Use vtk.js to render point clouds, why dynamically update one point will not display normally, update two or more points can display normally

Here’s an example:

const points = vtkPoints.newInstance();
const polyData= vtkPolyData.newInstance();
const polyDataActor = vtkActor.newInstance();

polyData.setPoints(points);

sphereSource = vtkSphereSource.newInstance({
    radius: 0.25,
    phiResolution: 10,
    thetaResolution: 10,
});

polyDataMapper = vtkGlyph3DMapper.newInstance({
    orient: false, 
    scaling: false, 
    scaleMode: vtkGlyph3DMapper.ScaleModes.SCALE_BY_CONSTANT,
});

polyDataMapper.setInputData(polyData, 0);
polyDataMapper.setInputConnection(sphereSource.getOutputPort(), 1);

polyDataActor.setMapper(polyDataMapper);
polyDataActor.getProperty().setPointSize(5);

points.insertNextPoint([435,50,180]);

points.dataChange();
polyData.modified();

renderWindow.render();

Why can’t the point be rendered when dynamically adding a point? When dynamically adding two points, it can be rendered normally.

points.insertNextPoint([435,50,180]);
points.insertNextPoint([438,50,181]);

There is another question, why not render the out-point cloud when the z coordinate value of multiple points is the same, only add 0.00001 to the z value of a point to render the out-point cloud:

points.insertNextPoint([435,50,180]);
points.insertNextPoint([438,50,180]);

Does anyone pay attention to this problem? When the z coordinate of the point cloud is the same, the point cloud will always fail to render

Have you managed to solve this issue? I’m facing the same problem, and I’d really appreciate any advice you could share if you’ve figured it out.

Does using the native TypedArray api solve the issue? I mean calling points.setData(typedArray, 3)?