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imynderup · Joined: 12 May 2010 Posts: 2

Hi all,

I had my first go at positioning markers for a green screen track. Unfortunately, we came up with the idea to "track" these shots after the fact. So I drew on what I remembered to set up markers as best I could.

Here is the shot in question:

http://www.mantrahouse.com/_uploads/GreenScreen-Track-Test.mov

It seems as though I can get a semi-decent track for about half the shot, then everything goes bust. I watched the tutorial on green screen tracking with the cat, and various others.

How should I tackle this? This is my first real project trying to get a camera solve. Any help/advice would be immensely appreciated! I really need a starting point and what to watch out for.

~Ian

rtep · Posted: Wed May 12, 2010 7:24 pm Post subject:

Don't use any autotracking on shot like this!!!!!!!!!!!
Don't use inbuilt greenscreen enhancement abilities.

Take the shot, quickly track manually placed points ("supervised trackers" in SynthEyes terminology) on everything you see in the image and hit solve.

Easy easy bish bash bosh. Plenty of markers to track. Some stuff to track in the foreground (including the standing dude).
No motion blur or grain or anything else difficult... Only the defocus on the markers at the end of the shot may cause you trouble but no big deal.
Possible lens distortion doesn't have to bother you in this shot.

Have fun.

Petr

rtep · Posted: Wed May 12, 2010 7:28 pm Post subject:

One more thing:

can I use this footage to make a very short videotutorial on tracking a shot like this?

It bothers me that sometimes people are struggling with a shot like this and sometimes they even blame the software....
(I'm not talkng specifically about you, it's about many newstarters in general)

Thanks.

damian_d3 · Joined: 16 Apr 2008 Posts: 61

Tutorials!!!

If you can't the material drop me a mail. I guess I have some similar shots that actually belong the company. Maybe I can send give them to you for a tutorial.

Cheers

Damian

rtep · Posted: Thu May 13, 2010 6:48 am Post subject:

imynderup: can you explain what approaches did you try???!!!!

Because I just opened the shot, clicked the auto button and it gave me a pretty good track!!!!
Finalizing it to a production-usable result would require some more work (simplyfiyng the camera path as much as possible etc)

but the basic camera solve was there all the way through

from what you said, "I can get a semi-decent track for about half the shot, then everything goes bust", I understand that you had some major problem...

Were you trying to use the inbuilt greenscreen tool or were you masking the standing actor? WRONG!!!!!

just open it, hit the green AUTO button and then try to improve what you get

well but yeah tracking it manually will of course give you better result, I may still record the video but not today, I'm kinda busy.

imynderup · Joined: 12 May 2010 Posts: 2

Wow, thanks for your responses!

I tried it both ways. Just hit auto tracker and let Synth do its thing, and after watching the green screen tutorial, tried it his method. When I say the "shot goes bust" It's like it's solving fine right up until the end and the trackers completely lose the track.

This is really my first go at using Syntheyes and indeed a matchmove, so I am stumbling a bit. I will try your suggestions and see what happens.

You can absolutely use this footage for a tutorial. (I'll be your first customer!) I just ask that you credit the footage.

Ian Mynderup
VFX artist/director
Mantrahouse.com