HVX200 3D Tracking test...

Jim Arthurs said:
now I'm thinking about minature sets with CGI characters... if it ever gets going again, that is.
Click to expand...

If you do go that route, keep in touch! Its expensive and difficult, but its pretty much
my favorite type of work :)
 
That tracking looks great
I have 3d/motion tracking as the next thing to get into
there's a hugh community that creates short 3D animations and images and a very big forum on CG society with support for almost any software package (It's like DVXUSER for computer graphics...)
 
Hey Jim, mind exporting a still of what your track points were? Or did you just clean up the shot and run it on auto? Apologies if you covered this already, I just skimmed the thread and didn't see it. Nice work in any case.
 
danny dale said:
i know the kid (16-17) who did these tutorials... you should check out his site -

http://www.peerlessproductions.com/

he does some pretty amazing stuff.
Click to expand...

Danny this Kids amazing...17 huh. Well I guess I remember creating dance music at that age. I'll tell you along with the HVX and tracking becoming more available it just makes for more possiblilities.:)
 
dougspice said:
Hey Jim, mind exporting a still of what your track points were? Or did you just clean up the shot and run it on auto? Apologies if you covered this already, I just skimmed the thread and didn't see it. Nice work in any case.
Click to expand...

Sure, here's a view of the project... viewport on the left shows the garbage mattes to keep the biker and other folks out of the track, also shows the automated track points. View on right is the cloud of points generated by Icarus that can be exported to your 3D package for reference. Also shows the camera path...

http://ftp.datausa.com/imageshoppe/outgoing/HVX/ICARUS_screenshot.jpg

Jim Arthurs
 
Jim Arthurs said:
Sure, here's a view of the project... viewport on the left shows the garbage mattes to keep the biker and other folks out of the track, also shows the automated track points.
Click to expand...

Looks like the auto-track really latched onto a lot of T-Junctions but the features
visible on that frame look nice and solid.

Where is the compression hit on the HVX's image btw? I'm shocked at the amount
of noise in the blue channel for most of the 1080p footage I've worked with. I
generally replace the blue channel with overall luminance if it ends up being
troublesome.
 
escozooz said:
Have you tried PFMatch? Its the embedded Shake version.
http://www.thepixelfarm.co.uk/products/products.aspx?PID=4
Click to expand...

No, but I've no doubt it's pretty solid, as Icarus has never failed with a little help, and the FPTrack, etc are all many, many generations past Icarus from the same developers.

In general, I've found 3d tracking (and 2d tracks within the 3d tracker, using all the auto features for pan tilt) more useful than 2d trackers in compositors. They all have their best uses, of course, but 3D tracks can really be useful for the "computer monitor/viewscreen" kind of corner pinning work... the edges can go out of frame with no worries. Of curse if you just need a simple stabilize or track a single feature, no need to go to the 3D trouble...

Fun stuff.

Jim Arthurs
 
Greggl said:
Where is the compression hit on the HVX's image btw? I'm shocked at the amountof noise in the blue channel for most of the 1080p footage I've worked with. I generally replace the blue channel with overall luminance if it ends up being
troublesome.
Click to expand...

Funny thing that... the clips I've worked with so far... sometimes the red channel is the noisest and has the most compression! I can't get a bead on it yet.

The Z1 had a very clean blue channel, but that's like saying an ugly dog has a shiny red collar on.

Jim Arthurs
 
Jim Arthurs said:
Funny thing that... the clips I've worked with so far... sometimes the red channel is the noisest and has the most compression! I can't get a bead on it yet.
Click to expand...

SW:Ep2 had a blue channel that was like sandpaper.. 1080p from the first of the
Sony F900s and the bluescreen footage, though fantastically lit, was more difficult
to work with than I would have ever anticipated. Lots and lots of roto work.

VFX is still one area where I prefer film originated footage.
 
Greggl said:
SW:Ep2 had a blue channel that was like sandpaper.. 1080p from the first of the
Sony F900s and the bluescreen footage, though fantastically lit, was more difficult
to work with than I would have ever anticipated. Lots and lots of roto work.

VFX is still one area where I prefer film originated footage.
Click to expand...

I heard rumors about that... that's not the kind of PR stuff you hear in, say, Cinefex, where everything is rosey rosey... :)

I don't know how the crew that did Sky Captain survived; original F900 off of tape as well. Lots of soft glow added later can work wonders...

CafeFX guys had major issues on that show, as well on SpyKids 2 & 3 with original HDCam format.. though they said the F950 and SR was a major improvement when they worked on Sin City, as good as any film scan they had seen over the years.

I've seen great film scans and agree, but all the Cineon sequences I've delt with lately have had blue channels that look like the dot pixelation filter from photoshop... mostly high speed night stuff.

Oh, one trick with a bad blue channel; replace with green channel and it works fairly well for all screen colors except saturated yellow and magenta. In fact, doing this can replicate the general look of an "old school" film bluescreen shot. The original Ultimatte was just an electronic version of film's Color Difference Matting technique. Same guy behind it all.

Oh, and the HVX makes good pictures, just to keep on thread.

