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Old May 28th, 2009, 06:01 PM   #1
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How does it work.

You may have seen it in motor sports where a comparrison between two cars is beeing overlayed on the track at the same place at the same time, even if the cars were driving the track one at a time.

The camera is moving, following the action. Dosn't look anything like motion control camera rig, so what is the technology making this possible called?

The early version of this, I emagine was seen on American football, where you could see a graphical overlay of the yardlines in real time, while the camera follows the action. Sortof what you could expect boujou to do, only this happens in real time.

Now the technology has advanced beyound my understanding.

Car 1 runs the track alone. Then Car 2 runs the same track later. Both cars are being followed by 10 or more cameras manually. Then after the race magic happens. The rerun shows you both cars on the track driving, side by side or sometime overlapping eachother. In the same shot! By all cameras! Ecaxtly how they were followed individually. How is that possible?
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Old June 20th, 2009, 02:07 PM   #2
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It's chroma key. Real easy for the football lines. More work with the race cars, I'm sure.
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Old June 21st, 2009, 01:21 AM   #3
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My assumption would be that the truck following the race feeds all the cameras to either tape or more likely today, digital storage. So in post, they have access to all the iso shots each will also contain timecode.

Then it's pretty simple to composite the same shots from each run into a single display starting at a particular point in time and running the two real time tapes against each other and demonstrating how the two cars traveled the same route over the same period of time.

It's not a chroma key, which as you note, requires a particular colored background.

I'd suspect that they're using something like a "non-additive dissolve" or other mathematical composite mode to combine the two shots into a single scene.

Just my best guess.
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Old June 21st, 2009, 06:35 AM   #4
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Thanks Bill for the answer, but I don't think you hit it either.

The key function I am looking for is the one that enables a seemingly NON motion controlled camera to enable the replay very quickly.

Let me ask my question differently if I didn't manage to explain it clear enough first time.

You shoot a scene with a handheld camera. In that scene you follow the movement of a red ball rolling down a hill. In take two you follow the movement of a blue ball rolling down the same hill. Approx four minutes later you are able to combine those two takes into one shot, showing both balls rolling down. Not in split screen. In the SAME shot.

This would require some heavy processing to figure out how the hills geometry is being shot, so that it can overlay the image.

Im sure there is much more to it, than just a camera shooting the sceene.

Perhaps the balls have a GPS build in, and the hill is being graphically generated, so that what you see in the replay is in fact CGI I don't know. But whenever I see it being shown in sports it looks like liveaction.
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Old June 21st, 2009, 08:19 PM   #5
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Nik,

I think you're overthinking this.

You roll the red ball. You follow it with a camera on a decent tripod which means the geometry of the shot is from a fixed position AND at a reasonably FIXED rate of speed determined by the camera op keeping the ball at or near the center of the frame. The ball takes 10 seconds to go from the top to the bottom.
SHOT 1 IS DONE.

Next you roll the blue ball. It's followed in the same fashion with the same camera from the same position. The speed will be constant since it's governed by the affect of gravity on the BLUE ball - exactly like it was on the RED ball.
SHOT 2 is DONE.

You slap both shots on the timeline of any NLE stacking them on adjacent tracks.

On the BLUE ball track you crop,, set a BLUE color traveling matte, or just set both tracks with transparency to taste - or use the non-additive dissolve I mentioned - and THAT'S IT.

Tweeking the parameters you can now watch BOTH balls on the same shot in real time - likely without rendering since it's just a simple 2 shot composite.

This is NOT particularly difficult - unless you want a specific look that you can't achieve with these simple techniques. But the fundamental principals are NOT difficult nor particularly computationally taxing.

FWIW.
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Old June 22nd, 2009, 01:21 AM   #6
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Actually, if what you are asking what I think you are asking, then it is, in fact, quite complex, and requires some very high-end horsepower (pun intended) to pull off the synchronicity in the shots.

