Method SetNormal

Filters/Sources/vtkPlaneSource.cxx:199–235

------------------------------------------------------------------------------ Set the normal to the plane. Will modify the Origin, Point1, and Point2 instance variables as necessary (i.e., rotate the plane around its center).

// Set the normal to the plane. Will modify the Origin, Point1, and Point2
// instance variables as necessary (i.e., rotate the plane around its center).
void vtkPlaneSource::SetNormal(double N[3])
{
  double n[3], rotVector[3], theta;

  // make sure input is decent
  n[0] = N[0];
  n[1] = N[1];
  n[2] = N[2];
  if (vtkMath::Normalize(n) == 0.0)
  {
    vtkErrorMacro(<< "Specified zero normal");
    return;
  }

  // Compute rotation vector using a transformation matrix.
  // Note that if normals are parallel then the rotation is either
  // 0 or 180 degrees.
  double dp = vtkMath::Dot(this->Normal, n);
  if (dp >= 1.0)
  {
    return; // zero rotation
  }
  else if (dp <= -1.0)
  {
    theta = 180.0;
    rotVector[0] = this->Point1[0] - this->Origin[0];
    rotVector[1] = this->Point1[1] - this->Origin[1];
    rotVector[2] = this->Point1[2] - this->Origin[2];
  }
  else
  {
    vtkMath::Cross(this->Normal, n, rotVector);
    theta = vtkMath::DegreesFromRadians(acos(dp));
  }

  this->Rotate(theta, rotVector);
}

//------------------------------------------------------------------------------
// Set the normal to the plane. Will modify the Origin, Point1, and Point2