Tunneling a television

[ajcgi]

Hi all.
First post of many I hope.
I'm moving across to vfx from doing 3d graphics of other less realistic nature. This is my first attempt at matchmoving using Syntheyes. It appears to be floating still to my eyes but that may be an effect enhanced by the area of black still present around the tunnel.
Very much WIP though. I want to add many more cracks to the glass, totally remove the markers I used on the walls whose shadows are still causing issues at times and get the matchmove spot on. Also thinking of adding a cart into the tunnel, a few sleepers etc. Will revisit materials and lighting too as they are iffy at times.
Any suggestions?

Alex

[ajcgi]

Ok I've added a cart. Still need to revisit a few things as before. Today I was working on the Syntheyes file and reading a tutorial or two on the matter. It may be a whole lot easier for me to shoot this again with fewer markers on the walls (only using about 5 of 15 the rest are useless), some on the screen itself and some more on the floor.
All good fun though! Still enjoying this.
Vimeo of the cart in place. Mp4 attached too.


http://www.vimeo.com/2699061

[Dotcommer]

Nope, its not your eyes, it really is bobbing a weaving with the camera a little.

A rule of thumb for tracking if you're selecting track points manually is to have 7 to 8 points being tracked on screen at any given time. Don't saturate the program with too many tracking points, and don't deprive it of enough to do its photogrammetry algorithm properly.

It seems like the bobbing is happening for only part of the movie, so start from the beginning and look at all your current tracked points up to about half way into the movie, and see if any of them are swaying away from their marker. By the time half of the clip goes by, it looks like new tracking points have been added or used, so the track seems better closer to the tv.

[ajcgi]

After a long break from this project, I pushed aside some time, got myself a camera rather than borrowing one, and shot this in such a way as to give Syntheyes more to work with. It's pretty much where I initially wanted to take it, though looking at it today, the chain link fence and gates are somewhat dominating and clean. Still a tiny bit floaty, but my eyes are only picking it up on the dirt on the tv. I can probably correct that in the after effects projects.
Critique and suggestions appreciated!
Alex

Vimeo:
http://www.vimeo.com/5139415
(Vimeo was gonna take a while to convert the file when I submitted this, so be aware... it's coming!)

[avillabon]

I liked the original camera move better.

Alex

[ajcgi]

I had trouble getting the original camera move to solve well. Originally I put it down to iffy footage, but I shot a similar move this time around too and it was actually worse. Course this may be due to me being a rank novice in terms of 3d tracking. I often find that I've tracked a sequence, all looks fine, but then the 3d geometry just doesn't hold still.

I agree with you that the move was better as apart from anything, you can see down into the tunnel.

I'll be carrying on with this during the week I think, so any suggestions are welcome.
Cheers
Alex

[ajcgi]

I've finally had a chance away from work to revisit this project. I've reshot it with a move closer to the original piece, tried my hand at a day to night type conversion, with a sudden lights on situation.

There's a mov attached, but also a Vimeo at
http://www.vimeo.com/6701319 which is darker for reasons best known to Vimeo.
I'll look at adding shadows, dirt etc onto the tv itself as I haven't done that yet this time around. The 3d's not rendered at its best so you'll see the occasional flicker in the grass and shadows. One or two hiccups are still in the tracking too, but you'll get the gist :p

Also I've been toying with shooting footage where I fall over backwards in surprise at the bats coming out the tunnel. I shot it in the same way as the previous footage, but with post it notes on the upper reaches of the walls and on the ceiling to try to give Syntheyes a point of reference, but things turned out tricky. The initial falling back caused so much blur in each frame I had to manually position all markers and it turned into a bit of a mess. Something for another time perhaps.

[tobyjt]

Cool stuff, good work, but if I may offer some observations;

-I think there is too much light on the foreground of the CGI, I think there needs to be a blend of lighting from the live action and CGI, at least on the plane of the TV and forward to it. Notice how it works better when the lights are out?

-I think there are slight hiccups (extremely slight) in the solve, although you'll probably get away with it if it composites nicely in all other respects.

-The edge of the CGI to the TV is really giving it away, but all I can suggest is try something else (maybe more cracks, with the CGI going into to cracks, if that makes sense?) Notice how it works better when the lights are out and you can't 'SEE' the edge?

Toby

EDIT: nice work on the focal matching and the actual edge of the broken screen, and the noise matching if you've done that too?

[Mata]

Looked pretty good

In the 3rd update it just looked too dark almost in the beginning. Almost losing everything. I say Keep it more in the day. The bats need some work, lastly I would move the mine kart in the very front. Its blocking the view leading down the hole.

Other then that its coming along. :)

[ajcgi]

Thanks very much for the feedback on this. I only just noticed the comments unfortunately, but I'll bear all of it in mind when I make my next update in however many weeks time lol!
In the meantime, someone suggested to me to reverse things a little, ie the sequence starts at day then moves into night. It's all a bit clichéd but I'd be interested to see what you think of this approach. I've used similar footage so there's still no visual jump back from me when the bats appear.
The edge of the cgi onto the tv bugs me somewhat too. ;)

[ajcgi]

http://www.ajcgi.co.uk/xs/4th_go_00240.jpg

Another long delay and another update! All I've changed since the last render is the edge between the tunnel and the screen itself, making it look more a part of the TV now. That and I've moved the cart back a bit. I tried a version without it entirely but that seemed very bare to my eyes.

Same Quicktime as before but with the new entrance:
http://www.ajcgi.co.uk/xs/4th_go_00149.mov

Once the sun comes out again I'll reshoot the background footage, keeping the room tidy of course ;), with some kind of reaction to the bats as well. I have a lighting issue with the current footage. It was quite a dull day leaving everything looking fairly flat, hence I ramped up the contrast so much in the composite. I'd rather light it properly to start with this time and avoid too much correction as ultimately that is breaking the illusion a little imo.