Best way to render a collection of isloated lines

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1

Hello,

I am trying to render some isolated lines in vtk js. I have a collection of point pairs, each of which I would like to connect with lines.

The only example I have seen is something like the following;

  const pointPolydata = vtkPolyData.newInstance();
  pointPolydata.getPoints().setData(Float32Array.from(points), 3);
  const lines = new Uint32Array(points.length + 1);
  for (let i = 0; i < points.length; i++) {
    lines[i] = i;
  }

  pointPolydata.getLines().setData(lines);

However what I end up with is one line connecting all of the points, which is not what I want.

I could repeat the above for each of the point pairs, but I believe that would require adding multiple actors to the scene, which feels like overkill?

Any help would be much appreciated

Thanks

2

You can get your isolated lines by specifying several line cells. For instance, the below code draws lines between point indices (0,1), (2,3), and (4,5). A single line is of the form 2, <startPtIdx>, <endPtIdx>.

polyData.getLines().setData([
  2, 0, 1,
  2, 2, 3
  2, 4, 5
])