How do I export Point Cloud Data (Project Tango)?

Question

Just got a Project Tango Development Kit tablet and have worked through some of the demos and examples.

Some older blog posts use the log files from a "Tango Mapper" application that should be preloaded on the device.

• Interactive Visualization of Google Project Tango Data with ParaView
• Ologic Announces integration between ROS and Project Tango
• Google Tango and ROS integration at Bosch
• Mapping Hints and Tips

Unfortunately, the "Tango Mapper" application did not come preloaded on my device and I can't seem to find it on the Play Store.

Is there some other method to simply export or retrieve the PointCloud data for downstream rendering?

[Model number: yellowstone, Tango Core Version: 1.1:2014.11.14-bernoulli-release]

Surfbird

Answer 1

Tango Mapper is an internal tool, and it's currently not public to developers. I think the best way to log the point cloud data is using the c or java example code provided, and maybe do some small modification to log the data to a file.

c example: https://github.com/googlesamples/tango-examples-c

java example: https://github.com/googlesamples/tango-examples-java

Cocainize

Thanks. Was already doing that, but wanted to make sure there wasn't an easier method – Surfbird

Ok, but you normally want to also do tracking if you want to export a proper pointcloud, not just log the distances – Affairs

Answer 2

Not sure if you ever got to solve this, but I was able to find the APK along with a method to export using Tango updated tablet version. I successfully exported the point cloud data using the method described in this blog.

http://www.kitware.com/blog/home/post/838

Edit

Procedure download the APK or use the source code found found in the GITHUB project folder.

Once that is done boot up the app as you normally would. There will a slider record, and auto. If you slide record it will only wait until you hit the snap shot button to record the point cloud data you are currently viewing.

If you slide the auto it will continuously record the point cloud data and create files as it tracks where you are moving. Keep in mind the larger the file the larger it takes to save as a zip.

Once done slide the record and it will prompt you to save and send.

I find it easier to save to the Google Drive as other the other methods sometimes fail to send.

Once done download the free Paraview App found http://www.paraview.org/download/ load up your Point cloud data.

It should be two files one your pose data and the other point cloud. (you could individually load each data using the collapse arrow you see before importing it in.)

That will be it you will be able to see your data and actually play back the animation of you recording it because of your pose data collected.

( only wrote this out because you were looking for an easier way to export data) This is probably the easiest. You could take said data and begin to reconstructed the room based on the pose data collected.)

all credit for source code and tutorial goes to the The Kitware blog

If links are broken DM me and I will send the file to you.

APK is found here

APK DOWNLOAD

they also have listed their source code at the bottom of the blog. It is based on the tango Explorer found in the app store.

Arbutus

You should describe the linked procedure in your answer as well; one day the link may go broken, but your answer should still be available here. – Misbeliever

Answer 3

Sparse mapping: https://www.youtube.com/watch?v=x5C_HNnW_3Q

More indoor mapping: https://www.youtube.com/watch?v=3BNOsxMZD14

It appears that more than a few of the contributors to the Tango project were hired or bought by google. As an example most of the links to code and/or articles by Hidof are MIA, only a facebook page with few clues remains. The internet archive's wayback machine has a few snapshots of their website for the curious.

Weintrob

Answer 4

Go take a look at the Java Point Cloud sample on GitHub - The function you want to look at is onXyzIsAvailable in PointCloudActivity. Extracting a few relevant lines....

public void onXyzIjAvailable(final TangoXyzIjData xyzIj) {
....
               byte[] buffer = new byte[xyzIj.xyzCount * 3 * 4];
               FileInputStream fileStream = new FileInputStream(
                        xyzIj.xyzParcelFileDescriptor.getFileDescriptor());
                try {
                    fileStream.read(buffer,
                            xyzIj.xyzParcelFileDescriptorOffset, buffer.length);
                    fileStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }

At this point buffer contains the point cloud data - I would strongly recommend you ship this off the device via a binary service call, as I think making the poor thing try and convert it to JSON or XML would make things slower than you would like

Verticillaster

Answer 5

Thank you Mark for your advice. I am a novice programmer and it is my first time working with java... I am interested in exporting the Tango acquired PointCloud data to a file and I would like to ask for your feedback on my approach (I created a Save button, and onClick the data would be saved to a file on an external drive). Please find the code bellow for the part that should save the xyzIj data:

@Override
public void onClick(View v) {
    switch (v.getId()) {
    ...
        case R.id.save_button:
            savePointCloud();
            break;
        default:
            Log.w(TAG, "Unrecognized button click.");
        }
}


private static void savePointCloud(final TangoXyzIjData xyzIj, String file) {
    File directoryName =  getAlbumStorageDir(file);
    FileOutputStream out = new FileOutputStream(directoryName,"text.txt");
    byte[] buffer = new byte[xyzIj.xyzCount * 3 * 4];
    FileInputStream fileStream = new FileInputStream(
            xyzIj.xyzParcelFileDescriptor.getFileDescriptor());
    int read;
       while ((read=fileStream.read(buffer))!=1){
           try{
           out.write(buffer, 0, read);
           out.close();
           System.out.println("Printed to file");
       }catch(IOException e){e.printStackTrace();}
       }
}

public File getAlbumStorageDir(String dirName) {
    if (!isExternalStorageWritable()) {
        return null;
    } else {
        // Get the directory for the user's public downloads directory.
        File file = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_DOWNLOADS), dirName);
        if (!file.mkdirs() || !file.exists()) {
            Log.e(TAG, "Directory not created");
            return null;
        }
        return file;
    }
}

public boolean isExternalStorageWritable() {
    String state = Environment.getExternalStorageState();
    if ((Environment.MEDIA_MOUNTED.equals(state)
            && Environment.MEDIA_MOUNTED_READ_ONLY.equals(state))) {
        return true;
    } else {
        Log.e(TAG, "External storage is not mounted READ/WRITE.");
        return false;
    }
}

Foil