function drawFace( me, face, primary, secondary, planeIdx, line1, line2, drawMinFace, cond2, cond3 ) {
    // if this face is visible, draw it
    if( ( me.Min[primary] < me.Max[primary] ) && ( me.Min[secondary] < me.Max[secondary] ) ) {
        var world3D = new Vector( 0,0,0 );
        
        world3D[face]        = drawMinFace ? me.Min[face] : me.Max[face];
        world3D[primary]     = me.Min[primary];
        world3D[secondary]   = me.Min[secondary];
        var screen2D = me.Parent.ScreenPos( world3D );
        // calculate and construct Bbox rectangle path
        ss = "M " + screen2D.x + " " + screen2D.y + " "; // move to corner 1

        world3D[primary] = me.Max[primary];
        screen2D = me.Parent.ScreenPos( world3D );
        ss += "L " + screen2D.x + " " + screen2D.y + " "; // line to corner 2

        world3D[secondary] = me.Max[secondary];
        screen2D = me.Parent.ScreenPos( world3D );
        ss += "L " + screen2D.x + " " + screen2D.y + " "; // line to corner 3

        world3D[primary] = me.Min[primary];
        screen2D = me.Parent.ScreenPos( world3D );
        ss += "L " + screen2D.x + " " + screen2D.y + " z"; // line to corner 4 and close back to corner 1

        me.Plane[planeIdx].setAttribute( "d", ss );  // [d]efine the path for this panes Bbox

        world3D[face] = 1; world3D[primary] = 0; world3D[secondary] = 0;

        // and set its attributes
        me.Plane[planeIdx].setAttribute( "fill", me.Parent.GetColor( me.FillColor, me.FillColor, world3D, drawMinFace ? me.Min : me.Max ) );
        me.Plane[planeIdx].setAttribute( "stroke", me.StrokeColor );
        me.Plane[planeIdx].setAttribute( "stroke-width", me.StrokeWeight );
        me.Plane[planeIdx].setAttribute( "visibility", "visible" );

        world3D[face] = drawMinFace ? me.Min[face] : me.Max[face];

        // Draw the horizontal and vertical grid lines on this Bbox face
        drawGrid( me, face, primary, secondary, line1, cond3, cond2, world3D ); // horizontal
        drawGrid( me, face, secondary, primary, line2, cond2, cond3, world3D ); // vertical
    }
    else { // else hide it.
        me.Plane[planeIdx].setAttribute( "visibility", "hidden" );
        for( var ii = 0; ii < 11; ii++ ) me.Line[line1][ii].setAttribute( "visibility", "hidden" );
        for( var ii = 0; ii < 11; ii++ ) me.Line[line2][ii].setAttribute( "visibility", "hidden" );
    }
}