int window_width = camera.window_size;
int window_height = camera.window_size;
The above code snippet stacks them but the second PCLVisualizer is
overlapping with first PCLVisualizer little bit. In other words, the second
PCLVisualizer is hiding the bottom of first PCLVisualizer.
I suspect that I need to add the height of title bar in the window_height
parameter. Any suggestions, please?