Function convert

src/traces/streamtube/convert.js:80–186

(scene, trace)

}

function convert(scene, trace) {
    var sceneLayout = scene.fullSceneLayout;
    var dataScale = scene.dataScale;
    var len = trace._len;
    var tubeOpts = {};

    function toDataCoords(arr, axisName) {
        var ax = sceneLayout[axisName];
        var scale = dataScale[axisName2scaleIndex[axisName]];
        return Lib.simpleMap(arr, function(v) { return ax.d2l(v) * scale; });
    }

    tubeOpts.vectors = zip3(
        toDataCoords(trace._u, 'xaxis'),
        toDataCoords(trace._v, 'yaxis'),
        toDataCoords(trace._w, 'zaxis'),
        len
    );

    // Over-specified mesh case, this would error in tube2mesh
    if(!len) {
        return {
            positions: [],
            cells: []
        };
    }

    var meshx = toDataCoords(trace._Xs, 'xaxis');
    var meshy = toDataCoords(trace._Ys, 'yaxis');
    var meshz = toDataCoords(trace._Zs, 'zaxis');

    tubeOpts.meshgrid = [meshx, meshy, meshz];
    tubeOpts.gridFill = trace._gridFill;

    var slen = trace._slen;
    if(slen) {
        tubeOpts.startingPositions = zip3(
            toDataCoords(trace._startsX, 'xaxis'),
            toDataCoords(trace._startsY, 'yaxis'),
            toDataCoords(trace._startsZ, 'zaxis')
        );
    } else {
        // Default starting positions:
        //
        // if len>2, cut xz plane at min-y,
        // takes all x/y/z pts on that plane except those on the edges
        // to generate "well-defined" tubes,
        //
        // if len=2, take position halfway between two the pts,
        //
        // if len=1, take that pt
        var sy0 = meshy[0];
        var sx = getDfltStartingPositions(meshx);
        var sz = getDfltStartingPositions(meshz);
        var startingPositions = new Array(sx.length * sz.length);
        var m = 0;

        for(var i = 0; i < sx.length; i++) {