We are a high school broadcasting team looking to up our productions for all of our shows. We are looking to specifically improve our american football productions, as those are some of our big shows. One common element in an American football game is the yellow first down marker. As you can imagine, this is an extremely difficult thing to accomplish for two main reasons:

  1. Keeping the line in the same place as the camera moves is difficult to achieve.

  2. Getting the line to go under the players and not on top of them is difficult.

We have figured out how to place the line under the players using chroma keying on our switcher, so no problem there. There problem is keeping the line in place. We are looking into motion tracking to achieve this, and stumbled upon something called OpenCV. It is essentially an open source video tracking/interpretation software. It has enough power and acceleration to run in real time.

We are looking to do something like this:

  1. Take live video feed from a Decklink card into Blender
  2. Place a 3D model of the football field over it, and use OpenCV to track it to the field.
  3. In the 3D model layer, or with a layer parented to it, have our graphics play.
  4. Send ONLY these graphics back out to our switcher for use in broadcast.

Everything having an SDK (The video card) or being open source (Blender, OpenCV), does this sound like something that could happen? What issues could arise with it?

Thank you

  • $\begingroup$ afaik Blender doesn't handle live footage... $\endgroup$
    – Samoth
    Commented Jul 7, 2016 at 11:02
  • $\begingroup$ I am looking to incorporate this as the intake from the grabber card, does this sound like something that can be done? $\endgroup$ Commented Jul 7, 2016 at 20:30
  • $\begingroup$ i've been looking for the same thing for some time, the only plosable way to do it is to duplicate a window with clean UI have teh background set to green and mirror that window to OBS so you can source it out as a video output. $\endgroup$ Commented Sep 2, 2019 at 10:33
  • $\begingroup$ This question was one I asked very early on. This paper details how we ended up completing the project. $\endgroup$ Commented Sep 3, 2019 at 11:25
  • $\begingroup$ drive.google.com/open?id=1deBHSbWQEG0gIO_ZPd8jKtOnZp0k2a_F $\endgroup$ Commented Sep 3, 2019 at 11:25

1 Answer 1


This paper details the solutions and challenges, as well as some technical information to how we completed the project.



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