Point cloud visualizer does not work properly - c++

Question

I run the point cloud visualizer simpleVis from the code given in the official docu (see
here.)
Below you find a shortened version of the code.
#include <iostream>
#include <thread>
#include <pcl/common/common_headers.h>
#include <pcl/features/normal_3d.h>
#include <pcl/io/pcd_io.h>
#include <pcl/visualization/pcl_visualizer.h>
#include <pcl/console/parse.h>
using namespace std::chrono_literals;
pcl::visualization::PCLVisualizer::Ptr simpleVis (pcl::PointCloud<pcl::PointXYZ>::ConstPtr cloud)
{
// --------------------------------------------
// -----Open 3D viewer and add point cloud-----
// --------------------------------------------
pcl::visualization::PCLVisualizer::Ptr viewer (new pcl::visualization::PCLVisualizer ("3D Viewer"));
viewer->setBackgroundColor (0, 0, 0);
viewer->addPointCloud<pcl::PointXYZ> (cloud, "sample cloud");
viewer->setPointCloudRenderingProperties (pcl::visualization::PCL_VISUALIZER_POINT_SIZE, 1, "sample cloud");
viewer->addCoordinateSystem (1.0);
viewer->initCameraParameters ();
return (viewer);
}
// --------------
// -----Main-----
// --------------
int
main (int argc, char** argv)
{
// ------------------------------------
// -----Create example point cloud-----
// ------------------------------------
pcl::PointCloud<pcl::PointXYZ>::Ptr basic_cloud_ptr (new pcl::PointCloud<pcl::PointXYZ>);
pcl::PointCloud<pcl::PointXYZRGB>::Ptr point_cloud_ptr (new pcl::PointCloud<pcl::PointXYZRGB>);
std::cout << "Generating example point clouds.\n\n";
// We're going to make an ellipse extruded along the z-axis. The colour for
// the XYZRGB cloud will gradually go from red to green to blue.
std::uint8_t r(255), g(15), b(15);
for (float z(-1.0); z <= 1.0; z += 0.05)
{
for (float angle(0.0); angle <= 360.0; angle += 5.0)
{
pcl::PointXYZ basic_point;
basic_point.x = 0.5 * std::cos (pcl::deg2rad(angle));
basic_point.y = sinf (pcl::deg2rad(angle));
basic_point.z = z;
basic_cloud_ptr->points.push_back(basic_point);
pcl::PointXYZRGB point;
point.x = basic_point.x;
point.y = basic_point.y;
point.z = basic_point.z;
std::uint32_t rgb = (static_cast<std::uint32_t>(r) << 16 |
static_cast<std::uint32_t>(g) << 8 | static_cast<std::uint32_t>(b));
point.rgb = *reinterpret_cast<float*>(&rgb);
point_cloud_ptr->points.push_back (point);
}
if (z < 0.0)
{
r -= 12;
g += 12;
}
else
{
g -= 12;
b += 12;
}
}
basic_cloud_ptr->width = basic_cloud_ptr->size ();
basic_cloud_ptr->height = 1;
point_cloud_ptr->width = point_cloud_ptr->size ();
point_cloud_ptr->height = 1;
pcl::visualization::PCLVisualizer::Ptr viewer;
viewer = simpleVis(basic_cloud_ptr);
while (!viewer->wasStopped ())
{
viewer->resetCamera();
viewer->spinOnce (100);
std::this_thread::sleep_for(100ms);
}
}
Consequently, a window pops up which should visualize the point cloud.
However, I only see green, red and black areas as in the image below.
Then I press r and the following appears:
As far as I understand it, the appearing object is the point cloud.
Now, if I try to move it around. The point cloud "smears" as shown the image below.
I figured the following out:
If I run the simpler cloud viewer as described
here.
The visualisation works properly.
In the last few months, I tried to run a Python library for point cloud visualization that also uses
PCL under the hood. The problem also appears there.
Do you have any idea what the problem is?

Answer 1

This is a deep zoom-in of the meeting of the axes at (0,0,0).
To see more of the point cloud, you need to zoom-out (roll the mouse wheel).
Zoom-out may be limited depending on the definition of focus and the point of view.
Pressing the 'f' key when the mouse cursor hovers over the center will usually take you far enough away to zoom out.
Once you have a reasonable view, you can press 'c' to get (in the stdout) the camera parameters and set them in the code.