Transition with colored border

Hi,
I know how to make transitions with Motion.
I want to add a border to my transition.
White and black for the transition as usual but then how do I add a colored border?
For example:
I am using a brush texture. I want the border in the transition to be black or another color so we see the black border moving along with the transition.
In this example:
White is clip 1
Black expanding is clip 2
I just added the red so you see what I want in the final clip.
A red border moving out as clip 2 is revealed.

Hope this is clear. Thanks.

I'd use the black part of the circle as an Image Mask for Clip B, I think. I've actually done this some time back.. Don't remember off the top of my head what I did, but it was fairly easy. But I'm sure someone else can post a solution quicker.

One of the many options… (a bit different than Ben's solution):



A Transition project (from M5's selection of New Projects), the top/green track has a Circle Mask; mask size has two keyframes: 0% and 700%.

On another layer: a circle, with some Shape as 'design'… Geometry is keyframed analogue to the mask…

In a perfect world, both diameters are 'linked', Shape is 'published' to allow options, etc etc etc....

Thanks to both.
I will fiddle around with all this and keep you posted on final render.

I ended up doing the border frame by frame using the transition as a template.
I open my photo app and draw the line with texture as I want it.
I then export only that colored border layer as a PNG.
Import it into FCX and apply key to background color.

That way I can precisely follow the line of the transition.
I can after change opacity or add an effect on top if I want to.

i am an animator so I like that control I have over the lline !

Albo wrote: I ended up doing the border frame by frame …
i am an animator so I like that control I have over the lline !

okayyy … <puzzled> but when it gives the wanted results …

but:

Albo wrote: … my photo app and draw the line … I then export only that colored border layer as a PNG. … Import it into FCX and apply key to background color.
…

… what bg color, you're telling us, you export only the drawing layer ? when your drawing is done on a transparent background, there's no need to 'key' anything, FCPX handles the alpha in a PNG…

Yes I know that the PNG has a transparent backgroung.
I ended up importing my PNG as a sequence in QT Pro. They did have a ttansparent background.
Exported the sequence and for some reason when I put them on the timeline there was a black background.

That's why I keyed them. It worked.

Just wondering what you are "puzzled" about? Maybe my explanation wasn't clear.

Albo wrote: …Just wondering what you are "puzzled" about? Maybe my explanation wasn't clear.

… nono, …missed that detour through QTpro… when you export from there, you have to choose a codec, which supports transparencies, as proRes4444… = no keying necessary …

No, was just puzzled .… or say surprised by your workflow… a frame-by-frame 'drawn' animation for a - in my imagination - simple transition. E.g. why not drawing or, at last, importing your drawings into Motion? You'd save all that back'n forth in several apps…
Anyhow.

…all fine…

Oh! That's it. I didn't noticed that my codec had changed. Didn't event think to look there.
I have been working on another project and the setting was different.
Always the simple things to check!

Thanks.

Thanks for your help, this was useful !