OBBTreeTimingDemo
VTKExamples/Cxx/DataStructures/OBBTreeTimingDemo
Code¶
OBBTreeTimingDemo.cxx
#include <vtkVersion.h> #include <vtkSmartPointer.h> #include <vtkBox.h> #include <vtkAxis.h> #include <vtkTimerLog.h> #include <vtkMath.h> #include <vtkXMLPolyDataReader.h> #include <vtkPoints.h> #include <vtkPolyData.h> #include <vtkIdList.h> #include <vtkOBBTree.h> #include <vtkRenderer.h> #include <vtkRenderWindowInteractor.h> #include <vtkRenderWindow.h> #include <vtkSmartPointer.h> #include <vtkChartXY.h> #include <vtkPlot.h> #include <vtkTable.h> #include <vtkFloatArray.h> #include <vtkContextView.h> #include <vtkContextScene.h> #include <vtkSphereSource.h> #include <vector> #include <time.h> static void RandomPointInBounds(vtkPolyData* polydata, double p[3]); static void RandomDirection(double v[3]); static void RandomLineThroughVolume(vtkPolyData* polydata, double p1[3], double p2[3]); double TimeOBBTree(vtkPolyData* polydata, int maxPoints, int numberOfTrials); int main(int, char *[]) { vtkSmartPointer<vtkSphereSource> reader = vtkSmartPointer<vtkSphereSource>::New(); reader->SetThetaResolution(30); reader->SetPhiResolution(30); reader->Update(); std::cout << "Timing OBBTree..." << std::endl; std::vector<std::pair<int, double> > results; int numberOfTrials = 100; for(int i = 1; i < 20; i++) { double t = TimeOBBTree(reader->GetOutput(), i, numberOfTrials); std::pair<int, double> result(i,t); results.push_back(result); } // Create a table with some points in it vtkSmartPointer<vtkTable> table = vtkSmartPointer<vtkTable>::New(); vtkSmartPointer<vtkFloatArray> maxPointsPerRegion = vtkSmartPointer<vtkFloatArray>::New(); maxPointsPerRegion->SetName("MaxPointsPerRegion"); table->AddColumn(maxPointsPerRegion); vtkSmartPointer<vtkFloatArray> runtime = vtkSmartPointer<vtkFloatArray>::New(); runtime->SetName("Run time"); table->AddColumn(runtime); // Fill in the table with some example values size_t numPoints = results.size(); table->SetNumberOfRows(numPoints); for(size_t i = 0; i < numPoints; ++i) { table->SetValue(i, 0, results[i].first); table->SetValue(i, 1, results[i].second); std::cout << "Put " << results[i].first << " " << results[i].second << " in the table." << std::endl; } // Set up the view vtkSmartPointer<vtkContextView> view = vtkSmartPointer<vtkContextView>::New(); view->GetRenderer()->SetBackground(1.0, 1.0, 1.0); // Add multiple line plots, setting the colors etc vtkSmartPointer<vtkChartXY> chart = vtkSmartPointer<vtkChartXY>::New(); view->GetScene()->AddItem(chart); vtkPlot *line = chart->AddPlot(vtkChart::LINE); #if VTK_MAJOR_VERSION <= 5 line->SetInput(table, 0, 1); #else line->SetInputData(table, 0, 1); #endif line->SetColor(0, 255, 0, 255); line->SetWidth(3.0); line->GetXAxis()->SetTitle("Max Points Per Region"); line->GetYAxis()->SetTitle("Run time"); //line->GetYAxis()->AutoScale(); //line->GetYAxis()->SetRange(0,0.02); view->GetRenderWindow()->SetMultiSamples(0); // Start interactor view->GetInteractor()->Initialize(); view->GetInteractor()->Start(); return EXIT_SUCCESS; } void RandomPointInBounds(vtkPolyData* polydata, double p[3]) { double bounds[6]; polydata->GetBounds(bounds); double x = bounds[0] + (bounds[1] - bounds[0]) * vtkMath::Random(0.0,1.0); double y = bounds[2] + (bounds[3] - bounds[2]) * vtkMath::Random(0.0,1.0); double z = bounds[4] + (bounds[5] - bounds[4]) * vtkMath::Random(0.0,1.0); p[0] = x; p[1] = y; p[2] = z; } double TimeOBBTree(vtkPolyData* polydata, int maxLevel, int numberOfTrials) { vtkSmartPointer<vtkTimerLog> timer = vtkSmartPointer<vtkTimerLog>::New(); timer->StartTimer(); vtkMath::RandomSeed(0); // this should be changed to time(NULL) to get random behavior // Create the tree vtkSmartPointer<vtkOBBTree> obbTree = vtkSmartPointer<vtkOBBTree>::New(); obbTree->SetDataSet(polydata); obbTree->AutomaticOff(); obbTree->SetMaxLevel(maxLevel); obbTree->BuildLocator(); for(int i = 0; i < numberOfTrials; i++) { double p1[3]; double p2[3]; RandomLineThroughVolume(polydata, p1, p2); double t; double x[3]; double pcoords[3]; int subId; obbTree->IntersectWithLine(p1, p2, .001, t, x, pcoords, subId); } timer->StopTimer(); std::cout << "OBBTree took " << timer->GetElapsedTime() << std::endl; return timer->GetElapsedTime(); } void RandomLineThroughVolume(vtkPolyData* polydata, double p1[3], double p2[3]) { double bounds[6]; polydata->GetBounds(bounds); double p[3]; RandomPointInBounds(polydata, p); double v[3]; RandomDirection(v); double lineP1[3]; double lineP2[3]; for(unsigned int i = 0; i < 3; i++) { p1[i] = p[i] + 1000 * v[i]; p2[i] = p[i] - 1000 * v[i]; } double t1, t2; int plane1, plane2; vtkBox::IntersectWithLine(bounds, lineP1, lineP2, t1, t2, p1, p2, plane1, plane2); } void RandomDirection(double v[3]) { v[0] = vtkMath::Random(0.0,1.0); v[1] = vtkMath::Random(0.0,1.0); v[2] = vtkMath::Random(0.0,1.0); vtkMath::Normalize(v); }
CMakeLists.txt¶
cmake_minimum_required(VERSION 2.8) PROJECT(OBBTreeTimingDemo) find_package(VTK REQUIRED) include(${VTK_USE_FILE}) add_executable(OBBTreeTimingDemo MACOSX_BUNDLE OBBTreeTimingDemo.cxx) target_link_libraries(OBBTreeTimingDemo ${VTK_LIBRARIES})
Download and Build OBBTreeTimingDemo¶
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Click here to download OBBTreeTimingDemo and its CMakeLists.txt file. Once the tarball OBBTreeTimingDemo.tar has been downloaded and extracted,
cd OBBTreeTimingDemo/build
If VTK is installed:
cmake ..
If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:
cmake -DVTK_DIR:PATH=/home/me/vtk_build ..
Build the project:
make
and run it:
./OBBTreeTimingDemo
WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.