track matte question

i have a nice looking track matte and haven't been able to figure out how to dissolve into and out of it. the matte is a simple light to dark gradient. i have it on a middle track, say track 2. the image that goes into the light area is above the matte on track 3. the image that goes into the dark area is on track 1. this is all working fine. the track 3 image is set to composite mode 'track matte luma'. these are all b&w images. as i say, this is all looking fine. problem is, once i select the composite mode, dissolves don't work. neither does opacity. fcp v6.0.6.

how to i dissolve into and out of this scenario?
how should i set things up differently to be able to achieve this effect?

thanks,
BabaG

Try nesting it, then apply the dissolve.



www.strypesinpost.com

thanks strypes. i was hoping to avoid a nest as the sequence is very complex and having to bounce around between nests and the assembly sequence will complicate things a lot. i assumed a nest would work but was hoping to find another way. couldn't get luma key filter to do it either.

thanks again,
BabaG

Does it work when you keyframe the opacity?



www.strypesinpost.com

no

using the chroma keyer allows for a dissolve to be applied to the matte but now i can't figure out how to get image into both sides of the matte. what i've got so far is track 3 for the matte with the chroma keyer and (using the visual controls for the keyer) chroma and saturation unchecked (the images are b&w). track 2 for one side of the matte. track 1 for the other side of the matte. all composite modes are set to normal.

this setup allows for a dissolve to be applied to the matte (and presumably the images as well). the problem is that both images are being applied to the same side of the matte rather than opposite sides, as in one image for the black side, one for the white side.

anybody got any tips on how this might be made to work without losing my dissolvability?

thanks,
BabaG

Have you tried putting the shots on either side on a track above your effect then dissolving them to/from the empty space?

Can you export that section as a stand alone movie and re-import it to use as a single unit? When you dissolve, of course your blacks and whites are not pure during the dissolve period, so the results get muddy. If you make it standalone and then apply dissolves, the effect is not affected.

this works going from matted material to full frame material and back. the problem arises when i have to transition to another matted image from a matted image: no dissolve capability. thanks for the idea, though. it does work for the beginning and end of the sequence.

You could build in handles on your originals before exporting so you have room for dissolves when you reimport. Actually, given there is a gradient already, what happens if you add a gradient dissolve instead of a cross dissolve and add the same gradient to the well of the transition. No clue if that will work, just an idea.

what i've been doing is this as it allows me to have my three (for now) picture tracks and keep them editable.

i've been exporting a still of each element of the sequence and using that to create a matte roto'ed around the relevant subject area. these mattes replace the gradient. i put my main plate bg on track 5 and the other picture elements on tracks 1 and 3.

i created a duplicate sequence with the temp edit of the elements to be matted into the plate. i then synced the drawn mattes into that sequence. there are more than one element playing simultaneously over the plate so i actually have two tracks of foreground elements with accompanying synced mattes.

after syncing the mattes, i duplicated the dissolves that are on the picture elements and put them in the mattes. that gives me mattes that dissolve from one to another in sync with the picture dissolves. i then exported two copies of the mattes, one for the single elements and another combo matte that has both foreground elements built into it.

i put the combo matte on track 4 of my original sequence. using travel matte luma composite mode on the plate in track 5 gives me an image of the plate with one fg element, from track 3, blended into it and a black area where the second element goes. putting the remaining matte element on track 2 and its accompanying picture on track 1 allows the track 3 elements to also be set to travel matte luma and fills in the remaining matted area.

the workflow is mechanical and labor intensive but does allow for the picture elements to be worked with with a bit of flexibility. the picture elements have dissolve effects that can be varied. the matte tracks have dissolves that are built in, precomped. if an element needs to be extended, the matte can have a freeze added. if dissolve lengths need to be changed the mattes need to be remade but i think i can get through a lot this way as a lot of what's being done involves more moving and juxtaposing elements rather than changing the dissolves.

the reason i didn't want to nest is that the plate is a sync scene and with all of the elements moving around against it i would have needed to pull the plate in in pieces with the various elements nested against it. going back and forth in that manner seemed an invitation for sync issues and mistakes. this way i can fairly freely move pieces around and keep the plate in one piece. makes for a lot of stills, mattes, etc. but it does seem to work.

in a nutshell:

trk 5 - bg plate in travel matte luma mode
trk 4 - combo matte with two fg areas blacked out and built in dissolves
trk 3 - fg elements also in travel matte luma mode
trk 2 - individual mattes for remaining fg elements
trk 1 - remaining fg elements in normal mode

of course, none of this would be needed if travel matte luma didn't kill opacity settings and transitions.

anyway, thanks for the suggestions and i'd love to hear what else i could try that might be simpler.
BabaG