I was stuck trying to figure out why my code was running 5-6 times slower between my python project and my cpp project, and it turns out that it was because I was creating my vtkPolyData with a double data array instead of a float data array. In the below minimum example using vtkCleanPolyData, I get 35 secs for double points and 7 secs for float points. Is that a reasonable difference? For context, with vtkStaticCleanPolyData the difference was 1.01 secs vs 0.90. Also, is there a way to profile this in Visual Studio? When I run the performance profiler, it goes as far a the vtkStreamingDemandDrivenPipeline, where it counts time spent doing this->UpdateData(), but it doesn’t show the profile for the vtkCleanPolyData::RequestData function itself.
#include <vtkStaticCleanPolyData.h>
#include <vtkCleanPolyData.h>
#include <vtkSphereSource.h>
#include <vtkPoints.h>
#include <chrono>
#include <iostream>
int main() {
auto c = vtkSmartPointer<vtkCleanPolyData>::New();
auto sc = vtkSmartPointer<vtkStaticCleanPolyData>::New();
auto sph = vtkSmartPointer<vtkSphereSource>::New();
sph->SetThetaResolution(2000);
sph->SetPhiResolution(2000);
sph->Update();
auto const sphere = sph->GetOutput();
// Create a new vtkPoints with desired precision (float in this case)
vtkSmartPointer<vtkPoints> newPoints = vtkSmartPointer<vtkPoints>::New();
newPoints->SetDataTypeToFloat(); // SetDataTypeToDouble()
// Copy the old points to the new points
for (vtkIdType i = 0; i < sphere->GetPoints()->GetNumberOfPoints(); ++i) {
double p[3];
sphere->GetPoints()->GetPoint(i, p);
newPoints->InsertNextPoint(p);
}
// Set the new points to the vtkPolyData
sphere->SetPoints(newPoints);
c->SetInputData(sphere);
sc->SetInputData(sphere);
auto t0 = std::chrono::high_resolution_clock::now();
c->Update();
auto t1 = std::chrono::high_resolution_clock::now();
sc->Update();
auto t2 = std::chrono::high_resolution_clock::now();
std::cout << "vtkCleanPolyData secs = " << std::chrono::duration<double>(t1 - t0).count()
<< std::endl;
std::cout << "vtkStaticCleanPolyData secs = " << std::chrono::duration<double>(t2 - t1).count()
<< std::endl;
}