I don't remember if I read a document or if I saw a program on this a year or two ago, but what I saw encompassed a number of technologies to pull this kind of stuff off in near-real time for some types of live racing broadcasts - such as when you see cars in live broadcast and you see overlays following the cars with text box info in them. The overlays attach to each car and follow them as they move on the track - and much of it is done live.

Some of it involves location sensing on the body of each car, tuned to receptors placed around the track. The information streaming from this system is synced to video recording equipment that not only records multiple feeds, but syncs it with the incoming location sensors, and has the ability to dynamically reference extraneous data that a controller or broadcast producer inputs for each individual location identifier - which to the viewer corresponds to each individual car on the track - documenting each car, their location, and at which point that were at said location. Each of these cameras are streamed into massive data storage and retained in their individual streams with syncing info intact. Some of them may be fixed remote motion controlled cameras, others may be roving such as pace-truck cams, etc. All of them are synced to the central data unit. (Yes, we're talking about massive amounts of investment here, but some professional motor sports are among the most well funded endeavors in pro sports......lots and lots of money.)

Such a system allows for near-live broadcast playback, but also presents a few options for instant replay with a choice of parameters, including determination of position of all cars at any given point in time, or performance review of each individual car when they were located at a certain spot on the track (either in the same race or spanned across multiple races). With fast enough processing and data handling, along with a crack production team, they can manage multiple combinations of feed syncs between stored data overlays on live footage. It is quite impressive.

I wish I knew more about it, such as what type of gear they are using (brands, models and other hardware) but it has been a while and I didn't retain much of the info.

-Jon
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Old June 22nd, 2009, 08:20 AM   #7
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Thanks Jon I think you hit it right on the spot. Any idea what this tech might be called?

I don't expect to have the funds to purchase or even rent such a system. But it amazes me, and I would like to read more about it, how they pulled it off. However in order for being able to google anything, you need the right "keyword"

Now that you mention the overlays of text following the cars, I remember nascar using exactly that.
Formula 1 showed some replays of qualifying rounds, where two individual racers were superimposed on the track in real time, showing exactly how their driving lines were in comparrison. Avesome.
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Old June 22nd, 2009, 10:33 AM   #8
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I have done camera work onauto racing and while I didn't work the video truck and can't tell you exactly how what you're asking is done, I can tell you that typically NASCAR at least runs somewhere in the area of 10 robotic (some static for speed shots, flag stand, race control and pit out-and 4 to 5 pan/tilt head cameras-4 corners plus front and back stretch) plus the broadcast company be it Speed, TNT, ESPN or any of the majors) there can be as many as 6 or 7 hardmounted cameras (think studio type) usually 2 or 3 on the roof of the booth, plus corners THEN there are the handheld for the pit reporters, plus of course a couple for the race broadcasters. Point is there are a whole lot of cameras, miles of cable,fiber optic and a crew of about 185 up to 225. The video truck is a crowed as can be. The producer, director, ADs, graphics people, spotters with so many monitors and noise it's really unbelieveable.The equipment is as up to date as one could imagine and the kind of graphics and imagrey you are talking about is done fast, precisely and in realtime and frankly is not the kind of thing you and I could do with teh gear we have, at least not in the same way.
Jonathan hit the nail on the head. It really is quite something to watch (while watching the 6 other monitors that are set up in front of you. I never really watched the on air monitor as I had to concentrate on the monitor that was set to my camera and the monitor of the camera in the turn before and the hard camera monitor of the turn before. Plus of course the monitors of the other robocams just for fun and then the director in my ear. Lots going on.
Point is, agaon, could you or I do it? Sure.In real time? Nope. It's a complicated process that requires lots of gear and manpower to accomplish in real time.
But it sure is fun!
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Old June 22nd, 2009, 11:22 AM   #9
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Quote:
Originally Posted by Nik Skjoth View Post
Any idea what this tech might be called?
.
I really have no idea. I do know that it spans multiple technologies brought together by numerous partnerships with innovators in their various fields. You can probably type in keywords like "enhanced broadcast" with NASCAR to get you started, but you'll probably have to do a lot of digging. I am pretty sure I may have seen some of what I saw on a Discovery Channel program or something like that, and I think some stuff I read in an article from Wired Magazine that I no longer have, but I just don't remember. I actually don't even follow the sport at all.

