用vtk画海量的离散点(此方法用点精灵和glsl)

ttttttttt在无网格法中,画离散点,如果点比较多的话,就不能用小球表示,具我的测试,小球的数量如果超出一百个,速度就慢得无法忍受,解决办法是用点精灵,或者glsl着色语言

#include "vtkCamera.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
#include "vtkInteractorStyleSwitch.h"
#include "vtkPolyData.h"
#include "vtkPointSource.h"
#include "vtkRenderer.h"
#include "vtkElevationFilter.h"
#include "vtkPointSpriteMapper.h"
#include "vtkImageGaussianSource.h"
#include "vtkMath.h"
#include "vtkActor.h"
#include "vtkDebugLeaks.h"
#include "vtkProperty.h"
#include "vtkSmartPointer.h"
#include "vtkPolyData.h"
#include "vtkPoints.h"
#include "vtkCellArray.h"
#include "vtkFloatArray.h"
#include "vtkPointData.h"

// vtk Testing
#include "vtkTestUtilities.h"
#include "vtkRegressionTestImage.h"
#include "vtkSphereSource.h"
#include "vtkAppendPolyData.h"

#include <vtksys/SystemTools.hxx>
#include <vtkstd/string>

//#define SPRITES_ON
//#define SPHERES_ON
#define use_glsl          0
#define use_pointsprites  1

//---------------------------------------------------------------------------
//bool SetEnv(const char* name, const char *val, bool overwrite);
//---------------------------------------------------------------------------
int main( int argc, char *argv[] )
{
 
  //
  // We are loading Shaders from a custom materials repository, tell
  // the vtkXMLShader loading code to search here.
  //
  //SetEnv("USER_MATERIALS_DIRS", ResourceDir.c_str(), true);

  ////////////////////////////////////////////////
  //
  // An array of point sprite sphere glyphs
  //
  ////////////////////////////////////////////////
  const double rows = 10;
  const double numspheres = rows*rows;
  const double Ascaling = 0.1;
  const double Bscaling = 1.0 - Ascaling;

  vtkPolyData* Sprites = vtkPolyData::New();
  vtkPoints*    points = vtkPoints::New();
  vtkCellArray*  verts = vtkCellArray::New();
  vtkFloatArray *sizes = vtkFloatArray::New();

  points->SetNumberOfPoints(numspheres);
  sizes->SetNumberOfTuples(numspheres);
  sizes->SetNumberOfComponents(1);
  verts->Allocate(numspheres,numspheres);
  Sprites->SetPoints(points);
  Sprites->SetVerts(verts);
  sizes->SetName("PointSizes");
  Sprites->GetPointData()->AddArray(sizes);
  //
  for (int y=0; y<rows; y++) {
    for (int x=0; x<rows; x++) {
      vtkIdType Id = y*rows+x;
      points->SetPoint(Id, x, y, 0.0);
      sizes->SetValue(Id, Ascaling + Bscaling*((double)Id/numspheres));
      verts->InsertNextCell(1,&Id);
    }
  }

  //
  // Colour sprites
  //
  vtkElevationFilter* SpriteColour = vtkElevationFilter::New();
  SpriteColour->SetInput(Sprites);
  SpriteColour->SetLowPoint ( 0.0, 0.0, 0.0);
  SpriteColour->SetHighPoint( rows, rows, 0.0);

  vtkPointSpriteMapper *SpriteMapper = vtkPointSpriteMapper::New();
   
    SpriteMapper->SetRenderModeToPointSprite();
    SpriteMapper->SetBlendModeToOcclude();
    SpriteMapper->SetDefaultPointSize(64);
    SpriteMapper->SetQuadraticPointDistanceAttenuation(1.0, 0.1, 0.0);
 
 SpriteMapper->SetParticleImageFileName("D:/aaa.png");
    SpriteMapper->SetParticleImage(NULL);
 SpriteMapper->SetInputConnection(SpriteColour->GetOutputPort());

  // Create actor and set sprite mapper
  vtkActor *SpriteActor = vtkActor::New();
  SpriteActor->SetMapper(SpriteMapper);

  ////////////////////////////////////////////////
  //
  // An array of Spheres to go alongside sprites
  //
  ////////////////////////////////////////////////
  vtkSphereSource *SphereSource = vtkSphereSource::New();
  vtkAppendPolyData *SphereAppend = vtkAppendPolyData::New();
  for (int y=0; y<rows; y++) {
    for (int x=0; x<rows; x++) {
      int Id = y*rows+x;
      SphereSource->SetCenter(x, y, 1.0);
      SphereSource->SetRadius((Ascaling + Bscaling*((double)Id/numspheres))/2.0);
      SphereSource->SetThetaResolution(32);
      SphereSource->SetPhiResolution(16);
      SphereSource->Update();
      vtkPolyData *poly = vtkPolyData::New();
      poly->DeepCopy(SphereSource->GetOutput());
      SphereAppend->AddInput(poly);
      poly->Delete();
    }
  }

  //
  // Colour spheres
  //
  vtkElevationFilter* SphereColour = vtkElevationFilter::New();
  SphereColour->SetInputConnection(SphereAppend->GetOutputPort());
  SphereColour->SetLowPoint ( 0.0, 0.0, 0.0);
  SphereColour->SetHighPoint( rows, rows, 0.0);

  //
  // Polydata mapper
  //
  vtkPolyDataMapper* SphereMapper = vtkPolyDataMapper::New();
  SphereMapper->SetInputConnection(SphereColour->GetOutputPort());

  //
  // SphereMapper actor
  //
  vtkActor* SphereActor = vtkActor::New();
  SphereActor->SetMapper(SphereMapper);

  ////////////////////////////////////////////////
  // setup renderer etc
  ////////////////////////////////////////////////
  vtkRenderer* ren = vtkRenderer::New();
//#ifdef SPRITES_ON
  ren->AddActor(SpriteActor);
//#endif
//#ifdef SPHERES_ON
 // ren->AddActor(SphereActor);
//#endif
  const double distance = 1.75;
  ren->SetBackground(0.0,0.0,0.0);
  ren->GetActiveCamera()->SetPosition(distance*(rows+1.0), distance*(rows+1.0), 0.5);
  ren->GetActiveCamera()->SetFocalPoint(rows/2.0, rows/2.0, 0.5);
  ren->GetActiveCamera()->SetRoll(45.0);
  ren->ResetCameraClippingRange();

  vtkRenderWindow* renWin = vtkRenderWindow::New();
  renWin->SetSize(512, 512);
  renWin->AddRenderer(ren);

  vtkRenderWindowInteractor* iren = vtkRenderWindowInteractor::New();
  iren->SetRenderWindow(renWin);
  vtkInteractorStyleSwitch *is = vtkInteractorStyleSwitch::New();
  iren->SetInteractorStyle(is);
  is->SetCurrentStyleToTrackballCamera();

  renWin->Render();

    iren->Start();
 

 
  return 1;
}