Understanding FaceGrids

Question

I'm having difficulties with FaceGrids. This should be pretty basic, but the documentation isn't helpfull with its fancy and mostly useless examples (again!)

I just want to add 2 lines on the middle of each of the 6 faces of the bounding box.

Here's a MWE showing 6 lines on two faces :

ParametricPlot3D[{t Cos[6 t], Sin[4 t], t}, {t, 0, 2 Pi},
    PlotRange -> {{-1, 1}, {-1, 1}, {-1, 1}},
    Boxed -> True,
    BoxStyle -> Directive[GrayLevel[0.8]],
    FaceGrids -> {{0, 0, 1}, {0, 0, -1}}, (* How to make sense of this ? *)
    FaceGridsStyle -> Directive[LightGray, Dashed],
    AxesOrigin -> {0, 0, 0},
    Ticks -> True,
    Lighting -> "Neutral",
    SphericalRegion -> True,
    Method -> {"RotationControl" -> "Globe"},
    ImageSize -> {700, 700}
]

Six face lines is too much. I need only two lines, on the middle of each of the 6 faces of the cube.

Answer 1

I think I got it. Is there a simpler way of doing this ?

FaceGrids -> {
    {{1, 0, 0}, {{0}, {0}}},
    {{-1, 0, 0}, {{0}, {0}}},
    {{0, 1, 0}, {{0}, {0}}},
    {{0, -1, 0}, {{0}, {0}}},
    {{0, 0, 1}, {{0}, {0}}},
    {{0, 0, -1}, {{0}, {0}}}
 }

Unless there's a simpler way of doing this (?), here's a nice alternative to the reference box :

ParametricPlot3D[{t Cos[6 t], Sin[4 t], t}, {t, 0, 2 Pi}, 
    PlotRange -> {{-1, 1}, {-1, 1}, {-1, 1}}, Boxed -> True, 
    BoxStyle -> Directive[GrayLevel[1]],
    FaceGrids -> {
        {{1, 0, 0}, {{0}, {0}}},
        {{-1, 0, 0}, {{0}, {0}}},
        {{0, 1, 0}, {{0}, {0}}},
        {{0, -1, 0}, {{0}, {0}}},
        {{0, 0, 1}, {{0}, {0}}},
        {{0, 0, -1}, {{0}, {0}}}
    },
    FaceGridsStyle -> Directive[Gray, Dotted],
    AxesOrigin -> {0, 0, 0},
    Ticks -> True,
    SphericalRegion -> True,
    Method -> {"RotationControl" -> "Globe"},
    ImageSize -> {700, 700}
]

Preview :