Here is the code : http://www.3rdm.biz/files/OSG_DelaunayTest.cpp
Or cut and paste :
Code:
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgUtil/SmoothingVisitor>
#include <osgUtil/DelaunayTriangulator>
#include <osgDB/WriteFile>
#include <iostream>
#include <algorithm>
using namespace std;
//
________________________________________________________________________________________________
// Generate a gaussian pseudo-random number
double FastAndDirtyGaussianRandomNumber( double sequenceMean, double
sequenceSigma )
{
double u = ( static_cast<double>( rand() ) /
static_cast<double>(RAND_MAX))*2.0 - 1.0;
double v = ( static_cast<double>( rand() ) /
static_cast<double>(RAND_MAX))*2.0 - 1.0;
double r = u*u + v*v;
if ( r==0 || r>1 )
{
return FastAndDirtyGaussianRandomNumber( sequenceMean, sequenceSigma );
}
double c = sqrt( -2.0*log(r)/r );
return sequenceMean + sequenceSigma*( u*c );
}
struct GaussianRandomSeq
{
double mMean, mSigma;
GaussianRandomSeq( double sequenceMean, double sequenceSigma, unsigned int
randomSeed)
: mMean( sequenceMean ), mSigma( sequenceSigma )
{
srand( randomSeed );
}
double operator() () { return FastAndDirtyGaussianRandomNumber( mMean,
mSigma ); }
};
//
________________________________________________________________________________________________
// Main
int main( int argc, const char** pArgv )
{
// Smoothing has the effect of softening the abberation (Linux). Turn smoothing
off to see the
// abberation even better
bool doSmoothing = false;
// Define surface sizes
size_t dimension = 256;
unsigned int rows=dimension, cols=dimension;
unsigned int size = rows * cols;
// Create elevation map as a gaussian random surface
cout << "Create points ...... " << endl;
osg::ref_ptr<osg::Vec3Array> rPoints = new osg::Vec3Array( size );
unsigned int seed = 7993;
double mean = 0.0, sigma=0.5;
GaussianRandomSeq randSeq( mean, sigma, seed );
std::vector<double> elevationData( rows*cols );
std::generate( elevationData.begin(), elevationData.end(), randSeq );
// Create 3D points using the elevation map
unsigned pointIndex = 0;
for( unsigned i=0; i<rows; i++ )
{
float y = static_cast<double>( i );
for( unsigned j=0; j<cols; j++ )
{
float x = static_cast<double>( j );
float z = elevationData[pointIndex];
(*rPoints).at( pointIndex++ ) = osg::Vec3( x, y, z );
}
}
// Create geometry with a triangulator
cout << "Triangulate ...... " << endl;
osg::ref_ptr<osg::Geometry> rGeom = new osg::Geometry;
osg::ref_ptr<osgUtil::DelaunayTriangulator> triangulator =
new osgUtil::DelaunayTriangulator( rPoints );
triangulator->setOutputNormalArray( new osg::Vec3Array() );
triangulator->triangulate();
rGeom->addPrimitiveSet( triangulator->getTriangles() );
rGeom->setVertexArray( triangulator->getInputPointArray() );
rGeom->setNormalArray( triangulator->getOutputNormalArray() );
rGeom->setNormalBinding( osg::Geometry::BIND_PER_PRIMITIVE );
rGeom->setTexCoordArray( 0, new osg::Vec2Array( size ) );
// Colorize uniformly
cout << "Post prep ...... " << endl;
osg::ref_ptr<osg::Vec4Array> rColors = new osg::Vec4Array();
osg::Vec4 color( 1, 1, 1, 1 );
rColors->push_back( color );
rGeom->setColorArray( rColors );
rGeom->setColorBinding( osg::Geometry::BIND_OVERALL );
// Smooth the geometry
if ( doSmoothing )
{
osgUtil::SmoothingVisitor smoother;
smoother.smooth( *rGeom );
}
// Create geode and save to disk
osg::ref_ptr<osg::Geode> rGeode = new osg::Geode();
rGeode->addDrawable( rGeom );
cout << "Write 'Triangulated.osg' ...... " << endl;
osgDB::writeNodeFile( *rGeode.get(), "Triangulated.osg" );
// Create scene graph and add geometry
osg::ref_ptr<osg::Group> rSceneGraph = new osg::Group();
rSceneGraph->addChild( rGeode );
// Setup viewer and run
osgViewer::Viewer viewer;
viewer.setSceneData( rSceneGraph );
viewer.addEventHandler( new osgViewer::StatsHandler() );
return viewer.run();
}
------------------------
things are more like they are now than they have ever been before
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=58085#58085
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