Audio Glitches
Clouds
Member Posts: 1,599
The audio in GameSalad seems to have a few little idiosyncraticies I've come across which can be a little annoying. A lot of them you can get around - some of them you can't (or at least I have not worked out a way as yet).
For example when interpolating audio to fade a piece of music up - the music jumps up in volume at the end of the fade . . . So let's imagine you are interpolating 'Music' volume from 0 to 1 (sound off to full volume) you'd expect it to go:
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0
But it actually goes something like this:
0 1 2 3 4 5 6 7 0 0 0 0 0 0 0
ie: after 7 in our sequence it just jumps up to full volume, which sounds a bit crap to be honest and ruins a nice subtle fade-in, here is the waveform of a sine wave stuck through game salad with it's volume interpolating from 0. - I recorded it back out into Logic Audio to check what was going on, you can clearly see where the volume leaps up (and you can certainly hear it too!) - the problem is much worse when interpolating to values below 1 (eg: interpolating from 0 to 0.5 is much worse than interpolating from 0 to 2):
For example when interpolating audio to fade a piece of music up - the music jumps up in volume at the end of the fade . . . So let's imagine you are interpolating 'Music' volume from 0 to 1 (sound off to full volume) you'd expect it to go:
0 1 2 3 4 5 6 7 8 9 0 0 0 0 0
But it actually goes something like this:
0 1 2 3 4 5 6 7 0 0 0 0 0 0 0
ie: after 7 in our sequence it just jumps up to full volume, which sounds a bit crap to be honest and ruins a nice subtle fade-in, here is the waveform of a sine wave stuck through game salad with it's volume interpolating from 0. - I recorded it back out into Logic Audio to check what was going on, you can clearly see where the volume leaps up (and you can certainly hear it too!) - the problem is much worse when interpolating to values below 1 (eg: interpolating from 0 to 0.5 is much worse than interpolating from 0 to 2):
Comments
http://imageshack.us/f/844/screenshot20111226at165.png
So . . . . it's most probably something to do with the interpolation algorithm rather than audio per sa.
Interpolating the position of an actor (for instance across the width of an iPad screen) doesn't seem to display the same problem.
For the alpha channel interpolation issue you can get around the 'lumpy' fade by making your target alpha channel value higher than 1, putting in 1.2 gives me a smooth fade up, although you might have to play around with various values depending on your project , the same deal with audio fades not being smooth, try fading to values higher than 1**, it seems to mitigate the worst of the issue.
** You might have to go back to your original source audio file and attenuate it so when fading to higher values it doesn't get too loud in Gamesalad,
Interpolating from -0.2 to 1.2 gives you a smooth fade in.
Interpolating from 1.2 to -0.2 gives you a smooth fade out.
Interpolating from 0 to 1 gives you a fade in with noticeable steps/glitches.
Interpolating from 1 to 0 gives you a fade out with noticeable steps/glitches.
Hi Tynan, hey, what a great workaround. The interpolate fade in of alpha has always been particularly annoying to me, something which never seems to get fixed (at least not in the last 3 GSC updates). it used to work perfectly at one time).
Anyhow, excellent and thanks!
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