Anyone use PFTrack before?

O

oneinfiniteloop

Veteran
I'm using PFTrack to track and solve a shot, and also create a depth map. I started it around 2pm today, and the track and solve took aroun 3-4 hours, and the depth map is taking around 2 hours. Anyone ever experience processing times like these?

I'm using a Mac Dual G5 with 1.5gb of RAM. I'm thinking I'll need a small render farm to get even more complex shots done in a reasonable time!
 
Something is definatltly wrong. If you're seeing solves that long, you've got issues
with what its filtering out as bad or questionable data.

What rez? Got a clip of the shot?
 
I can't post a clip because of non-disclosure reasons. It's DV 24p. It's a really dark shot with most of it in the shadows...don't know if that's part of the problem.
 
Oneinf, if it's just for track data, couldn't you lighten it up and really pump up the contrast just for the software?
 
Adjusting the gamma works, as does replacing noisy channels. Piping
overall lumanance into the blue or green channel can also help.
 
Yeah, I've tried that a few different ways, haven't got passable results. Everytime I try to bring up my levels the image gets washed out or falls apart. I had to slam my gamma just to figure out where certain features where on the person I was trying to comp. It finally finished the depth map last night, which is what I really needed to comp in the shot decently.

Maybe I went around the problem wrong, so here is what I'm trying to do. I have to be vague because of non-disclosure reasons so bare with me. I'm trying to comp an effect on a persons moving body part. The body part moves back and forth and the shot is a two-button medium shot with a rack focus, and dark shadows. The part of the body I'm trying to comp to is completely black and cannot be seen throughout the whole shot. A part of the body below it is always in the light so I usually try to track to that.

When I get the effect in place and then track it in, I don't feel a natural z-axis type movement from it. So, I thought a depth map would help sell the shot with body part moving back and forth along the z-axis. Only way I know is to generate one from a 3d track program. ANy other hints to help create a depth map? I guess I could create one from scratch, but the shot is 250 frames in length and that's a lot of roto work.
 
Yeah, I was trying to avoid that, tracking does a good job along the x and the y, maybe I'll try to animate along the z to match the depth where need be.

Thanks for the response. I'm going to have to get Tim Dobberts book on the Art of Matchmoving, this stuff is crazy. Plus, optical flow looks like something I would really like to get into.
 
if your video is gettting wrecked using levels to bring out contrast, use Duplicates with the Keying>Extract filter to isolate highs and lows. Then apply multiple instances of each with differing blurs set to multiply (for the dark icolations) and screen to bring back detail.


That could work.

ANYTHING has got to be better than roto.
 
Rapier_100a said:
ANYTHING has got to be better than roto.
Click to expand...

Agreed! After many hours I finally got a depth map, so I'm going to see how that works tonight. 2D tracking gets the shot in there pretty well, it's just that "kiss of love" I was after.
 
The problem with that is that you're creating artificial 'trackable' divisions that are actually differences in lighting levels rather than solid features. Those will slide
as perspective changes.

It sounds like you've got four issues here.

-moving camera
-moving object
-low light levels
-occlusions that will need to be roto'd for object integration.

Animating to the plate and roto-ing where necessary is easily going to
be your best bet... you wont get a good object track untill you get a
good camera track and unless you've got some good reference for your
object with known rigid distances for its dimensions, any z-data you
get will be suspect.

The trick to animating to the plate is in your pivots. You're going to need
multiple, indepent pivot points in a heirachy so that you can refine the
movement in passes. The first, 'top' pivot will be at the 'hinge' point where
your cg object will blend with the plate. From there, you'll be rotating/z
depth moving along the camera vector as the object moves in the live
action plate.

I still love doing this work in Softimage as its got such a great camera
axis move. Maya is a kludge. Not sure about the current state of
LW/3DS Max.
 
Greggl said:
It sounds like you've got four issues here.

-moving camera
-moving object
-low light levels
-occlusions that will need to be roto'd for object integration.
Click to expand...

