PCL Visualizer example: Cannot acquire keyboard and mouse events - c++

Question

I'm following this tutorial in the official PCL documentation for the class PCLVisualizer:
http://pointclouds.org/documentation/tutorials/pcl_visualizer.php
and I'm having troubles with the keyboard acquisition: when I select the render window, where the pointcloud is displayed, and try to press "r" or "q", nothing happens and when I try to press the mouse left button, the following text is displayed:
Left mouse button released at position (413, 475)
and the following error is raised (at runtime):
Assertion failed: (px != 0), function operator->, file /usr/local/include/boost/smart_ptr/shared_ptr.hpp, line 687.
Abort trap: 6
I saw that this kind of error happens when you don't initialize the boost::shared_ptr in the declaration of the variable. But in the code listed in the documentation the variable is well defined, so I suppose that the problem concerns the shared_ptr.hpp library, or it isn't?
I've searched over the Internet for a solution, but I haven't found nothing that could solve the issue.
Is there someone that is capable of acquiring keystrokes in the pointcloud's render window by running it on OS X?
If the question is not clear, please let me know.
Thanks a lot for any help or information!

Answer 1

You do not show any code so it's hard to tell what's wrong in your program.
Here is a working example, tested on Ubuntu 14.04 with PCL latest trunk (VTK trunk):
#include <iostream>
#include <pcl/visualization/pcl_visualizer.h>
void keyboardEventOccurred(const pcl::visualization::KeyboardEvent &event, void* viewer_void)
{
boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer = *static_cast<boost::shared_ptr<pcl::visualization::PCLVisualizer> *>(viewer_void);
if (event.getKeySym() == "r" && event.keyDown())
std::cout << "'r' was pressed" << std::endl;
if (event.getKeySym() == "h" && event.keyDown())
std::cout << "'h' was pressed" << std::endl;
}
void mouseEventOccurred(const pcl::visualization::MouseEvent &event, void* viewer_void)
{
boost::shared_ptr<pcl::visualization::PCLVisualizer> viewer = *static_cast<boost::shared_ptr<pcl::visualization::PCLVisualizer> *>(viewer_void);
if (event.getButton() == pcl::visualization::MouseEvent::LeftButton &&
event.getType() == pcl::visualization::MouseEvent::MouseButtonRelease)
std::cout << "Left mouse button released at position (" << event.getX() << ", " << event.getY() << ")" << std::endl;
}
int main()
{
pcl::visualization::PCLVisualizer::Ptr viewer(new pcl::visualization::PCLVisualizer);
viewer->addCoordinateSystem();
viewer->registerKeyboardCallback(keyboardEventOccurred, (void*)&viewer);
viewer->registerMouseCallback(mouseEventOccurred, (void*)&viewer);
viewer->spin();
}
Note that some key-strokes are already used by the PCL visualizer for some actions (press h for more details), but it does not prevent you from using them as well.