question: public double normalDistance ( final double x , final double y , final double z , final Membership ... bounds ) { final double dist = evaluate ( x , y , z ) ; final double perpX = x - dist * this . x ; final double perpY = y - dist * this . y ; final double perpZ = z - dist * this . z ; if ( ! meetsAllBounds ( perpX , perpY , perpZ , bounds ) ) { return Double . POSITIVE_INFINITY ; } return Math . abs ( dist ) ; }
target:  Compute normal distance from plane to a vector.