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frame disappearing act

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Michael Baxterframe disappearing act
by on May 17, 2011 at 12:37:25 am

I am experiencing an unusual layer issue when I create a test (or final) render from AE CS4. I have one or two frames in the render that have a layer disappearing. It seems to happen in the same place in the animation each time. Before the restart the glitch was showing up in a few more places, but now happens in two back-to-back frames.

I have a fractal noise layer being used twice that have layer effects (Overlay and Linear Dodge). They both have track mattes created by a pre-comp containing a 3D layer with Invigorator 3D text. This appears to be the layer that disappears. There are only 2 3D layers in this comp, but they are at least 100 z-pixels behind everything else.

There is a Particular effect on a couple of layers in the comp as well on top of the layers in question.

I have a pre-comp with a animation preset applied (RoadTrip2 with Wiggly selection set to 0)

There is no camera move in the animation.

The layers appear fine in the preview window and RAM preview. The layer order looks good.

I am using CS4 32-bit PC on a i7 960 with 6GB RAM and an ATI Radeon x800xl 512MB graphics card. I am rendering a 720p 14 second video clip (no open GL rendering) H.264 QuickTime movie (no alpha).

Any thoughts on what might be happening? I have tried everything I could think of. I am going to try turning off some of the layers to try to isolate the problem child.

Any help or suggestions are greatly appreciated.

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Tudor "Ted" JelescuRe: frame disappearing act
by on May 17, 2011 at 6:53:27 am

"There are only 2 3D layers in this comp, but they are at least 100 z-pixels behind everything else."
If there are only 2 3D layers, then how can they be 100 z-pixels behind 2d layers? Maybe you meant to say that there's 100 pixels between the 2 3d layers... or are there any other 3d layers?
Anyway, make sure that there's no 2d layers in between the 3d layers in the layer stack- that tends to mess things up.
Also, layer styles on 3d layers have a tendency to mess things up (Overlay and Linear dodge are transfer modes).
Are the 2 3D layers in the same position in z space? If so make sure that they're a few pixels apart.
Can't think of anything else right now. If the above do not help, post a screen shot of your timeline.

Tudor "Ted" Jelescu
Senior VFX Artist

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Michael BaxterRe: frame disappearing act
by on May 17, 2011 at 2:30:46 pm

Hi Ted,

Thanks for the reply. You are correct; the 3D layers are behind all the 2D layers. They are at the bottom of the stack, and they are offset to prevent any clipping weirdness.

After several RAM preview tests, I was able to isolate the problem layer. I have a 2D layer graphic that has a feathered mask applied to it for shading. The mask animates to remove the graphic and reveal the layers below it. I turned this layer into a 3D layer and the disappearing graphic problem disappeared in the latest render. Not sure why this worked, but it did. I may try moving mask layer into a separate comp and see if that makes a difference (I hate no knowing why a fix worked).

Solved the problem for now. Thanks again for the advice.


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