docs: public double process(Point2D_F64 a , Point2D_F64 b , Se3_F64 a_to_b ,
  						  Point3D_F64 Xa )
  	{
  		PerspectiveOps.convertNormToPixel(intrinsicA,a.x,a.y,pixelN);
  		PerspectiveOps.convertNormToPixel(intrinsicA,Xa.x/Xa.z, Xa.y/Xa.z,pixelX);
  
  		double error = pixelN.distance2(pixelX);
  
  		a_to_b.transform(Xa,Xb);
  		PerspectiveOps.convertNormToPixel(intrinsicB,b.x,b.y,pixelN);
  		PerspectiveOps.convertNormToPixel(intrinsicB,Xb.x/Xb.z, Xb.y/Xb.z,pixelX);
  
  
  		return (error + pixelN.distance2(pixelX))/2;
  	}