i would recommend you do this a bit differently, using shared contexts. you can render and draw the scene once, capture it to texture, and share that texture with the shared-context. that way you'll have the exact same scene in both contexts, and only have to render it once.

you can create the smearing effect with the captured texture, by setting the gl.node @erase_color to 0 0 0 0, and using jit.gl.pix to create the effect.

patch below:

Rob, you rock ! I would never have found this solution. + It might be the occasion for me to get into gen things. Actually, it's a problem I had in another patch/project, but never found the time to make a simple patch to demonstrate. One stone two birds :)

Thanks a lot, I owe you one !

Yoann

ps: here is a early test of this slitscan patch: https://vimeo.com/61000279