Multiple Isosurfaces with Caps

Mix.install([
  {:plotly_ex, "~> 0.3"},
  {:kino, "~> 0.18"}
])

Section

surface: %{count: N} draws N evenly-spaced isosurfaces between isomin and isomax. caps: %{x: %{show: false}, y: %{show: false}, z: %{show: true}} controls whether the volume is capped at the bounding-box faces. Disabling x and y caps while keeping z creates an open tube-like view of the nested shells.

alias Plotly.{Figure, Isosurface}

n = 20
vals = Enum.map(0..(n - 1), &(&1 / (n - 1) * 4 - 2))

grid = for x <- vals, y <- vals, z <- vals, do: {x, y, z}

xs = Enum.map(grid, &elem(&1, 0))
ys = Enum.map(grid, &elem(&1, 1))
zs = Enum.map(grid, &elem(&1, 2))

values = Enum.map(grid, fn {x, y, z} -> x * x + y * y + z * z end)

Figure.new()
|> Figure.add_trace(
  Isosurface.new(
    x: xs, y: ys, z: zs,
    value: values,
    isomin: 0.5,
    isomax: 4,
    surface: %{count: 4},
    colorscale: "RdBu",
    showscale: true,
    opacity: 0.6,
    caps: %{
      x: %{show: false},
      y: %{show: false},
      z: %{show: true}
    }
  )
)
|> Figure.update_layout(
  title: "Multiple Isosurfaces with Caps",
  scene: %{
    xaxis: %{title: "X"},
    yaxis: %{title: "Y"},
    zaxis: %{title: "Z"}
  }
)
|> Plotly.show()