// Define the id of your board in BOARDID
var board = JXG.JSXGraph.initBoard(BOARDID, {
boundingbox: [-8, 8, 8, -8],
keepaspectratio: false,
axis: false
});
var view = board.create('view3d',
[
[-6, -3],
[8, 8],
[
[-5, 5],
[-5, 5],
[-5, 5]
]
], {});
var b = board.create('slider', [[-7, -6], [5, -6], [-3, 2, 4]], {name: 'b'});
// Klein bottle
var c = view.create('parametricsurface3d', [
(u, v) => b.Value() * (1 - Math.sin(u)) * Math.cos(u) + (2 - Math.cos(u)) * Math.cos(v) * (2 * Math.exp(-Math.pow(u / 2 - Math.PI, 2)) - 1),
(u, v) => (2 - Math.cos(u)) * Math.sin(v),
(u, v) => 4 * Math.sin(u) + 0.5 * (2 - Math.cos(u)) * Math.sin(u) * Math.cos(v) * Math.exp(-Math.pow(u - 3 * Math.PI / 2, 2)),
[0, 2 * Math.PI],
[0, 2 * Math.PI],
], {
strokeColor: 'green',
stepsU: 60,
stepsV: 60
});