A good solution for tracking stereoscopic shots?

[djdeluxe76]

Hi,

I am quite new to the world of stereoscopic imaging and specifically comp workflows. I have seen the new stereo support for Nuke v5 and also there’s FranticFilms Awake for Fusion that has similar support for a stereo workflow. Well that covers that – but what about a tracking solution for tracking the greenscreen shots? Is it as “simple” as adding enough tracking markers for all the important data (i.e. focal/convergence point markers, subject markers and random bg markers)

My research led me to the well respected 3dequalizer which is (judging from the freely accessible online tutorials) very nice indeed… but 10k a license is too much for our budget unfortunately.

So the question becomes:

Will a more “standard” tracking solution in the range from built in tools (we’ll be using Fusion although Nuke is being considered too) to the likes of PFTrack or similar be enough for tracking stereoscopic image data?

From what I understood shots where the camera or the subject moves need to get tracking the convergence point right to create a believable stereo comp so naturally my interest lies in tracking solutions or workarounds that are able to calculate the convergence point to recreate a moving subject or camera. The interocular shift between the two cameras could presumably always be roughly keyframed for our shots.

A very good article I read on the 3dequalizer website about a stereoscopic feature film case study revelaed a lot of details one should plan for when attempting to track stereo image data.

Thanks for reading through my post, I apreciate your time.

DJ

p.s. Searching for Stereoscopic I found a very informative reply by Danimator in respect to dealing with greenscreens in a stereo shoot… thanks for that.

[amit Dang]

Tracking a live action stereo plates can be tricky but you can achieve solid results by following a few tips. For starters, most stereo shots or most shots should have camera information from the script supervisor or DP. You will need your usual information like height, move, angle, tilt lens length Etc. The more you have the better the track. You should also have information on what the interocular or camera interaxial has been set to. This is the distance that the center nodal point of each lens is in relationship to each other. For most live action shots this is the same as human interocular distance of 2.5 inches or 65mm. Also note if the cameras are toed-in or have a moving toe-in though the shot.

Now you would just track your shot normally on the left eye only. Once this is locked in and you have a solid track, you can create the other eye.

Next start by adding another camera with the same focal length, field of view, etc and parent it to your tracked cam. Now offset that camera on the x axis by the interaxial spacing that matches the live camera.

At this point it may be a perfect match, or you may have to make some slight adjustments. If your doing a show that uses the Cameron/Pace rig, then you have to deal with animated or moving points of convergence. Now equalizer will help you with this, but I find the initial track usually will get you very close and most anomalies can be fixed in the 2D comp.

[Wally Rodriguez]

Hi Danimator,

Thanks for checking out my thread. Apologies for not replying earlier but I have been so into the project I didn’t have any time at all, more so since we got rid of the tracking idea altogether and started producing full CGI for those problem shots and the deadline even got closer… tricky but very very interesting project. This whole stereoscopic thing is so cool when I’m done with this project i’m definately gonna spend some time studying this artform. Also let me thank
you for your detailed explanations I really appreciate that you let me and others in the know for free (On a side note: Every person I’ve been talking to lately especially companies specializing in stereo shootings were close-guarding their secrets to very extreme extents – it was frustrating at times I can tell you)
During my initial research phase I found the following links which helped a lot in understanding the difficult parts:

Of descending importance:

“How a 3-D Movie is made”

http://www.the3drevolution.com/3dscreen.html

“Calculating Stereo Pairs”

http://local.wasp.uwa.edu.au/~pbourke/projection/stereorender/

“INSIDE Quantel: Stereoscopic 3D: The Next Big Thing” (incl. a nice glossary about stereo 3-D)

http://www.quantel.com/site/en.nsf/HTML/LSOV-75GAK6?OpenDocument

Regarding Quantel, there seems to be a turnkey workstation designed for stereoscopic edits named “Pablo” – it might be old news but I hadn’t heard of it.

There’s a small web movie showcasing polarizing projection and the workstation here:

http://news.bbc.co.uk/player/nol/newsid_7210000/newsid_7214300/7214356.stm?bw=bb&mp=wm&asb=1&news=1&ms3=54&ms_javascript=true&bbcws=2#

And last but not least a very very good stereo camera plugin for CINEMA 4D R10.5 which has proven invaluable … you can even use enhanced OpenGL to show the CINEMA 4D GUI in stereo 3D which I found quite remarkable. It’s from a international company which specializes in manufacturing autostereoscopic displays.

http://www.spatialview.com/products.cfm?cat=99&id=192

I hope that those links will prove to be useful to anyone who is currently researching this old but somehow new again artform.

DJ

[Daniel Sanders]

Just to keep up on this
check
http://thepixelfarm.co.uk/
They have some new technology in this vein
that they will show at Siggraph this year
-Lyn-

[mariaclark18]

Syntheyes is a very solid tracker and added stereo tracking on its last version. The price is very competitive, starting at $400.
http://www.ssontech.com/

[Hal Wayland]

Is there a difference between “Focal Distance” and “Vergence Point,” or are they the same thing.

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