Motion Blur Edges for Green Screen Comps

A cool technique for getting natural motion blur edges on green screen comps. Actually not just green screen, anything where you need to re-add motion blur to soften off a comp. For example if you have roto’d a finger over a screen comp this is useful. I pull this setup out of my user bin all the time.

This was featured in the Siggraph presentation I just did, and a few people were interested in it, so here it is with the setup:

The batch setup:

The same as an archive

Let me know if it’s useful for you

Cheers

Rufus

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Thanks so much for posting this. Great presentation too!

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Beautiful work and thanks for this supplemental bite out from the whole.

I misremembered the part about the motion blur in the original footage so I wonder if 90 degree shutter speed at the acquisition stage would help with keying? As with dual ISO I wonder if sensor manufacturers might introduce dual-shutter, and you could then eat have more freedom in mixing and matching and cutting if you had access to them both?

Cheers
Tony

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Thanks so much for posting this. When you mention you’ve done some Wash on the motion blurred edges at 1:50, where did that Wash come from? Did you just sample the color of her dress and Paint it a frame at a time? Thanks!

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Thanks much for sharing the setup. Your presentation was great today. A lot was packed into that hour. Some really cool techniques.

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very cool technique, thanks Rufus…can’t wait til the whole presentation is available to view.

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Yup thats basically exactly it. I think sampling a brighter, highish saturation area worked best on this one. Then use the wash option in the paint mode menu.It’s something we used to do more often, and somewhat considered a dirty fix, but in this case with transparent red on green, to two being opposing colours, it did help.

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Thanks @RufusBlackwell for the tips. I love a bit of wash. If it helps anybody, another way to get this to wash without paint is to use @miles y sample and use the chroma (UV) of that with Y of front in a matted area.

Again for posterity only: for transparent edges I always like to recall this tutorial which can get some nice edges too.

Credit to Dumbledorf for this.

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I love this technique :point_up:

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stumbled upon this today and had a play with it but it does not seem to work with some blue screen material that i have. also i’m working in ACES so maybe the math is wrong as Dumbledorf’s footage looks like rec. Anyone get this to work? @johnt

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I have used this in the past and i think I have done it correctly.

flame 2020.3.1 - Dropbox - blueScreen.zip - Simplify your life

Sorry for the delay @TimC

Convert to aces cct ie log for any stuff like this or grading using input transform then invert to get back. I’m always jumping in and out of log.