Problem with Perspective

[Walter Soyka]

As a pure post solution, assuming you have tried to manually get both dolly shots as close as possible, I’d try the following:

1) Grouse about how easy this would have been to fix in production with motion control

2) Use 3D tracking on both shots, talent and windshield, to solve for the camera move

3) Analyze the rate of movement in Z-space of the camera in the talent shot

4) Use time-remapping to match the rate of movement in the camera of the windshield shot to the rate of movement in the talent shot

5) Hope it all works!

Maybe you can test this workflow before shooting?

Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive   |   RenderBreak [blog]   |   Profile [LinkedIn]

[Ryan Moser]

Big thanks to both you and Walter for taking the time to help me with my current struggle.

I’ve had some success with using a Bezier Warp to fix the perspective. I currently think the best solution may be to dolly with both shots. Time out the green screened windshield plate as close as possible and fix any sizing issues etc. via using a Bezier Warp. That way I can maintain the most resolution possible.

Thanks for the taking the time to share your knowledge and thoughts on the subject!

[Ryan Moser]

The reason the entire shot is so difficult is because it is a combination of practical effects. This is just the tip of the iceberg of the problems I’ve had to overcome. Thanks again for your feedback, Dave!

[Daniel Waldron]

I am very curious how this will work out. I’d love to see the end result and how it was achieved.

For an inexpensive motorized rig, check out Revolve Camera’s dolly. I’ve used it mainly with DSLRs, but I’ve seen larger rigs on it as well. I’m not sure how accurate the motion is from shot to shot, but I imagine it would be much easier to match than dollying manually.

[Matthew Woods]

Would it maybe be easier to 3d track the pivot points for the wipers in your dolly shot, then animate the windshield wipers in 3d space? It doesn’t seem like it should be too hard to animate the wiper movement. You would have a side benefit of having more control over the timing of the wipers, so that it doesn’t conflict with any of the action in the car.

-Matt

Need a quick break from motion graphics?
Try my game Constellation at:
https://www.paperdragongames.com

[Ryan Moser]

Thanks for the suggestion, Daniel. Unfortunately I don’t think the Revolve Dolly will be of help for this particular project. We need a large dolly that can support the wait of both a tripod that has a jib or some sort of extending arm attached.

Thanks again! I’d be happy to share the final project whenever it’s actually complete. Unsure when that will be.

[Ryan Moser]

I think your suggestion is probably the easier route. However it would conflict with the current practical effect that we have perfected.

One of the aspects of the entire shot is a bug splatters on the windshield. The driver uses the wipers to clean up the mess. The practical effect looks flawless because it’s basically as real as you can get. The changing of the color of the water and the smear of the bug as the wiper goes across it.

The problem with the practical effect has been tying it all together with the performance dolly move.

Thanks for yours and everybody’s feedback in helping me conquer this task. I’m happy to realize that it isn’t just me struggling to solve the solution to this. I would have been relieved, but also embarassed, to realize a really easy solution. If we are able to pull this all off at the level I’d like, I believe it will be truly impressive.

I’m definitely going to take your suggestion to heart and try some tests with it.

[Raza Ahmad]

I know this is probably photographically non-ideal, but:

The simplest option I see here is to only move physical (as in in the real world camera) in one shot, the one where you are dollying in to talent.

The second shot, camera with wipers, would just shoot it with a static camera, if you are using RED or similar you could leverage extra resolution here.

You 3D track your dolly shot, making careful note of lens length and height and marker distance (AND FOCUS POSITIONS!) to get a spacially accurate 3D Solve, then inject your windshield as a 3D layer between the virtual camera and your physical dolly shot, and use the 3D motion track + focus data to realistically blur out the windsheild imagery as your camera moves, ultimately moving past the layer via a very quick dissolve or single frame transition.

Not sure… that would be the $0 film school idea.

[Ryan Moser]

This is the solution I was planning to use. However in the test I did (the video with the iron that I posted) the change in perspective between a dolly move and a zoom move within a single composite looks unnatural. Time to test out some other ideas. If I knew how to use Nuke I believe this would be a fairly easy composite using their f_align plugin.

[Ryan Moser]

I personally received a lot of detailed and helpful responses to my past inquiry. I wanted to thank everybody once again that chimed in with their two cents.

I’m proud to share the arduous passion project that took so much time to prepare for.

https://www.amazon.com/dp/B071S8DH6F/

Thanks again for your helpful advice!