Chroma key project wih 3d tracking

Anders Holck

Anders Holck

Well-known member
Hi.
Just wanted to show you my big new chroma key project (I did another one last year if you remember the Carlas video)

The shoot was done using my HVX-200, recording in 1080p25, and just improvised a move on my Steadicam.

The camera was tracked using Syntheyes, then exported to AE7 as a maya scene.
The keyer was keylight.

This is just the Intro, I'm working on the other 15x1 minute segments :beer:

The graphic elements was done by the talented GFX artist Georg Rune Andersen, and composited by me.

The final Intro can be seen here

The raw shot with the tracker targets can be seen here
 
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That was cool, Anders. :thumbsup:

I almost prefer watching the raw shot because it is so clean.

How do those green balls and the tape on the walls come into play to help with the tracking?
 
The tracker targets gets picked up by synth eyes, which after the track pass automatically calculates the imager format, focallenght, the position of the trackers in 3d space and creates a virtual camera that matches the camera move.
You want to spread the targets in depth to help solving the scene.

This was my crash course in 3d tracking, so if I were to do it again I would chose a more contrasty color for the tracker targets. The tracking process was a bit to manually assisted with the current targets, but the keying was extremely easy as all targets dissapered in the key, without the need to paint them out as a contrast color would have required.
 
Coool. The great Anders uses Syntheyes. I am happy with my purchase!

Nice work, as always, Anders.
 
Anders!

Fantastic as usual! I love the color grading on the piece.

I hope you can share the before/afters from all of the segments.

I think the trade-off between the tracking effort vrs the quicker key without needing roto was a good compromise. I pretty much use manual trackers in Syntheyes anyway.

Regards,
 
awesome dude... just awesome!
It looks like those balls suspended by thin nylon string?
Did u put this rig together yourself? If so what balls did u use for this?
And suggestions on how far apart or best positions for this ball placement
Thanks and great work!
 
The balls are white 1.5" polystyrene balls from a hobby shop. Painted with a lighter shade of paint than the backdrop.
They are attached to thin nylon fishing lines suspended from the light rig.
Lights are: Three spacelights on dimmers suspended from the ceiling, a side kicker and a low flourescent fill on the floor.
It's always a compromise to light for 220° camera coverage...

You need at last 3-8 trackers in the frame at all times depending on the camera move, so depending on the shot you can adjust the amount of tracker targets accordingly. Having targets in multiple planes also helps Synth Eyes solving complicated segments.

My basic workflow inside Syntheyes is to track 4-6 targets all the way through the shot and then do a quick solve. That usually solves about the first 1/10 of the shot and I then continue to fill in with more targets until it solves all the way.
Takes about 4 hours for each segment.
 
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Is SynthEyes still able to pick out the trackers by itself, or is that a manual process that you need to keyframe?
 
With this low contrast, you have to do assisted tracking.
You manually put a tracker onto a physical target and press play, and synth eyes tries to follow that target. If the tracker gets covered by the actor you manually have to turn off that tracker and reenable it when it reappears. If the tracker goes out the edge of the screen Synth eyes automatically turns it off, but you have to manually turn it on when it reappears.

Synth eyes has a view called lifetimes where you can see how many trackers you have on every frame on a timeline, if there is to few the frame has a yellow or red overlay.

Tracking long shots like this using low contrast features is very hard. Especially the combined motions on the steadicam makes it very hard without targets spread around the scene in depth.

Making simple effect shots on normal footage with lots of feature targets is much easier and can be done automatically with very little rotoscoping of unvanted motion (Like actors or other objects in the scene that doesn't affect the cameras motion)
 
Here is another segment, it's a little different but same idea...
http://holckowen.com/stuff/holcksample2.mov

(Notice the sled hit a cable at 15 secs in)

l_3e489f08be75d5fdfd3c7da371cff0f5.jpg
 
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Anders, again.. very slick work! Thanks for posting.

Your work is inspiring to an up an coming composite artist :thumbup:
 
Hey Anders,

Looks fantastic. Congrats on your first MoTrack shot! The track looks great and the composite it top notch. I'm sure you've caught it but mid way through you have a hole in the bottom of the spray can where it reflected your green. Nice effect on the spray by the way.

I notice in your still that you have the rear LCD removed from your HVX. Is it for weight/balance on steadycam? I currently have my HVX torn down for cleaning and to add a flip switch for the LCD. I was contemplating leaving my rear LCD off as well. Curious about your reasoning.

Keep up the great work, I still show your video from last year to people, it always gets rave reviews. I can't wait to see this one when finished.
 
Yes AE7, running under Rosetta PPC Emulation.

I removed the Viewfinder to investigate if it was possible to make an extention cord to be able to mount it on the body when shooting with my M2 adaptor. Never really got that going, but I found out I didn't miss the VF, so I just kept it off.
 
Anders, great work. You tackle these projects with clear vision and precise execution. I really like the art design and the compositing technique.
 
Anders Holck said:
With this low contrast, you have to do assisted tracking.
You manually put a tracker onto a physical target and press play, and synth eyes tries to follow that target. If the tracker gets covered by the actor you manually have to turn off that tracker and reenable it when it reappears. If the tracker goes out the edge of the screen Synth eyes automatically turns it off, but you have to manually turn it on when it reappears.

Synth eyes has a view called lifetimes where you can see how many trackers you have on every frame on a timeline, if there is to few the frame has a yellow or red overlay.

Tracking long shots like this using low contrast features is very hard. Especially the combined motions on the steadicam makes it very hard without targets spread around the scene in depth.

Making simple effect shots on normal footage with lots of feature targets is much easier and can be done automatically with very little rotoscoping of unvanted motion (Like actors or other objects in the scene that doesn't affect the cameras motion)
Click to expand...


Great commentary, Anders!
Nevermind I found the info!!! LoL
Thanks again for the info!
 
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