How does the point cloud rendered by vtkPolyData interact with each point?

Web
7

Hello, I tried this example vtk.js. I call the method by click event, but not every click will trigger, even if I click the point.

document.addEventListener('mousedown', (event) => {
    const [x, y] = eventToWindowXY(event);
    hardwareSelector.getSourceDataAsync(renderer, x, y, x, y).then((result) => {
      console.log(result);
      if (result) {
        processSelections(result.generateSelection(x, y, x, y));
      } else {
        processSelections(null);
      }
    });
});

function processSelections(selections) {
    if (!selections || selections.length === 0) {
      return;
    }

    const {
      worldPosition: rayHitWorldPosition,
      compositeID,
      prop,
      propID,
      attributeID,
    } = selections[0].getProperties();

    console.log(selections);
    console.log(selections[0].getProperties());
    console.log(hardwareSelector.getFieldAssociation());
    if (hardwareSelector.getFieldAssociation() === FieldAssociations.FIELD_ASSOCIATION_POINTS) {
      // Selecting points
      console.log('attributeID', attributeID);
    }
    renderWindow.render();
  }

Can you help me see why this happens?