Draw Box on view and pcplayer

Hi guys, I'm currently working on pointclouds generated from LiDAR sensors. My goal is to detect the object and draw a bounding box around it.

I can calculate the coordinates of the corner points of the bounding box. However, I do not know how can I draw the bounding box dynamically into the pcplayer view that I'm visualizing my pointcloud.

How can I visualize both my pointcloud and also draw the bounding box dynamically on the same view?

Thanks in advance.

This is my code :

veloReader = velodyneFileReader('%pathtomypcapfile%','VLP16');

duration = 150; % seconds %

xlimits = [-60 60];
ylimits = [-60 60];
zlimits = [-5 50];

player = pcplayer(xlimits,ylimits,zlimits);

xlabel(player.Axes,'X (m)');
ylabel(player.Axes,'Y (m)');
zlabel(player.Axes,'Z (m)');

veloReader.CurrentTime = veloReader.StartTime + seconds(0.3); 

while(hasFrame(veloReader) && player.isOpen() && (veloReader.CurrentTime < veloReader.StartTime + seconds(duration)))
    ptCloud = readFrame(veloReader);
    
    cornerpoints = myFunctionToCalculateBoundingBox(ptCloud);
    
    view(player,ptCloud.Location,ptCloud.Intensity);
    pause(0.05);
end

and myFunctionToCalculateBoundingBox returns points as 8x3 matrix :

>> cornerpoints

cornerpoints =

    0.9205   25.9202    5.9978
    0.9655    7.6629    0.1411
    0.2301    7.6634    0.1338
    0.1852   25.9207    5.9905
    0.9206   25.9228    5.9896
    0.9656    7.6655    0.1329
    0.2302    7.6660    0.1256
    0.1853   25.9233    5.9823

[Bram Surewaard]

Hey Mert,

I am looking for the same thing as you and I was wondering if you where able to find a solution?

Thanks!

[Mert Saracoglu]

Hey,

the solution is to use showShape function.

Check out this page : https://www.mathworks.com/help/vision/ref/showshape.html

[Pavan Kumar B N]

@Mert Saracoglu Could you please share some details, how you achieved it?

[Mert Saracoglu]

view(player,ptCloud);
showShape('cuboid',cuboidPosition, ...
    'Parent',player.Axes, ...
    'Color','red', ...
    'Opacity',0.10)
drawnow

Where,

cuboidPosition = [center_x center_y center_z length_x length_y length_z]

I think you can achieve the same thing by tweaking this code snippet.

[Pavan Kumar B N]

@Mert Saracoglu Thank you for sharing!! I am also working on lidar-based object detection and tracking. Could you please provide details/source that how you have achieved? Thank you very much!!

Answer 1

[Aditya Patil]

In R2020b, we have released the Lidar labeler app that will allow you to visualize and label Lidar datasets. You can Get Started with the Lidar Labeler documentation.