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Computer Graphics? Or Real? "Ultimate Batting Practice" (video) (youtube.com)
3 points by ColinWright on Aug 12, 2011 | hide | past | favorite | 4 comments



I wouldn't normally submit something like this. It's not "deeply interesting" and it's not technical, but I was watching it and thinking - computer graphics?

But I can't see how it can be fake, unless the ability of the software these days is significantly beyond what I thought. So I figured I'd ask the community I have contact with that's likely to know the most about it.

And that's HN.

So I ask: Is it for real?


Film guy here. It wouldn't be that hard to fake. angle of the sun/direction of shadow is easy to keep consistent, motion blur is wholly automated these days (as in, select start/end frame & position, and motion blur will be on by default in most programs with excellent results). Although the camera is moving slightly, the distinctive and structured shapes of the batting nets provide perfect tracking points for trajectory mapping; alternatively, you could shoot at a higher resolution from a tripod and then introduce some floaty movement afterwards, windowing onto a smaller frame at 1:1 resolution. Making the nets bounce is trivial, you just need a couple of takes from the same camera position. As long as the light isn't changing, it's astonishingly easy to key stuff in and out from different frames - typically used to remove people or vehicles, but just as easy to introduce them. So it's possible that this is a film school/enthusiast project; I'd say it could be done in a single day on an average workstation.

On the other hand, the guy may just be a good batter. Bouncing a ball off 4 nets will rob it of a lot of speed, and if one practices a lot it's not that hard to get a rhythm going. When I was a teenager I used to kick a soccer ball off a wall for practice, and my aim was kick it back 100 times, starting over from 0 if I lost it. I wasn't all especially good or dedicated, so I have no problem believing this would be achievable by someone who's serious about the sport. Jugglers have to perform far more complex movements at much faster speeds, for that matter. Finally, for all we know this could have been the 10th or greater attempt to pull this off.

So either is possible. I don't feel like downloading the video and stabilizing it to do a windowed frame diff, but if you wanted to get forensic on its ass the best place to start would be to measure the # of frames between hits, because you're got a nice marker from the noise of the bat; if it's exactly the same more than 3 times in a row suspect a fake, likewise if you see a repeating progression of frame intervals like 23-25-24-23-25-24.


Pretty sure it's fake - plenty of faked sports videos. Look for the video with Ronaldinho hitting the crossbar three times with a soccer ball. Insanity, but fake.

Still awesome though.


Follow-up: http://news.ycombinator.com/item?id=2878992

Conclusion: it's a fake.




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