xfade and uneven output from line

jemfiner's icon

I am trying to use Jitter to animate still images (1536 x 1024 pixels) by crossfading from one to another using xfade. The patch enclosed is what I am using to send values to xfade.

This all works in theory but I am finding that the values output from line are unpredictable. sometimes it runs smoothly from 0.0 to 1.0 and back again, sometimes it sticks and then picks up a bit later.

I've had a look at scheduling prefs and reduced scheduler slop to 1ms, overdrive is off. My mac is 2.5 Ghz, with 3 GB RAM.

Max Patch
Copy patch and select New From Clipboard in Max.

Is it simply a case that my computer is not powerful enough to crossfade images of this size smoothly, or are there ways (I hope so !) that I can optimise MaxMSP to give a consistent smooth ramp of values from line, and hence a beautiful smooth crossfade ?

Thanks very much,

Jem

antialias's icon

Have a look at Recipe 31 (Animator)-- there's a technique for using cpuclock to drive animations smoothly.

jemfiner's icon

That looks promising, thanks for pointing me in its direction.

Jem

jemfiner's icon

If one has to use metro to trigger cpuclock, is one then not back in the vagaries of timing that using cpuclock is trying to avoid ?

Thanks

Jem

Rob Ramirez's icon

line generally has more reliable timing with Overdrive turned on, i believe.

also, you might want to try bline instead of line.

jemfiner's icon

Regarding overdrive, the "setting scheduler prefs" documentation advises leaving it off if you are primarily using Jitter, which I am. It seems to be better off.

I'll have a look at bline, thanks.