And I didn't even touch on any of the constant developments with interactive technologies for in-car data or with the drivers themselves. Amazing stuff - but I have no idea what kind of stuff they are using, other than that it involves a wide range of technology provider partnerships to make it all work. (Resulting in corporate logos being plastered over every possible inch of attachable surface on the cars, helmets, driver uniforms, and facility flat spaces.)

-Jon
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Old June 22nd, 2009, 02:11 PM   #10
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Cameras used by the NFL to overly gfx on screen (like the firs down marker) are mounted on special tripods that send tilt and plan info back to a computer and the camera itself is rigged to send back zoom info. So that's why the first down marker doesn't move up/down the field as the human controlled camera follows the action. I assume a similar setup is used by NASCAR.

Also, and this is complete speculation on my part, they might be using some sort of 'car recognition' technology to help rotoscope a race car so it can be composited into a shot w/another car. I mean, if consumer cameras can 'recognize' human faces (which vary widely) professional software should be able to recognize stock cars which all look very similar, right?


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Old June 22nd, 2009, 02:45 PM   #11
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Originally Posted by Andrew Kimery View Post
Cameras used by the NFL to overly gfx on screen (like the firs down marker) are mounted on special tripods that send tilt and plan info back to a computer and the camera itself is rigged to send back zoom info. So that's why the first down marker doesn't move up/down the field as the human controlled camera follows the action. I assume a similar setup is used by NASCAR.

Also, and this is complete speculation on my part, they might be using some sort of 'car recognition' technology to help rotoscope a race car so it can be composited into a shot w/another car. I mean, if consumer cameras can 'recognize' human faces (which vary widely) professional software should be able to recognize stock cars which all look very similar, right?


-A
I've never seen anything like that on a NASCAR track-the only thing is the robotic cams and the movement of the camera is handled by an operator in a seperate truck or building if you get lucky. BTW, the robcam operators can be as much as 1/4 mile or farther from some of the cameras. All fiber cable to the box from the tripod head. Like I said all the others are either for handheld use (think typical broadcast type cameras) and hardmounted (think studio type) but I like your idea. I bet the ADs and grahpics folks would like it too.
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Old June 22nd, 2009, 03:12 PM   #12
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Apparently the company responsible for this cool stuff (both in the NFL, NASCAR, as well as the glowing hockey puck FOX used to have) is called Sportvision and RACERf/x is the name product/system they use w/racing.


-A
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Old June 22nd, 2009, 07:27 PM   #13
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Thanks for the great insight Don. It sure sounds complicated as I assumed it would be. If anyone ever stumbles uppon any kind of "behind the scenes" web documentary about this stuff, please give a shout.

I would estimate that some time in the future, this tech will be adopted in feature film production aswell. To minimize post VFX preperation.

Wouldn't it be cool if all your raw footage already had motion tracking info in the metadata.
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Old June 23rd, 2009, 12:43 AM   #14
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Ahhhhh.... NOW I understand what you're asking. You want to know about the "1st & 10" system used in football games and adapted to NASCAR.

I got a tour with the Arizona Cardinal's stadium production staff prior to the Super Bowl a couple of year ago and asked just that question.

They sent me a link to the "how stuff works" web site that explains it in more detail.

Here's a URL to get started.... HowStuffWorks "How RACEf/x Works"

Enjoy.
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Old June 23rd, 2009, 01:40 PM   #15
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"Sportvision", "Race F/X" and specifically "simulcam" thats it. Thanks a bunch.. avsome

Last edited by Nik Skjoth; June 23rd, 2009 at 02:24 PM.
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