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Wire Removal On A Difficult Shot...


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#1 hiphopcr

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Posted 31 December 2004 - 04:52 PM

I have a wire that is passing in front of a background with various colors and a couple lights, and the camera is moving. The big problem is that the wire is going kind of sideways (almost 45 degrees) and no matter what methods we've employed it still leaves a trace of something rising with the wire.

We've used errode, blur, and sharpen, masking, wire removal, and cloning... still can't get it looking real.

The shot has about 50 frames.

Any ideas from you experienced fusioners?

Thanks!

#2 isotropy

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Posted 01 January 2005 - 01:13 PM

What we generally do is paint one clean frame, if possible, and track that into place, and do roto on the FG elements to plunk them over top.

#3 hiphopcr

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Posted 01 January 2005 - 09:04 PM

True, and I like that (I need to brush up on my tracking skills for sure), the problem is that the camera is moving quite a bit, going backwards and tilting, and it's not extremely smooth either.

I was thinking about just painting (cloning) the first frame and tracking it, I'll just have to try to match the camera's movements. Thanks for the advice!

#4 shaily

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Posted 04 January 2005 - 09:19 AM

hi,
try to manage the shot in parts ,as you said the wire has angle ,use smaller polylines & if needful set them to paint limited frames ,try to patch parts instead of the whole frame, that shall ease you at tracking.

shaily.

#5 Michael Wolf

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Posted 05 January 2005 - 03:54 AM

You could try to stabilize the footage onto a larger canvas (i.e. twice the size of the original footage) and go from there. This will (if your shot allows) basically result in a canvas with a fixed shot contents, and a moving/sliding window representing the camera movement.
You will need some expression trickery though to stabilize/de-stabilize on a canvas larger than the original footage.

Cheers,
Mike

#6 Sebastian Witkin

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Posted 05 January 2005 - 07:54 AM

How about using the difference keyer to pull out the wires? Has been a life saver for me in the past. Though with out seeing your footage I cant be sure that it would be applicable, still I thought I ought to suggest it! Good Luck

#7 hiphopcr

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Posted 05 January 2005 - 02:17 PM

Really nice tips guys, actually I'm watching this scene over and over and the background is highly animated. Behind the curtains there are doors opening and people running around (partially transparent due to the curtains), plus the camera is moving like crazy. The track on it looks like a roller coaster.

I had fairly decent success just cleaning up one frame and tracking it over the background, but the background has so many moving parts I can't leave it as a still image.

So I'm gonna try the difference key or some crazy clone tracking cuz regular techniques and tracking just aren't gonna do it.

You guys are all so smart thanks again!

#8 skonrad

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Posted 05 January 2005 - 04:11 PM

I had a nigh impossible paint shot a while ago of a big set of wires moving in front of an actor's shirt while he was bouncing up and down and just generally being a difficult actor. What I ended up doing was painting a clean frame every five or ten frames either by using a clone tool or by grabbing a near frame where the wire didn't pass in front of the object, and then using the krokodove morph plugin to morph between these frames. I then tracked the problematic areas back in frame by frame.

The final result was a mess of about twenty flows that I constantly had to go back and edit (flow groups would be a great DF 5 feature - anyone agree?) and remorph depending on whether or not I did a good job the first time around.

I have no idea if this would work in your shot. Just throwing the thought out there.

#9 hiphopcr

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Posted 05 January 2005 - 06:13 PM

Skon,

that's a very interesting possibility, and I happen to have that krokodove morph plugin. I get what you're saying and I have to say you must be crazy to have thought up something like that but thanks, cuz I was starting to get that crazy too.

Thanks!

#10 skonrad

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Posted 06 January 2005 - 08:34 PM

I actually knew from the beginning that I was going to have to do it that way, as my mind was just fresh from redoing a bunch of (intentionally near impossible in house created) morphing tutorials a week or so before I started hacking away at it. Crazy didn't really factor in. My scripts, however, almost without exception, implement great deals of the crazy factor.

Under different circumstances I might've just gone ahead and gone through the pain of just painting it out very slowly, but I was working in 4k, and as the board has established earlier, the paint tool flakes out at high resolutions when you have too many strokes.

Some of the more complex wire removal shots we've done (in particular, huge chunks of one shot having been done by isotropy above over the period of two months along with most of the department helping out) involved basically hand tracking painted features frame by frame. So, an eye, a hair part area, a collar - separated from a gradianted / oddly lit background for a shot that included the other problem of the camera moving around a table. And then, someone apparently also applied the morphing technique.

At the time we were trying out Mokey, a tool heralded for its ability to do wire removal shots in the fraction of the time traditional rig removal techniques take, which couldn't handle it at all, even on the most simple part - the gradiented background. Even when the demo version forced me to render an 8 bit sequence that clamped my colours and didn't give me any control over how my cineons were used, it still looked worse than everything we'd done thus far. The unfortunate thing is that sometimes rig removal requires huge amounts of time and great deals of finesse, especially for film work where every wrinkle of a fabric becomes a potential nightmare. Sometimes even the best tricks don't work and it becomes a painful and arduous. Therein lies the beauty of DF - it let's you do everything, even if you sometimes have to find ways around these fissures. The only real trick I have developed is just to find some zen in the process and then brag to my peers once the whole shebang is done with.

And beer.




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