Jim A.
 
Jim, have you tried replacing the green channel ever? I've tried various approaches in photoshop with the luminance channel but haven't gotten it to look quite right.
 
jung kyu said:
hi
i did a test on hdr-hc1

http://qlove.co.kr/1/1.mov
it's very simple track test with teapot.
it's not perfect..i need to practice more :(
Click to expand...

In shots that lack a lot of parallax, its going to be extremely difficult to get a solid
lock. You've got close to a worst-case scenario going on in that clip. It all depends
on what you're tring to add into the scene however.

Some things to try... you can stabilize the plate, add in your element than add the
handheld back in.. this would be an entirely 2d tracking process. If its a small element
like the teapot, you could track that directly to the element you're locking to, like
the posts with a 3 point track.

If you need a full 3d track for a virtual set extentions, etc.. then most of the auto
trackers are going to fail with their default attempts. You're going to need to make
sure that the software is ONLY exaluating good, solid tracks at various depths and
on different planes. Then you're going to need to weight those tracks to 'bias' the
solution toward the foreground tracks and your good mid-range trackers. Shots like
this are where having 'reference' frames from other angles really come in handy.
 
Shaw said:
Jim, have you tried replacing the green channel ever? I've tried various approaches in photoshop with the luminance channel but haven't gotten it to look quite right.
Click to expand...

Yes, but what you want to do is copy the green channel and use it to replace the blue channel. This works well for a range of colors, but you can't get saturated yellows and magenta just doesn't work. Another trick is to just blur the blue channel and half mix it with a copy of the green...

Now, in old school film bluescreen, the "cheap" shots would stop right there, and you can see examples of this with some of the model spaceship photography of the late seventies, early eighties. Keep the ships grey and stay away from yellow/magenta. I recently saw one of the later Superman movies and it was obvious they were just shuffling records around on the elements.

There is a way to return those colors, and that's the basis of Color Difference Matting. You create extra yellow by boosting some densities... good gosh, this is the first time I've thought about this stuff in years. Honestly, until you've had to try a bluescreen shot on film you don't know the sheer pleasure of messing around with sliders and seeing results in front of your eyes.

BTW Jung Kyu, thanks for sharing! I love the feel of the colors of that clip you were working with, and agree fully with Gregg's suggestions. Based on the little range of movement and the small size of the element, 2D tracking is the way to go..

Jim Arthurs
 
Oh certainly. I was just curious about using this methodology with respect to a greenscreen (which I use instead of blue). I wish I knew more about bluescreen effects with film. I'll have to try googling it - see if I can't come up with something. Do you know of any good resources off the top of your head?
 
Shaw said:
Do you know of any good resources off the top of your head?
Click to expand...

Ron Brinkman's book, The Art and Science of Digital Compositing is a great primer
for the digital process. For chemical techniques its a bit more obscure. My old ASC
manual has a great breakdown of the travelling matte process. The old Kodak
documents relating to their 5295 stock also have some neat info about the
refinements and necessities.
 
Thanks Greggl. I'm quite familiar with the digital process but I've always wondered how it was done chemically.
 
The absolute best reference on the old school film techniques is Raymond Fielding's"The Technique of Special Effects Cinematogrpahy". Libraries should have it if you don't want to buy, from Focal Press.

As to greenscreen done photo-chemically, well, it wasn't common. Maybe two or three shots that I'm aware off. Some shots in Jaws 3D, if memory serves. The process was bluescreen all the way because the industry understood the steps and the film's emulsion layers were best suited for it.

In fact, for film work, you'd NEVER use a blue painted wall or fabric, the purity of the blue just wasn't high enough. On the movie Willow, ILM used a blue painted cyc for freedom in shooting the actors quickly, and the difficulities in pulling a good matte off of the little fairy characters caused massive problems.

Most film bluescreen work was done with "transmission bluescreen", which is a blue translucent material lit from behind. Passes only 425-450 nanometer blue light. Very pure. I still own a small 4 by 3 foot screen.

Film bluescreen was as much luck, as an art or as a science, and demanded close cooporation with the lab processing all the intermediate b&w material. The slightest change in processing temp, or the age of the proccessing chemicals could spoil a matte or change its density and ruin the shot. Film stock unless it's Estar based will shrink or contract, throwing a matte alignment off. The same shot run through the optical printer on a different day will come out differently. It's totally insane. The big FX houses had their own processing equipment on hand for doing their own comps, it was that critical.

So, when you see a movie from the 70's/80's/90's and the mattes aren't perfect, cut those guys some slack. The optical cameramen were guys at the top of their game, with pressures and finicky tools to work with. When you do see GOOD compositing work, such as The Abyss, or any of the 65mm bluescreen mattes from Boss Films just know how difficult it was to get there.

I've really rambled off topic, but sometimes it's important to know where something started from to know where it's going. Maybe I'll get a thread going somewhere else and we can continue the discussion? I'm sure there's lots of folks with old school experience interested in rambling on...

Regards,

Jim Arthurs
 
You must log in or register to reply here.
Back
Top