Vl.OpenCV EstimatePose Crashes

I have some trouble reproducing the vvvvTV OpenCV example. (See here: https://www.youtube.com/watch?v=4hPH5CokxwQ&feature=youtu.be)

The EstimatePose node crashes everything, whenever I connect it to the MarkerDetector. The current EstimatePose node also misses the TransformationMatrix Output it has in the tutorial? Do you guys have any idea how to prevent the crashes and extract the transformation matrix.

I’m currently patching this in VL as a Node in Beta40.

Thanks a lot for your help!

Hi @maxs, which versions of beta and VL.OpenCV are you using?

Hey @ravazquez thanks for your answer!
I’m using the latest stable beta 40 release and VL.OpenCV 1.1.4

@maxs I have to double check this but try things out with the version of VL.OpenCV stated here: https://vvvv.org/blog/vvvv50beta39.1

I believe this is the last known version to work with beta (again I need to double check).

Thanks a lot @ravazquez ! I’ll try it out.
And is there an easy way to get the Transformation Matrix from the EstimatePose Node even if that pin is missing now?

@maxs I am not sure what you are trying to do but:

  • There is strong progress currently ongoing to get this to work in gamma, a release may happen as early as next week. So if gamma is an option for you, I would recommend waiting for that.
  • If beta is your thing, then instead of trying to reaplicate the rather dated VL.OpenCV youtube episode I’d suggest looking into the library’s girlpower folder, it contains a working Aruco demo. You should be able to find it at <VL.OpenCV dir>\vvvv\girlpower\ArucoEstimatePoseDemo.v4p

Thank you for this straight forward explanation. The help patch made some things really clear! Though I’m a bit stuck still because the UploadImage Node does not seem to work in Beta39 or Beta39.1, while it works in Beta40, but the EstimatePose node crashes everything there. Is this maybe depending on the OpenCV version I use?

I would really like to do it in gamma and I’m really looking forward to the upcoming update, but for this one I’m in the need of some field trip nodes, which are still missing in gamma, so beta seems the only way at the moment.

could you please give it a spin if it works for you with the latest beta41 preview and latest vl.opencv?

Hey @joreg, thanks for the hint. I tried it and UploadImage works in the latest preview, but EstimatePose crashes everything here as well, as soon as I show an ArucoMarker to the Camera.

hello again @maxs,

I just pushed updates on this to github. I don’t know how familiar you are with development in general but if you feel like trying it out here is what you need to do to get the latest (non-yet official) changes:

  1. Using git, clone https://github.com/vvvv/VL.OpenCV.git
  2. Once cloned, checkout the Stride branch of the repo (git checkout Stride or use a git client)
  3. Using Visual Studio 2019, open [path to your cloned repo]\src\VL.OpenCV.sln
  4. Build the solution in Visual Studio
  5. Make sure you have an args.txt file in C:\vvvv\vvvv_beta_41-0007_preview_x64 (or your version of beta)
  6. Make sure your args.txt file contains a line like: /package-repositories C:\[path to folder containing your cloned repo]
  7. You are done, open beta and check out the help patches!

This was tested againt beta 41-7

If that is too complex, you will need to wait for this to be tested some more and pushed as a new nuget. I’d say that will be in about a week’s time.


Hey @ravazquez thanks a lot for your effort and your in depth explanation!
This sounds like I could get this going, so I’ll give it a try.

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