Gewalter Benjamin

I am using jit.gl.gridshape to be able to place a chroma keyed image in a scene I broadcasting to youtube live from jitter. The problem is that I am getting a thing black frame on the edge of the gridshape, that I can't figure out how to eliminate... I am sure there is a simple solution but I've searched around the forum but can't find anything (it seems that the search function has lost quite a lot a bit of accuracy... I am turning up lots of results about Max4Live that seemingly don't even integrate jitter).

I've created a simplified ready-to-view patch that shows the problem I am dealing with. Any help is hugely appreciated.

I am using jit.gl.gridshape to be able to place a chroma keyed image in a scene I broadcasting to youtube live from jitter. The problem is t

eliminate-black-frame-around-gridshape-plane

i would put a tr.edgeblend.jxs slab directly after the chromakey

Hi Rob, thank you so much for getting back to me. My resulting patch is posted and I've done my best to make it quick an intuitive to follow the problem (all jitter included movies, ready to go when opening)

I tried tr.edgeblend.jxs after each chromakey individually, as well as after the multiplication of each mask (as shown here... I am using the chromakey in mask mode i.e. mode 1, in order to key out multiple colors), but there is a problem in that I am trying to eliminate the colored edge that remains after chromakeying the video in the gridshape (the gridshape seems to be the problem, not the keying). As the gridshape becomes a texture via jit.gl.node (I am doing it this way because I am using jit.gl.gridshape to position my video in various areas of the scene and at different scales), when tr.edgeblend.jxs is applied, it is applied to the entire texture. Therefore, the edgeblend's gradient does not provide the accuracy needed to eliminate this frame that the gridshape is causing.

In the chromakey subpatch, there is an on/off switch to illustrate this issue. (switch sending from main patcher as well)

I want to ask the question: what is the root of this problem? My first thoughts are that it is resulting artefact from applying @color 1. 1. 1. 1. to the gridshape... it seems that a slight white line is remaining, but I don't know how to maintain full color video if I eliminate this attribute. It could be an unreasonable suspicion though.

I tried tr.edgeblend.jxs after each chromakey individually, as well as after the multiplication of each mask (as shown here... I am using the chromakey in mask mode i.e. mode 1, in order to  key out multiple colors), but there is a problem in that I am trying to eliminate the colored edge that remains after chromakeying the video in the gridshape (the gridshape seems to be the problem, not the keying). As the gridshape becomes a texture via jit.gl.node (I am doing it this way because I am using jit.gl.gridshape to position my video in various areas of the scene and at different scales), when tr.edgeblend.jxs is applied, it is applied to the entire texture. Therefore, the edgeblend's gradient does not provide the accuracy needed to eliminate this frame that the gridshape is causing.

i would recommend restructuring your signal path a bit.

in my experience, the path should go something like:

video source --> chromakey / matte creation --> edgeblend (each of these operations performed on a fullscreen quad) --> compositing / mapping on geometry

in my experience, the path should go something like:
video source --> chromakey / matte creation --> edgeblend (each of these operations performed on a fullscreen quad) --> compositing / mapping on geometry

Hey Rob, thanks, your advice made me realize the fundamental flaw in my logic -- why was I using gridshape to reposition and rescale the video I need to key? So now I am moving from jit.movie --> tr.edgeblend.jxs --> td.rota.jxs @boundmode 1 --> chromakey and it works perfectly and seems much less expensive. Cheers.

Eliminate edge/frame around gridshape plane after chromakey?