lloyd_smoother_test.cpp

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#include "moab/Core.hpp"
#include "moab/LloydSmoother.hpp"
#include "moab/CartVect.hpp"
#include "TestUtil.hpp"
 
std::string filename = TestDir + "unittest/surfrandomtris-4part.h5m";
 
using namespace moab;
 
int main( int argc, char** argv )
{
 if( argc > 1 ) filename = std::string( argv[1] );
 Core mb;
 ErrorCode rval = mb.load_file( filename.c_str() );CHECK_ERR( rval );
 
 Range elems;
 rval = mb.get_entities_by_dimension( 0, 3, elems );CHECK_ERR( rval );
 if( elems.empty() )
 {
 rval = mb.get_entities_by_dimension( 0, 2, elems );CHECK_ERR( rval );
 }
 if( elems.empty() )
 {
 std::cout << "Mesh must have faces or regions for this test." << std::endl;CHECK_ERR( MB_FAILURE );
 }
 
 // get the vertex positions and set on an intermediate tag, to test smoothing for
 // a tag instead of for coords
 Tag ctag;
 rval = mb.tag_get_handle( "vcentroid", 3, MB_TYPE_DOUBLE, ctag, MB_TAG_CREAT | MB_TAG_DENSE );CHECK_ERR( rval );
 Range verts;
 rval = mb.get_entities_by_dimension( 0, 0, verts );CHECK_ERR( rval );
 std::vector< double > coords( 3 * verts.size() );
 rval = mb.get_coords( verts, &coords[0] );CHECK_ERR( rval );
 rval = mb.tag_set_data( ctag, verts, &coords[0] );CHECK_ERR( rval );
 
 LloydSmoother ll( &mb, NULL, elems, ctag );
 ll.report_its( 10 );
 rval = ll.perform_smooth();CHECK_ERR( rval );
 std::cout << "Mesh smoothed in " << ll.num_its() << " iterations." << std::endl;
 
 // now, set vertex coords to almost their converged positions, then re-smooth; should take fewer
 // iterations
 std::vector< double > new_coords( 3 * verts.size() );
 rval = mb.tag_get_data( ctag, verts, &new_coords[0] );CHECK_ERR( rval );
 unsigned int i;
 Range::iterator vit;
 for( vit = verts.begin(), i = 0; vit != verts.end(); ++vit, i += 3 )
 {
 CartVect old_pos( &coords[i] ), new_pos( &new_coords[i] );
 CartVect almost_pos = old_pos + .99 * ( new_pos - old_pos );
 almost_pos.get( &new_coords[i] );
 }
 rval = mb.set_coords( verts, &new_coords[0] );CHECK_ERR( rval );
 
 LloydSmoother ll2( &mb, NULL, elems );
 ll2.report_its( 10 );
 rval = ll2.perform_smooth();CHECK_ERR( rval );
 std::cout << "Mesh smoothed in " << ll2.num_its() << " iterations." << std::endl;
}