一种解决方案。 Tomj的解决方案是更直接和简单的解决方案......但是，vtk.org上没有C ++示例代码，它解释了如何使用vtkProgrammableDataObjectSource，我必须通过反复试验来解决它。所以我会在这里发布，因为它可能对其他人有所帮助：
#include <vtkAutoInit.h>
VTK_MODULE_INIT(vtkRenderingOpenGL2);
VTK_MODULE_INIT(vtkRenderingContextOpenGL2);
VTK_MODULE_INIT(vtkRenderingVolumeOpenGL2);
VTK_MODULE_INIT(vtkInteractionStyle);
VTK_MODULE_INIT(vtkRenderingFreeType);
#include <vtkSmartPointer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkConeSource.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkProperty.h>
#include <vtkPoints.h>
#include <vtkPolyLine.h>
#include <vtkProgrammableFilter.h>
#include <vtkCallbackCommand.h>
#include <vtkPolyDataStreamer.h>
#include <vtkProgrammableDataObjectSource.h>
vtkSmartPointer<vtkProgrammableDataObjectSource> pDOS = vtkSmartPointer<vtkProgrammableDataObjectSource>::New();
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
vtkSmartPointer<vtkPoints> points = vtkSmartPointer<vtkPoints>::New();
vtkSmartPointer<vtkPolyLine> polyLine = vtkSmartPointer<vtkPolyLine>::New();
int numOfPoints = 0;
double t = 0;
void NextPoint() {
double x = t * cos(t);
double y = t * sin(t);
points->InsertNextPoint(x, y, t);
polyLine->GetPointIds()->InsertNextId(numOfPoints);
numOfPoints++;
t += 0.1;
}
void generateEllipse(void *caller) {
vtkProgrammableDataObjectSource *pDOS = vtkProgrammableDataObjectSource::SafeDownCast((vtkObjectBase*)caller);
vtkSmartPointer<vtkCellArray> cells = vtkSmartPointer<vtkCellArray>::New();
cells->InsertNextCell(polyLine);
vtkSmartPointer<vtkPolyData> polyData = vtkSmartPointer<vtkPolyData>::New();
polyData->SetPoints(points);
polyData->SetLines(cells);
pDOS->SetOutput(polyData);
}
int counter2 = 0;
void TimerCallbackFunction(vtkObject* caller, long unsigned int vtkNotUsed(eventId), void* clientData, void* vtkNotUsed(callData)) {
cout << "timer callback: " << counter2 << endl;
// To avoid globals we can implement this later...
// vtkSmartPointer<vtkProgrammableDataObjectSource> pDOS =
// static_cast<vtkProgrammableDataObjectSource*>(clientData);
vtkRenderWindowInteractor *rwi =
static_cast<vtkRenderWindowInteractor*>(caller);
NextPoint();
pDOS->Modified();
rwi->Render();
renderer->ResetCamera(); // Optional: Reposition Camera, so it displays the whole object
counter2++;
}
int main(int argc, char** argv) {
vtkSmartPointer<vtkRenderWindow> renderWindow =
vtkSmartPointer<vtkRenderWindow>::New();
vtkSmartPointer<vtkRenderWindowInteractor> rwi = vtkSmartPointer<vtkRenderWindowInteractor>::New();
rwi->SetRenderWindow(renderWindow);
pDOS->SetExecuteMethod(&generateEllipse, pDOS);
vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
mapper->SetInputConnection(pDOS->GetOutputPort());
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetDiffuseColor(255, 255, 0);
renderWindow->AddRenderer(renderer);
renderer->AddActor(actor);
renderer->ResetCamera();
renderWindow->Render();
// Add Timer Event...
vtkSmartPointer<vtkCallbackCommand> timerCallback = vtkSmartPointer<vtkCallbackCommand>::New();
timerCallback->SetCallback(TimerCallbackFunction);
rwi->Initialize();
rwi->CreateRepeatingTimer(100);
rwi->AddObserver(vtkCommand::TimerEvent, timerCallback);
// Start Displaying...
rwi->Start();
return 0;
}