Twixtor in FCP (masking & tracking?)

Hi there,

I have been experimenting with twixtor to create super slow mo for some action/sports clips, so far my best results are to with 60p conf -> 24p footage shoot at a high shutter speed against a fairly plain background (eg: person jumping - background blue sky only)

However I still get the occasional unwanted blurring/distortion that I just can't seem to get rid of, I've seen some amazing examples of twixtor that don't have these problems.

this leads me to think these clips use twixtors masking and tracking functions to help it keep things looking good.

I have no idea where to start with these functions, I've looked online for tutorials etc with no luck.

I'm using twixtor pro in FCP, hope someone can give me some tips or point me in the right direction.
Mike.

yes im shooting a 60fps and conformingto 24/25 with cinema tools, also shooting with higher shutter speeds to make the images sharper which seems to help twixtor.

I am getting some pretty good results but still have unwanted artifacts appearing.

I can't think of any other way to reduce this!

I have read the manual but it's not making much sence. I know how to make a very basic matte/mask in fcp. But how do i make a mask that follows my subject in the foreground that i want to be clear and in twixtor slow mo? and how do I tell twixtor to use that mask!?

here is a link to one of my tests,
http://www.appendixj.org.au/twixtortest-720HD.mov

the main problem can be seen in the camera right hand, and slightly in the other hand.

So do I need to make a tracked mask/matte in something like after effects and import the peices of footage wih transpartent backgrounds into fcp? I still don't understand how how to to tell twixtor to use these masks, and what actualy needs to be masked in the first place.

After I wrote that I remembered there is a couple of examples here:
http://help.revisionfx.com/tutorial/49/

Here's a quick example using your footage:

1) Output with no layer
http://www.revisioneffects.com/bugreports/results/outputNoLayer.jpg

You obviously end up with some misregistered fingers

2) Output with layer
http://www.revisioneffects.com/bugreports/results/output.jpg

I did a quick matte (looks like below) - could be tighter (right now in Twixtor I set Inv Matte Shrink to 4 as this is a sunday afternoon roto job :) -- you need to do that on the original footage without twixtor - but look first where Twixtor breaks and this will tell you what source time frames you need a matte where.

3) Matted Foreground looks like this, we use the Alpha channel here
http://www.revisioneffects.com/bugreports/results/mattedLayer.jpg
To use such matte in FCP to separate foreground from backgound, you first need to make an animated matte (black and white footage... Where white are pixels of the foreground element), and then drop it into the FG Mask clipwell of Twixtor.

4) Also note: The footage seems to be shot with some nasty auto-sharpness or something - look at the dark blue fringe - and the ghosting around everything - that absolutely does not help
http://www.revisioneffects.com/bugreports/results/Untitled.jpg