How does BackgroundSubtraction work?

So I’d like to perform some background subtraction, and turns out there’s already a (addon) node for this - however, it doesn’t have a helppatch, and no matter what I put at the inputs, it only seems to pass the texture at “Input” directly through - how do I make it work?


Inside BackgroundSubtraction (EX9.Effect) is a Blend (EX9.RenderState Advanced) node.

Try setting Alpha Blending to 1.

No dice.

If it matters, my patch is as follows:

Hi tml,

haven’t tried it with VideoIn, but i faked a green screen and got the teapot back.

Not really sure about the Blend Node inside BackgroundSubtraction, but seems to work if removed or with Alpha Blending = 1.

The result is not spectacular compared to compositing plugins, but seems to do what it says.

BackgroundSubtraction_demo.v4p (21.2 kB)

Huh, your patch works. Interesting, will look into, thanks!