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November 1, 2014 at 11:57 pm #206371
Hi everyone! How are you all doing?
My name is Omar…I’m new here…I don’t know if this is the right place to post thus but I have been trying tot rack and solve a relatively simple shot for a very long time now and I have given it all I got at it and it just doesn’t seem to be working at all!
I have been trying to track and solve this shot that I’ve filmed myself and it doesn’t seem to be doing it correctly. Everytime I would track it it would seemingly do it well, the footage is by no-means horrible) but when I come to solving it , there is always drift and jitters on the ground plane. I can look in the Perspective or Point Cloud view and I can see that it is abit of a mess and not resembling the scene whatsoever. Not to worry I said, I originally thought this was due to the Rolling Shutter of my camera and thought I would re-shoot it with a Global Shutter instead of pouring more days/weeks into solving an unsolvable shot.
What annoyed me as well was that I also placed a good few dozen User Features throughout the shot and made them into ‘Tracking Guides’ and tracked the shot with that, but it still continuously failed at the Solving in a particular area…however what was interesting to see was that the Point Cloud was slightly more accurate but the motion path gradually got worse as the shot progressed.
I went ahead to re-shoot it with a CCD camera, quality is of course not on par with larger sensor cameras but reassuring to not see any ‘Jello’ nor was it terrible, it was definitely usable.
I have also taken the steps to:
– Take note of the Focal Length and calculated it with the Wide-Angle lens attached.
– Film progressively at 25p and at 1/100th shutter speed.
– Shot my set-up on a Lens Distortion Grid (effectively correcting the overall geometry of the image)
I thought I was now onto a winner and went ahead to import the shot, setup my parameters for the Track and the Camera, undistorted the image (which looked pretty nice to be honest ) and went ahead inputted well over 90 USER FEATURES as tracking guides and tracked the shot which went solid.
When it came to solving…once again it just could NOT solve whatsoever! Albeit it did do a slightly better job due to Global Shutter (dream finally came true) but it just for the love of God not get through all the way till the end. I have even lowered the threshold to remove/reduce ‘red trackers’ and even raised it up to use all the trackers but I either get a solve with bad solution or a failed solve completely. Not to forget to mention I manually removed trackers from ‘highlights’ from shiny surfaces from cars that would result in giving me ‘false positives’. What was interesting as well was that when I would solve without the trackers, it would work but still comes out incorrect.
I have been at this for sooo long I just really don’t know what to do anymore, and I really do need to know what is going on. I’m sorry if this is quite lengthy but I just wanted everyone to have a good idea what I have been doing and the measures I’ve taken to get things right.
I just don’t now what I’m doing wrong and I would really really appreciate it if anyone here can help me out with this or if anyone could advise me what I might need to do to solve this.
P.S. I’ve also included a link to how the shot looks like to probably give you a better idea. I hope it helps!December 16, 2014 at 10:55 am #220253
Hi there Omar.
The first thing that popped in mind was the Film Back.
If you’ve not set that correctly you’re not going to get a solve… pretty much no matter what else you do.
pfTrack might apply an automatic setting in the input node but its based on a guess.
Same goes for the lensgrid you used to undistort the footage.
Go over the specs of your camera.
Make sure you know the filmback of said camera.
Is it shot on a full frame/ cropped sensor.
Manufacturers website should have the specs on hand (or just google it).
Manually setting (checking it at least) the filmback of your inputNode is the first thing I would do.
hope this helps,
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