how would i go about making this CMOS trackable like this?

I

iFilm7

Active member
http://www.youtube.com/watch?v=IU_reTt7Hj4

this look like it was shot on a CMOS sensor making it DIFFICULT to track especially when there are fast camera movements in here?
how would i go about making something trackable like this?
i have visual effects for directors from hollywood camera work, hopefully thatll help me (:
 
I haven't done much tracking but here's a couple observations:

It depends on what you want tracked. The scene, the person or objects held by the person. So you'de need to isolate the areas of interest by masking out anything else that would interfere with the tracker.

Scene blurring can be a problem depending again on what you want tracked.
If it's just an object in his hand and the camera steadies enough during the region of interest then the blurring before and after can be masked out, the object isolated then tracked.

If that's not possible, note that the scene could be shot at higher speed with a fast shutter which outputs minimal blurring better suited to tracking.
After tracking the composite can be post blurred using a variety of methods to get the final 'motion blurred' result.
That would be a consideration if the camera had to move so quickly that the scene couldn't be tracked using conventional methods. Post blurring these days is pretty easy with various plugins. (RevisionFX ReelSmart MotionBlur seems popular and fairly cheap, for example.)

-Gord.
 
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thanks GORD, your statements are correct, although its only for CCD's
but this video filmed with a CMOS Sensor and it made 'jello'...
 
Sorry. The prinicpals should be the same regardless of CMOS or not.

A rolling shutter however will make it unusable but you didn't mention what camera you used. Some presumptions on my part.

Rolling shutters by nature have each vertical line shifting in the frame when the camera is moving thus making most tracking efforst fruitless without a great deal of effort to correct.
(To my knowledge the Red camera is the least succeptical and most forgiving to tracking problems. Other people have testified the Red is not generally a problem with tracking. That would be an exception to the rule otherwise then.)

If it was given to you already shot then sure it may be unusable or unfixable.
And if it was given to you after the fact and shot with a rolling shutter then your problems are quickly becoming insurmountable.

I'm curious though if not for reasons above why you can't sort it out.
Let me know.

//Barring any of that, can you post or PM me 2 seconds of footage or so and I'll have a look at it to get a better idea.


//ahh. you're still speculating. You don't actually have any footage. :) In that case, no worries, just follow the guidelines and ideally have no rolling shutter cameras for the VFX scenes. :)
-Gord.
 
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I don't touch rolling shutter footage, even from people I'd give anything to work with.
Won't touch it because in the end, it won't track and no one will know why except that the result sucks and I'll get the bad rep for it. So, no way. The Red footage? Sure, worth a look.

If that is indeed your problem with the footage.

//I can't visually tell by watching footage whether it's rolling shutter or not. That's not the point. If the vertical lines are off from start to fininish on each frame the tracking math is going to go berserk. Bottom line.


-Cheers.
 
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Won't touch it because in the end, it won't track and no one will know why except that the result sucks and I'll get the bad rep for it.
Click to expand...

There is always hand tracking/adjustment and I love to work with crappy footage, because you then make your effects match the crap and it looks more like its real and not CG
 
drk3p said:
There is always hand tracking/adjustment and I love to work with crappy footage, because you then make your effects match the crap and it looks more like its real and not CG
Click to expand...


...because you then make your effects match the crap and it looks more like its real and not CG
Click to expand...
Pardon me?

//I think your talking more about post compositing. The tracking itself should be as clean and accurate as possible.
After that, sure, crap up the CG in post to match the poor video.
It just sounded funny when you first said it. But hand tracking is a last restort, not an advantage, to be specific.
 
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you dont know why it wont track? it wont track because cmos footage have rolling shutter and distorts the image. how did they track it nicely in that video i posted even though they used a cmos sensor?
 
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