Nuke roto trackin question

[clayton]

Hi

Nuke noob question
Ive been trying to follow along with a tut from this site, and I keep runnin into an issue. The tut says to create a track, and then attach it to a garbage mask, but every time I do this, it moves the garbage mask off.

See attached. The tut doesn't really explain this well, or at least it didn't happen for him. Im using 6.1...with the root tool. Hes using 5.2, with the bezier tool. Is that my problem?

[nofxboy1234]

Maybe check what the reference frame is set to in the tracker. I've had something like that before and it was because I never set the reference frame to the frame where the tracker actually starts tracking the feature.

By the way, cool reel

[clayton]

Reference frame starts at 1....And the tracker never makles it that far away.
Its some sort of offset.

and thanks about the reel....

Working on my new one now....Whatcha think? Not too much new stuff, but it is what it is.

http://vimeo.com/18379137

[clayton]

And that is a badass roto reel....I need to make one of those....although the idea of rotoing individual hairs, gives me the shivers!

[nofxboy1234]

Haha thanks!

I like your new reel too. Especially the shot with the car driving down the street past the fireworks. It's got a nice holiday feel to it

I was wondering if you could maybe have a look at a problem I'm having with tracking too, haha. I hope you don't mind me mentioning it in your thread. Here is the thread: http://www.vfxtalk.com/forum/help-st...6.html?t=29296

[Seriphu]

It has to do with your center. When you link the center to your tracker it keeps your center relative to the shape you created but translates the center to match that of your tracker. Its habit for me now to track first apply the data to the shape then draw the shape.

The fix is what nofxboy mentioned, your reference frame has to be the frame that you drew the shape on. Basically your tracker translation and bezier translation should both be 0,0

[masky007]

It has to do with your center. When you link the center to your tracker it keeps your center relative to the shape you created but translates the center to match that of your tracker. Its habit for me now to track first apply the data to the shape then draw the shape.

The fix is what nofxboy mentioned, your reference frame has to be the frame that you drew the shape on. Basically your tracker translation and bezier translation should both be 0,0

Is this always an issue in nuke 6? I am very new here however i have done some roto with tracking and... no issues till now hmm?

[Seriphu]

Its just a matter of remembering to set the reference frame to the frame that your roto is in its correct place. The times I have problems its normally user error with a few occasions where the tracker just bugs out.

[Andreas.Jablonka]

maybe w eneed to explain what the reference frame does? as the name suggest its the frame all translations, rotations, scales are set to 0 hence no movement. every other frame has a value relative to this frame.

say frame 1 the track is on x0,y0 and on frame 10 the tracker is at x50 and y200. if you draw your shape on frame 5 the tracker will have values other than x0 y0 and thereby moving your shape a bit once you apply its data. if you shift your reference frame in the tracker to frame 5 the shapes stays where it is and everything works.

[vivapower]

well, this explain a lot of things...

[dot]

check it out project setting size, when ever u take any node like bezier,constant, checker, they default size comes with the project setting, may be this may work out

[dot]

next time make sure post it in the NUKE from The Foundry forum, rather than putting it in the nuke tut

[masky007]

And that is a badass roto reel....I need to make one of those....although the idea of rotoing individual hairs, gives me the shivers!

what about using color correction techniques for the hair and getting the matte from it to use it later as a mask instead manually masking everything - later on with little more tweaking the mask you get pretty good results

[Andreas.Jablonka]

[moved to nuke forum]

[vfxbalaji]

Hi,

Dont apply the tracker directly to roto, there is two options to apply

1. keep the roto in to layer, and apply the tracker to the layer
2.or just keep the tracker to downstream of the roto