code: double triangulationAngle( Point2D_F64 normA , Point2D_F64 normB , Se3_F64 a_to_b ) {
  		// the more parallel a line is worse the triangulation. Get rid of bad ideas early here
  		arrowA.set(normA.x,normA.y,1);
  		arrowB.set(normB.x,normB.y,1);
  		GeometryMath_F64.mult(a_to_b.R,arrowA,arrowA); // put them into the same reference frame
  
  		return UtilVector3D_F64.acute(arrowA,arrowB);
  	}
docs: Computes the acture angle between two vectors. Larger this angle is the better the triangulation
  of the features 3D location is in general