How is this done?

Janos Belik · November 1, 2008

Hello folks,

I have seen a documentary where this unique technique, or trick have been used which blew my mind away. There were many scenery shots where time laps was combined with a camera move at the same time. Camera seems to be on dolly or jib, sometimes even areal shot from the helicopter. It is moving slowly about 30 in above the lake, along the steep cliff,etc. At the same time, clouds are moving fast (time laps). Does anyone have any idea how this is achieved?

Thank you so much

David Rakoczy · November 1, 2008

Motion Control

Will Earl · November 2, 2008

A few productions are starting to combine time-lapse photography with digital-matte painting techniques to do moving timelapse shots. Ghost Town has a shot utilising this technique and I've seen a few time-lapse shots of mountains using it as well.

Janos Belik · November 4, 2008

Motion Control

Thank you David for your response and for the link.

Cheers

Janos Belik · November 4, 2008

A few productions are starting to combine time-lapse photography with digital-matte painting techniques to do moving timelapse shots. Ghost Town has a shot utilising this technique and I've seen a few time-lapse shots of mountains using it as well.

Thanks Will for your response. So how could the camera movement be done by matte painting. Does it mean that the final image is basically a combination of video and animation? Or how does it work?

Will Earl · November 5, 2008

A lot of digital-matte painting work these days is a combination of 2D and 3D work - 2D images projected onto 3D geo. In this case the real camera is lined up with basic geometry representing the scene, the image is then projected onto the geometry. With the projected image baked onto the geo, it's possible to use another camera to create a new camera move.

Here's a rather simple example showing it in action...

Any areas that can't be seen from the original POV of the camera need to be either painted in or photographed from a different angle - multiple projections and image sequences can be used to create the effect.

brett gober · November 6, 2008

We build a pan tilt motion control remote head that is timelapse capable.

With full controller unit starts at around $17k.

Simple jib packages start around $13k, but no timelapse.

Rentals through www.pacificmotion.net

Around $300 a day rental.

Hope that helps a bit...

Hal Smith · November 8, 2008

Here's a rather simple example showing it in action...

Hi Will,

I looked at several of the 3d projection examples on youtube. It's my impression that there are perspective errors in the ones I looked at. It seems that if one doesn't map everything in the background image that as the camera moves there are relationships in the image that should be changing...and are not. I think a formal way of stating that would be that the 3 point perspective vanishing points in those 3d images are not rotating and elevating as they should.

Is it safe to assume that at the level of major features that digital artists involved have to spend a very large amount of time locating 3d image points so that perspective does change properly with camera moves?

Will Earl · November 8, 2008

You will get errors in perspective if you don't project the image properly. For example if the model accuracy is off or lacks detail to give enough parallax. Distortion in the textures can also cause problems. Most productions will do a LIDAR scan of the set or environment to try and reduce any issues with model accuracy or detail and we'll work with a reduced version of that data or even a rebuilt model based on that data.

There was one film I worked on where they had a shot of the camera flying down the side of a building. The building was a detailed CG model but the street below was an image of a street that had been projected onto a flat plane. At the start of the shot it looked fine, but as the camera approached the end of the shot you could start to see that the trees and the parked cars on the street were flat against the ground.