void PCANormalEstimator::estimateNormals(vtkPolyData* data, double neighRadius)
{
vtkPointLocator* locator = vtkPointLocator::New();
locator->SetDataSet(data);
locator->BuildLocator();
int i, numOfPoints = data->GetNumberOfPoints();
vtkDoubleArray* normals = vtkDoubleArray::New();
normals->SetNumberOfComponents(3);
normals->SetNumberOfTuples(numOfPoints);
PCA pca;
double p[3], com[3], eigenvals[3], eigenvecs[3][3];
vtkPoints* points = data->GetPoints();
vtkIdList* neighs = vtkIdList::New();
for ( i = 0 ; i < numOfPoints ; ++i )
{
points->GetPoint(i, p);
neighs->Reset();
locator->FindPointsWithinRadius(neighRadius, p, neighs);
if ( neighs->GetNumberOfIds() < 3 )
{
normals->SetTuple3(i, 0.0, 0.0, 0.0);
continue;
}
// Perform PCA
pca.doPCA(points, neighs, eigenvecs, eigenvals, com);
// Save the normal
normals->SetTuple3(i, eigenvecs[0][2], eigenvecs[1][2], eigenvecs[2][2]);
}
data->GetPointData()->SetNormals(normals);
// Clean up
locator->Delete();
normals->Delete();
neighs->Delete();
}
