自定义点击，如何高效判断点击的点为点云的点呢

//鼠标左键--回调事件
private void TrackballStyle_LeftButtonPressEvt(vtkObject sender, vtkObjectEventArgs e)
{
// 获取鼠标点击位置
vtkRenderWindow renWin = renderWindowControl1.RenderWindow; //指定渲染窗口
int[] clickPos = renWin.GetInteractor().GetEventPosition();
// 拾取
picker.Pick(clickPos[0], clickPos[1], 0.0, render);
double[] worldPos = picker.GetPickPosition();
//
foreach (var item in worldPos)
{
richTextBox1.Text += item.ToString("f2") + ",";
}
richTextBox1.Text += "\n";