Slices and transparancy

[resolumeuer1962]

Hi friends, I need help and maybe what I want to do is not possible in that way, I want it to do. But here is the Basic Setup:

With Adobe After Effects I made a movieclip within different contentfields, containing different movieclips. It is a movieclip with movieclips insde, I think, you know what I mean. On the left side in the clip, I have 4 parts with wedding rings, two different fireworks and a fotostrip with different pics of the live from the future couple till the weddingday.

On the right site of the clip I placed different movieclips with different colourblocks, a flying red ribbon, a golden fluttering curtain and so on.

The wedding cake I have to map, has 4 "floors".

For this, I did the following things, now:

1. From the right clips I took the part with a flying red ribbon, that should fly and wiggle over the wedding cake. For this, I made a slice from that part and in the output transformation window, I created the shape of the slice and placed it in that way, that the ribbon fits on the cake during flying and wiggeling.

2. Then I made a second slice to use a red block from the clip and in the transformation window, I formed the shape of the wedding cake, that the red color only illuminated the cake and not the space around and out of the cake.

3. After that, one floor after another should change the color from red to different colored blocks. Again by creating slices from the partfields of the movieclip.

And so on.....

And here is the problem: In this case, the first slice (the slice with the flying ribbon) covers the cakeshaped second slice, that should fade the cake from white to red. It should look like the ribbon paints the cake to the red color. But in fact of the circumstance, that the background and space where the ribbon flies, is black like the whole background of the clip, the ribbonslice covers also the the colorfading cakeshape. So the red color can only be seen, as the ribbon slice is switched off.

And now the questions:

Is there a possibility to give the slice with the red ribbon an Alphachannel, that the black part of the ribbonslice will become transparant?

Or do I have to make an extra movie of the red ribbon with an Alphachannel, that I can do this effect?

Or is it possible, just to copy the clip on a second layer and then (with an effect from Resoume Arena 4) to key out the black color of the clip in the second layer, so that the red ribbon and the colorfading of the cakeshape could be seen together? And if so, which effect I could use, because I could bot find a possibility to key out a color directly with a pipette or something like this.

Thanks for help.

[Zoltán]

the fastest way is to use the automask effect on your ribbon clip.

the best way is to render your ribbon with alpha channel.

alternatively you could try to change the ribbon layers' blend mode to add, or screen and adjust the layer transparency.