Custom Armature

PapaJetEngine

Hey! Thanks so much for all the effort you guys are putting in, this is an amazing effort. I found about it while looking for DIY mocap solutions, so I dove in and am building a suit with Rev2.2 boards (silly me didn't know there was a new version).

My plan is to use the suit to create animations for Unreal, on the Unreal skeleton. I understand how notochord on the pi is able to specify bone names through the xml file (i've been separately dealing with soldering jobs that seem to have burnt up the imus), but I keep seeing the Armature field in the blender add-on empty. Is there a way for me to map my k_ceptors directly onto the unreal skeleton instead of the default so I don't have to retarget later? I'm cool with rolling my own python if need be, just looking for a place to start.

Also, please forgive me if this is written somewhere else, I've been poking around for it on the wiki and in the forum for awhile but haven't been able to understand it 100% yet.

daylanKifky

Hi @PapaJetEngine, welcome to the forum!
Good to know you are building your own rig. The R2.2 works fine, the 2.3 has only a few additions, but in essence they are pretty similar.

PapaJetEngine but I keep seeing the Armature field in the blender add-on empty.

Are you referring to the field in the Armature node?

That field should be used to select the working armature in blender. You can use any armature you like there. What the node will do is to assign any incoming message with datatarget Q (Quaternion rotation) to the bone with the same name.
So if yo change the nameof the bones of your armature to match those of the default chordata avatar you should be able to directly control it.

You can use the Dump node to inspect the messages coming from the notochord.

This is a simplification of the process, things can get more complicated it the armature you want to use differs in bonecount, or bone distribution from chordata's default biped one. If that's the case give me more details and we will try to guide you. In that context @Dodo2207's script might come handy (by the way, you can find it here)

Dodo2207

Hi @PapaJetEngine, I wrote a simple retarget script. You can find in the forum. You need to import your Unreal armature in Blender, change the parameters in the script and run it.
Its simple to understand and has many comments on it. If you have trouble with it just say it 👍

PapaJetEngine

Awesome, I'll check it out and give it a go sometime this week, thanks!!

PapaJetEngine

Sorry that it's taken me a couple weeks to get back to this. My bad on being vague, I meant the Armature Config field on the Notochord Node:

I'm just getting my newest kceptors plugged in after the set that I thought was fine suddenly started spinning after sitting awhile. I re-calibrated but that didn't do the trick but maybe I did it wrong with electronics in the wrong spot. Trying again this evening, then I'll take a look at the python script. The new armature will have more bones, specifically in the back and I may add the shoulder (clavicle actually I guess) k captors if my old ones re-calibrate correctly.

daylanKifky

Hi!
That field in the notochord node is not used for now. In the future it will allow you to create and modify the configuration XML file that notochord reads upon startup, but for now you have to modify it in the raspberry.
Setting it or leavning it blank in blender has no effect.

PapaJetEngine I did it wrong with electronics in the wrong spot.

If you get to run the notochord with in --scan mode with one of your KCeptors attached and it gets read then the electronic part should be fine working, and you should start gettting some messages in Blender. If you don't there's probably a firewall blocking them.

PapaJetEngine

Ok, good to know that leaving it blank is the move for now. Apologies for the unclear language, I meant I may have calibrated with a laptop too close to the k_ceptors. I have the communication with the raspberry pi and my mac and blender working fine. Turns out the issue with mapping the bones directly to the bone names of the unreal skeleton was that the unreal skeleton had multiple root bone structures which I noticed is unsupported when I looked at the python code where it was erring. My attempts to re-code that bit of python failed so I'm going with a modified unreal skeleton and then I'll use @Dodo2207 's retargeting script to get the data from my modified one to the engine-supported version (or I'll try a different retargeting scheme in Unreal, but that all is outside the scope of chordata, so I won't go into too much more detail here).

I'll go ahead and say this is solved thanks to the retargeting script, thanks guys!