3d fog after effects

[aftereffects]

does anybody know how to use the 3d fog option in after effects because i tried using it i applied the filter in front of a black backround and made the fog white and still didnt see anything im trying to apply fog to my logo so if you can help please do thank you

 

[PsiPhi]

Try as much as you want... it won't werk for you. This stumped and frustrated me for ages until I bought that AE5.5 Magic book.
The reason for this filter (and all the 3D Channel filters) is to help you composite 3D layers rendered from Maya, 3D Max etc. that contain z-axis information to control depth perception. These files include .rla files and a couple of other formats that I can't remember right now. You can also blur along the z-plane and do some other interesting tricks (a bit of a lame explanation, I know, but I'm in werk and AE is on my machine at home so I can't check it out... sorry!!).
Anyway, see if you can download some *.rla files and then apply the 3D channel effects - prepare to be amazed!

 

[EdwardMartinIII]

I faked a layered fog effect when I couldn't quickly figure out how to get good fog. I made a 2880 x 1920 pct file in Photoshop. I made the image all white and applied the CLOUD filter to the alpha channel.

Then, I imported this image into After Effects. By applying a slightly variable squeezing and slow lateral motion and changing the layer's opacity to, say 40%, I had one layer of fog.

Using the same technique, I made about five layers, squeezing and moving each one slightly differently, but all in the same general direction (to simulate layers of moving air). Then, I passed my moving element through all the layers gradually.

The effect is this big thing looming up out of a fog. Very cool and I got to keep all the hair I would have otherwise torn out.

Cheers,


Edward

"Cut a hole in the door. Hang a flap. Criminy, why didn't I think of this earlier?!" -- inventor of the cat door

 

[PsiPhi]

Another variation of this is to use a Fractal Noise filter on a new solid or adjustment layer to impart a gently swirling effect. Add a touch of Gaussian blur to soften it up a bit and it's pretty convincing. You should also mess around with different transfer modes (although I find that Screen is best for this) to highlight the fog effect over the brighter parts of the backround and eliminate the black parts of the fractal noise.

 

[mandark1011]

does Tiff files support the z depth channel?

 

[PsiPhi]

Nope. A tiff file is an uncompressed image file format but is 2d, hence doesn't contain any z-axis information.

 

[PsiPhi]

I just remembered amout depth mattes, though. I'm using Bryce a bit at the moment and you can render a scene as a Distance Mask. This essentially renders out a black & white version of your scene where Black = near and White = far away. When you import your original footage and distance mask into AE, you can use the mask as the blur channel in the Compound Blur effect to create a really cool depth-of-field look where far away objects are blurred. This really ups the realism quotient without adding hours onto the Bryce render times. Bryce isn't the best 3d program in the world either, so this can help to add some much needed realism.

Anyway, what I'm getting at is that you could easily use a Tiff file (or any flat picture or video file format) as source material to create depth-of-field FX. I'm pretty sure you should be able to do this with any 3d program too.

I love contradicting myself.

 

[mandark1011]

thanks for the info. It always amazes me how people can come up with solutions to either software short comings or lack of knowledge. thanks again ill just re-render in RLA and then get the channel i need