Moho Forum

I want to reduce the opacity of a shape over time, simulating dawn. I tried doing this by setting the alpha of the shape to 255 at frame 0 and at 0 at frame 72. The exported quicktime doesn't show a nice transition but a transition with a lot of flickering (I hope I use to correct english word here). Is there a better and nicer way to what I want to do?

Gr,
Frank

Export to a sequence of PNG images and then composite it with a video editor.
I cannot test your problem because in linux there is no mov or avi export but I can say that there is not flickering when using image sequence.
I suppose it is due to the compression of the movie.
Genete

Need to see the "flickering" to know what is causing it. I use alpha to fade all the time with no flickering.

My guess is compression as well but I'm not 100% sure.

-vern

Why fiddle with the alpha setting in the separate shapes? I just did a test with some character of mine and used the opacity setting of the bone layer. Worked nicely in MPEG-4, smooth fade. The only drawbacks I saw:

- keyframes for opacity settings of layers only show up in the timeline if you activate that option in the timeline settings.
- you will not see any fade in the work area, only in the rendered image.

One possible reason for using shape alpha is that you'd have 255 levels of opacity to tween between, whereas with layer opacity you only have 100 levels (since it uses percent, and neither allow decimals). The effect would still be less smooth than doing it in a compositing program either way, though, if you're trying to do a very slow, gradual dissolve.

I beg to differ. It doesn't make a difference wether the two extremes "visible" and "invisible" are marked with "100% / 0%" or "255 / 0" if you want to make a complete fade out / in - the program internally inbetweens the fade with as much accuracy as needed. Most fades occur in durations shorter than 100 frames anyway.

It would make a difference if the program internally cannot use smaller increments than 1. And, btw, our eyes cannot distinguish between a character with 80% visibility and one with an alpha setting of 201 - even in a direct A to B comparison it is hard to spot opacity differences as small as 5%.

I don't see the need for another compositing program here, except hat AfterFX gives me finer and more direct control of all parameters.

I'm sorry if I relayed incorrect information. It was my assumption it worked the same way that the layer shadow or layer blur works, which seem to have noticeable increments of that sort.

No need to apologize. I didn't say the output could not flicker - if you saw flickering output, then there's some bug inside. I just said that the unit and numbering system chosen to indicate the amount of transparency (or blur or whatever) doesn't make a difference as long as the software internally calculates with adequate accuracy.

Thank you all for the help. Reducing the opacity at the level of the layer seems to help a little. Nevertheless I decided to reduce opacitya later in the process using a video editor.

Gr,
Frank