Actually the camera is locked off. I was just hoping that the track/solve for the depth map would have been a little easier than roto, and I've always wanted a reason to work with some of these demos. I guess I'll be animating by hand.

Thanks guys!
 
The lockoff really does simplify, especially with lighting you element!

Best of luck.

I'm just finishing up a shot thats been around 6 weeks worth of work that
may actually end up on the cutting room floor. Roto'ing out a guy on a motor
cycle, moving the cycle to another timing/placement, erasing the old
rider/cycle, replacing stuntman's head with actor's head that was shot in
totally different lighting and a non-motion controlled 'simulated' move to
try and mimic perspective and scale change in the plate.. and its shot from
a moving camera car with no clean plate, camera information or reference
in broad daylight :) Easily the hardest shot that I've ever single handed.

I feel your pain :)
 
Greggl said:
The problem with that is that you're creating artificial 'trackable' divisions that are actually differences in lighting levels rather than solid features. Those will slide
as perspective changes.
Click to expand...

Didnt know that, and would have had to find out the hard way. Thanks for the heads up.

GOtta love this forum.

Greggl said:
I'm just finishing up a shot thats been around 6 weeks worth of work that
may actually end up on the cutting room floor. Roto'ing out a guy on a motor
cycle, moving the cycle to another timing/placement, erasing the old
rider/cycle, replacing stuntman's head with actor's head that was shot in
totally different lighting and a non-motion controlled 'simulated' move to
try and mimic perspective and scale change in the plate.. and its shot from
a moving camera car with no clean plate, camera information or reference
in broad daylight :) Easily the hardest shot that I've ever single handed.
Click to expand...


Dear god . . .

That sounds like a nightmare. :badputer:

As far as the state of Lightwave goes (from your earlier post), you don't wanna know.

I wish I knew Softimage.
 
Last edited:
When tracking the two things that you have to be very careful to avoid are 'T' junctions and highlight tracks.

'T' junctions are where two 'lines' cross and create an artifical point. Think of two
blades of grass that are a few inches apart. If they cross in an X or T shape, the
tracker will lock to that junction. The problem is that if you change perspective
on those blades of grass, that junction changes position and eventually goes away
from other angles.

Trackers will also lock to highlights and reflections on glass. These also tend to
'move' as the camera changes perspective or the object moves around. That
movement will throw off a tracking solution.

While we're at it, tracks also lose fidelity as they get closer to the edges of the frame. Subtle vignetting can cause the solution to 'bend' if necessary tracking points go into those areas. In some cases, you want to remove the lens distortion before tracking.

Finally, you'll generally see pops and bumps in the curves and solution on frames
where trackers come on and go off. Those bumps are re-alignments as the solver
is trying to logically fit the trackers into xyz space. That track that just came on or
went off is being 'weighted' heavily in the solution. The fix is to add more tracking
points to 'bridge' those on/off frames. In some software you can also adjust or even
animate the 'weight' of the trackers to lessen their importance in the solution.

Hehe... just a few tricks of the trade :)
 
Damn. Nice response dude. I need to get some tracking software for 3D. All the tracking I do is simple motion/stabaliztion and occasionally, corner pinning. Nothing like the 3D stuff you guys are workin.
 
Rapier_100a said:
Damn. Nice response dude. I need to get some tracking software for 3D. All the tracking I do is simple motion/stabaliztion and occasionally, corner pinning. Nothing like the 3D stuff you guys are workin.
Click to expand...

Yeah, this is my first foray into 3D tracking and it's interesting to say the least. I downloaded a demo of boujou bullet and pftrack. PFtrack lets you use the software for three days before locking up, so I figure I could pound out a shot to see how I like it.

Greg, what do you use for 3d tracking? I'm trying to decide which software I want to purchase and any help would be great. I use Maya, AE, and Shake, if that matters at all in what type I chose. I'm looking for something that not an arm and leg, I can't afford a full version of boujou 3!
 
Its capable. There is some funkyness with some solutions, but with any of
the apps, you start to learn what it wants then you feed it accordingly.

Its also a 10th of the price :)
 
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