PCLVisualizer point picking weirdness

I am noticing a weird behavior with point picking in PCLVisualizer. For some clicks, it returns the correct x,y,z coordinates. But, some times, the returned coordinate values are not at all in the area I am clicking; they are way off. Any idea why this could be happening?

I don't expect this to be related to the NaN issue because (a) I am not using the point index in the PointPickingEvent. Instead, I am just using the x,y,z values provided by the getPoint method of the event. (b) The point cloud I am rendering doesn't have NaN values.

I did notice that whenever the returned coordinates are wrong, the corresponding point index in the PointPickingEvent is a single digit incorrect value such as 0, 1, 3 etc. But, as I said, I am not using the point index value.

Once in a while, it returns coordinate values so incorrect that the reported pick point is not even within the bounding box of the point cloud.

PCL version: 1.10.1 on Windows 10
Number of points in the cloud: About 4 million

Thanks.

Start by reproducing the PCLVisualizer point-picking behavior on Windows 10 with PCL 1.10.1 and a roughly 4-million-point cloud. Compare PointPickingEvent::getPoint coordinates and the reported point index for clicks that return incorrect values, including points outside the cloud bounding box. Done means identifying and documenting the cause of the incorrect coordinates, with a reliable reproduction or regression check.