Help with PFTrack 2011

[butlermagic]

Hi,
I'm new to the forum so I apologise if this is the wrong place to post this or if it's already been covered.
I'm quite new to matchmoving and up until recently I had been using PFTrack 5 I'm now learning 2011.
My problem is I'm trying to track some footage which I've managed to track quite well a number of times using the auto track however I find that I do get a slight amount of slip. To try and fix this I've added in manual tracks to try and lock it down however whenever I do this it totally screws up the track. My point cloud looks great up until I add the manual tracks to the solve after which everything looks terrible, even after refining it. This even happens when I start with manual tracks and solve them first. There should be a picture of this attached to demonstrate what I'm talking about. The footage I'm 90% sure is from a Canon 5D and I've tried to match the settings of the camera to this but still with "Unknown" selected just so PFTrack will improve upon it. I hope this makes sense.

Any help/advice would be greatly appreciated

Thanks

Butlermagic




[lirumlarum]

hi butler,

i would recommend using ONLY user features, as an autofeature cannot continue once a feature has left the frame and then re-appears...

Also you have to set the correct chipsize for the 5D (36.0 x 24.0 mm) and check carefully if you see any rolling shutter issues. If you do, apply the shutter fix node BEFORE the user tracking node...

You should also use constraints as your wall is perfect for that. By this you tell the tracker which points sit on one plane. This helps the solver tremendously.

Hope his helps

Timor

[butlermagic]

Hi Timor.
Thanks for the reply and your suggestions.
I have already tried to input the chip size but have only been able to use one of the measurements ie. 36 or 24 PFTack automatically puts in its own measurement on the basis of the first, which is wrong. Do you know how to fix this? Also could you explain the constraint tool you mentioned? Are you referring to the "orient scene" node and using the axes to identify x,y,and z?
Thanks again.

[lirumlarum]

In video mode the 5D of course only uses a 16:9 portion of the chip. So if you enter the horizontal value (36mm), pf enters the appropriate number, matching 16:9...

Regarding contraints: no, it´s not the orient scene, that is coming AFTER the solve. The constraints should be inside the auto track and the user tracking node. If i recall correctly there is a tab for the contraints. Create a new constraint (e.g. "left wall") select all trackers on the left wall and add them to this constraint...

[butlermagic]

Thanks for the advice lirumlarum I really appreciate it. It turns out the reason my user tracks were shooting off like that was because I wasn't hiding them before and after they'd started and finished tracking. The solver was still using them. I don't remember having to hide them in version 5 but it's been a few months since I've done any tracking.

Thanks for help again. I'll certainly be using the constraints tool that you suggested.

[lirumlarum]

Uh i know what you mean, i had to learn this the hard way too...it is not a very intuitive workflow i have to admit!

nice it´s working out now