XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Twinkle stars on revealing text with alpha

07-06-2009, 11:20 AM
Hi, anyone with a hint on how to produce twinkling stars that follow the shape of a revealing title, while preserving transparency of the comp?
Certain effects just create a a black background, which is not usable.
The title layer will be imported into a NLE TL so alpha channel is needed.
Thanks in advance,

07-06-2009, 01:37 PM
You could use particular for creating the stars, or even ae particle systems. As for following the shape of a revealling title, apply effect-> channel-> set matte and choose the title layer for 'take matte from layer'.

07-08-2009, 09:28 AM
Hi, thanks for the tip.
Tried it but could not seem to get the results.
Trouble with this is it chops off the stars that are halfway on the matte layers alpha border like a cookie cutter.
It would be nice to keep the general shape setting of the matte, leaving the whole twinkling star even if it goes beyond the alpha of the underlying layer.

07-08-2009, 06:01 PM
It would be nice to keep the general shape setting of the matte, leaving the whole twinkling star even if it goes beyond the alpha of the underlying layer.

I don't know if i got this right, but if you dont want to use the alpha of the logo, then you should be ready to render your animation.
Just make sure you export to some format that accepts alpha channel (such as Quick Time Animation or TGA/PNG sequences).

07-08-2009, 08:24 PM
I don't really quite know what you want. Do you want a trail of stars (like a comet) to reveal a logo behind them. Or do you want stars to "stick" onto the logo shape? Or do you want the logo shape to emit stars?

Is this what you want? http://www.ayatoweb.com/ae_tips_e/ae51_e.html

Here are a few more:

If you want the stars to "Stick" you need to apply the bounce setting and tell particular that the logo is the floor or wall.

07-09-2009, 12:01 PM
The text is revealed along with a swarm of star particles.
On the already revealed text, some twinkle stars that go on and off, at various positions near the edge of the text are needed.
Some samples of the effect without the twinkles but with a transparent BG (comp bg set to dark blue to see fx easier):

Once I use the twinkle stars on top I loose comp transparency with a black bg:
What is needed is the fx to produce an alpha of its own, that follows the shape of the particle but not block the whole comp.

07-20-2009, 02:15 PM
I think that can be accomplished with pre-compose and then using Track-Matte with Luminosity.

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