Multiprocessing disabled: incompatible expression or effect

[Kevin Camp]

this portion of the manual may help you find the culprit:

https://help.adobe.com/en_US/aftereffects/cs/using/WS9F936D13-E76A-41e4-BF8F-577132AB4723a.html

see the portion on ‘when after effects temporarily disables multiprocessing…’

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Darby Edelen]

In addition to those effects noted in Kevin’s link, the sampleImage() expression will disable multiprocessing.

Luckily there’s a way around that: Animation > Keyframe Assistant > Convert Expression to Keyframes. Make sure you do this as a last step just before rendering.

The only way around the issue of an effect disabling multiprocessing would be to pre-render the footage, essentially baking that effect into it. If the effect is one of several effects on the layer then it might get more complicated.

Darby Edelen

[Tom Ma]

yup. Lens Blur is the culprit, thanks!

“If a composition uses any of the following effects, the composition will not be rendered with the Render Multiple Frames Simultaneously multiprocessing feature:

Auto Color
Auto Contrast
Auto Levels
Cartoon
Lens Blur”

[Darby Edelen]

If you have some money to spare, and it’s an effect you use very often, then I highly recommend this plug-in:

https://www.frischluft.com/lenscare/index.php

It renders faster, looks better, and has more features than Lens Blur. It also doesn’t disable multiprocessing 🙂

Darby Edelen

[Tom Ma]

I have it!
nice tip, thx.

[Todd Kopriva]

The new Camera Lens Blur effect in After Effects CS5.5 also doesn’t have this shortcoming.

———————————————————————————————————
Todd Kopriva, Adobe Systems Incorporated
Technical Support for professional video software
After Effects Help & Support
Premiere Pro Help & Support
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[Tom Ma]

that is good to know. Are the other limitations also removed.
(I forget the exact effects, but there were a handful.)