Uturnpike’s drift

Premise

Mysterious rows of snow covered cars snake into the distance. What happened here? Was a neutron bomb exploded nearby? Were the drivers raptured away by the returning Messiah? Why are the cars bumper to bumper in both directions?

Unturnpike and Canyon Princess are scenes from my narrative short Daughter of God, (in progress). DOG is a dystopian, universe next door, ribald, surreal romantic comedy. Most of the action takes place aboard a big boat between three quirky refugees. Strangely beautiful and eerie scenes of nature reclaiming the earth provide context for their post apocalyptic hijinks.

I was just cutting my After Effects and Mocha teeth when I first gnawed this scene.

It all started when DOG’s B unit (Patrick and I) traveled to the abandoned stretch of Pennsylvania Turnpike in April of 2007. I’m confident our work inspired at least one other project to shoot at the pike – The Road with Viggo Mortensen.

On the Pike – Uncle Joe drifts down the asphalt river

Approach to an undisclosed location

Deep underground, the spooks bide their time

B unit grunt with expensive camera and an attitude – Patrick Kelly

Anyway, we spent a week filling P2 cards. One of my favs was cloud shadows moving over long stretches of empty pavement. Since there was slight camera shake, a solid track would be needed if I wanted to insert 3D cars. The original Mocha tracking solution was far from perfect. I thought the reel was the chance to get it right. I spent the better part of a week trying various approaches to no avail, much of that time repeating past strategies. We want to avoid re-climbing old curves, that’s why this blog is now dedicated to low level documentation. So standby for technical details…

The camera shake is slight, so theoretically there’s no motion parallax. According to Steve Wright’s tutorial, I can treat the entire shot as one coplanar surface. That means I don’t have to identify / track specific planes like the road, the distant mountains etc. However, the moving cloud shadows change the brightness of the features and that makes the track drift. When a feature is darker, the track becomes erratic. At least that’s what seems to be happening. I tried shifting between features with consistent brightness, extensive explorations with adjust track, even brightening the footage before tracking. The problem with Mocha is that I can’t find definitive text based documentation about how the tracker actually works under the hood, so there’s a lot of guesswork involved when trying different approaches. I pissed away too much time watching tutorials for hints about what’s actually going on.

The new track is really not much better, the cars just drift off the road at different times than they used to. I am prepared to admit defeat and pay for outside help to get a solid track. For now tho, there’s enough drifting snow and rousing soundtrack to distract attention from this glaring issue, but just barely.

Jonathan tinkered with the car renderings to try and amp up the reflections while retaining rich color, but he didn’t implement the 50 pixel expansion doohicky in time to make V 0.9. Again, another argument for keeping detailed notes.  It was three years ago, after all.

There are some improvements. By implementing a combination of garbage mattes and keys I extended the blanket of snow into the forest without having to hassle with the vagaries of tracking. I also made some adjustments to the fog and snow, refining my understanding of how z based effects work.

Uturnpike was Jeff’s favorite, and he can be a tough audience. I do like this scene too, but it’s definitely not up to snuff, yet.