OSC Communication: Can I send it via python straight to port 6565?

DigitalStages

I would like to receive the Quaternion data of each sensor as osc messages via port 6565 in order to use it in openFrameworks on my client machine.

Is there momentarily a way to do that, and how?

Cheers

DigitalStages

I see, there is another discussion already going:
https://forum.chordata.cc/d/124-output-raw-sensor-data-to-pi/15

Still, I am looking for a way to go around Blender by using a python script, that sends quaternion rotation as osc stream to port 6565 from my pi over to my client machine.

duncan006

Hi,

I was the original poster in the thread that you linked. My data was being directly received on the pi, but the same scripts and methodology should work on any client machine. The quaternion data is already what is being sent over port 6565, you just need a listener -that's not blender - that's paying attention. If the client you are using supports python or python integration, you can probably use one of my old bare bones scripts here and only have to customize two functions (handling data and piping data to your program). If not, you might be better off doing it in whatever language is native to your client as it would likely be easier than working around.

If you need a more involved script (for instance, sorting the data into a more readable format) you can see how I did that here. However, that particular script is configured to re-send socket data and outputs euler angles and raw values instead of quaternions.

Hope this was helpful.

DigitalStages

daylanKifky Thanks for your reply. Yes, I hope we get a straight osc feed to be able to dock directly without Blender as "Bridger" soon. Thumbs up :-)

duncan006
I just got barebonesosc.py running on my pi, and it spits out quaternions. I had to run pip3 install python-osc in order to get it work. I think I need to work out a way now, how to get the same thing working on my client machine (as you mentioned in your reply above).

Just running the barebonesosc.py with the wifi network IP does not work. The IP of my pi ends with .53, while my client ends with .170. "localhost" and "...170" stays blank, while "...53" spits out an error. Sorry, I am newbie on that matter.

I ll keep you updated. Nice, that I have the format now, so I can actually work on the code in openFrameworks, even it does not quite work yet: /Chordata/q/kc-CH_2-2: (x,y,z,w)

Cheers

DigitalStages

@duncan006
Many thanks for your links, it is very helpful to start debugging. Through this, I recognized, that no data reach my client machine at all. So the problem does not seem the app I am working on, but the osc data stream.

Therefore a silly question: Is ./bin/notochord --scan the command to start streaming via osc?
And if yes, why could it be that I do not receive data, even though I opened port 6565 to all firewalls?
Or, do I need to run bareboneosc.py or quaternionDump.py on my notochord pi (not like I tried on my client machine) in order to get an osc stream going?

Cheers

daylanKifky

DigitalStages Therefore a silly question: Is ./bin/notochord --scan the command to start streaming via osc?

DigitalStages And if yes, why could it be that I do not receive data, even though I opened port 6565 to all firewalls?

yes it is. Upon startup the notochord will show you a banner with the main settings, check that the transmit output is associated with osc and the ip address is set to your PC.

Just a detail: Keep in mind that the pose calibration routine is currenlty only implemented inside the blender add-on. So if you want to bypass Blender you will need to implement it yourself in OFX. Even if it seems scary because of all the Quaternion math it's not that hard. If you want to give it a try I can help you out.

Otherwise the way to go for now is using the forward node at the end of the chain to get the calibrated data.

We are aware is cumbersome to have Blender running if you are not using it, part of the planned future development is targeted at having the complete data coming out directly from the RPi

DigitalStages

daylanKifky
Ok, good to know, as ofQuaternion is using w at the end in openFrameworks.
ofQuaternion(...)
ofQuaternion::ofQuaternion(float x, float y, float z, float w)

About the new version: I ll keep it in mind, as bundles are better in dealing with the data load. Looking forward to it.

daylanKifky

DigitalStages Nice, that I have the format now, so I can actually work on the code in openFrameworks, even it does not quite work yet: /Chordata/q/kc-CH_2-2: (x,y,z,w)

The quaternion is sent with the W component first so the format of the message is

/Chordata/q/kc-CH_2-2: (w,x,y,z)

NOTE: the new version of the notochord sends the OSC messages inside bundles and uses a replacement technique to avoid repeating the base address. You will notice that the bundle starts with a Nil message containing just the base address like:
/%%/Chordata/q

and then the payload messages with the replacement placeholder
/%/kc-CH_2-2

You can use the plain message format by passing the flag --no_bundles to the notochord

duncan006

DigitalStages The ip address in the script should be the ip address of the host machine, which is also whatever ip you run the notochord with. Otherwise, you'll get an error that's essentially "the address is not valid."

daylanKifky Thank you for mentioning the --no_bundles flag, that cuts a whole handler out of my code!