OpenGL

[Todd Kopriva]

from “Render with OpenGL”:

“OpenGL is a set of standards for high-performance processing of 2D and 3D graphics on the graphics processing unit (GPU) for a wide variety of applications. For After Effects users, OpenGL provides fast, high-quality rendering for previews and final output by moving rendering from the CPU to the GPU on the display card. Sometimes, performance improvements due to processing on the GPU are referred to as hardware acceleration.”

So, basically OpenGL to the After Effects user is a way to get faster rendering. But the OpenGL isn’t entirely accurate, so it’s really just good for rendering previews. I leave it in OpenGL—Interactive mode, so that it speeds up rendering when I’m dragging things around, but I still ge the full-fidelity rendering that doesn’t use OpenGL when I’m not dragging things around.

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Todd Kopriva, Adobe Systems Incorporated
putting the ‘T’ back in ‘RTFM’ : After Effects Help on the Web
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[Kevin Camp]

you can check wikipedia for a complete definition, but opengl is basically an open source programming language that allows access to the gpu (graphics processing unit) on your graphics card for fast computation of supported opengl effects.

in ae, there are some effects and other features (like motion blur, blending modes and 3d) that can be accelerated by opengl.

there are, however, several negatives of opengl in ae:

1. opengl does not render quite the same as ae’s software render engine (opengl previews may look different than renders) and it doesn’t seem to handle mismatched pixel aspect ratios too well (footage/images that don’ match the comp’s par often look jaggy).
2. it is not compatible with ae’s multiprocessing, and will disable multiprocessing for previews if opengl is set to ‘always on’.
3. it can lead to instability within ae, though i’ve seen this get less and less with later versions of ae.

the first two issues can be overcome by setting previews to use opengl only for ‘interactions’, meaning only as you drag layers, settings or scrub the timeline. although with opengl interaction only enabled, you may not see some of the non-opengl accelerated effects as you scrub, but you’ll see them when you release the time cursor.

many users work with opengl off completely and i don’t think i’d recommend working with opengl on for anything other than ‘interactive’ for previews.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Kevin Camp]

todd is a faster typer than i…

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[Todd Kopriva]

Heh. Jinx. It looks like Kevin and I mostly agree. 😉

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Todd Kopriva, Adobe Systems Incorporated
putting the ‘T’ back in ‘RTFM’ : After Effects Help on the Web
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[Kevin Camp]

wow, two sets of responses posted within seconds of each other… pretty impressive.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[David Bogie]

.. a cruel joke, especially in your AE machine is a Macintosh.

bogiesan

[Sam Young]

openGL is a big piece of crap. if anything causes AE to crash, openGL is usually the culprit. in the long run, in the interest of time not wasted, you’re better off just leaving it turned off.

[Adolfo Rozenfeld]

It’s all really tied to configuration, Sam. And more specifically, to the display card/driver combo.
So, if you do get constant crashes because of it, by all means turn it off.
It’s also fair to say that I could use the fingers of my hands to count the number of OpenGL-related crashes I experienced in the last couple of years. And I think that anyone using a known, reliable graphics card/driver combo (not necessarily the latest and greatest) could say the same thing.
FWIW, I always use OpenGL – Interactive, as described by Todd.

Adolfo Rozenfeld · Adobe