message: STYLE: Displaced Detector Filter variables name
  Changed instances sdd to sid and invsdd to invsid for consistency in the variable naming.
diff: @@ -247,14 +247,14 @@ DisplacedDetectorImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerate
  {
  // Prepare weights for current slice (depends on ProjectionOffsetsX)
  const double sx = m_Geometry->GetSourceOffsetsX()[itIn.GetIndex()[NDimension - 1]];
  - double sdd = m_Geometry->GetSourceToIsocenterDistances()[itIn.GetIndex()[NDimension - 1]];
  - sdd = sqrt(sdd * sdd + sx * sx); // To untilted situation
  - double invsdd = 0.;
  + double sid = m_Geometry->GetSourceToIsocenterDistances()[itIn.GetIndex()[NDimension - 1]];
  + sid = sqrt(sid * sid + sx * sx); // To untilted situation
  + double invsid = 0.;
  double invden = 0.;
  - if (sdd != 0.)
  + if (sid != 0.)
  {
  - invsdd = 1. / sdd;
  - invden = 1. / (2. * std::atan(theta * invsdd));
  + invsid = 1. / sid;
  + invden = 1. / (2. * std::atan(theta * invsid));
  }
  typename WeightImageType::PointType point;
  weights->TransformIndexToPhysicalPoint(itWeights.GetIndex(), point);
  @@ -270,7 +270,7 @@ DisplacedDetectorImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerate
  else if (l >= theta)
  itWeights.Set(2.0);
  else
  - itWeights.Set(sin(itk::Math::pi * atan(l * invsdd) * invden) + 1);
  + itWeights.Set(sin(itk::Math::pi * atan(l * invsid) * invden) + 1);
  ++itWeights;
  point[0] += spacing[0];
  }
  @@ -285,7 +285,7 @@ DisplacedDetectorImageFilter<TInputImage, TOutputImage>::DynamicThreadedGenerate
  else if (l >= theta)
  itWeights.Set(0.0);
  else
  - itWeights.Set(1 - sin(itk::Math::pi * atan(l * invsdd) * invden));
  + itWeights.Set(1 - sin(itk::Math::pi * atan(l * invsid) * invden));
  ++itWeights;
  point[0] += spacing[0];
  }
  