View Full Version : My CG footage is just too nice

06 June 2003, 03:11 PM
Hi all,

I am mixing 3d footage (a teddy bear) with real footage (a child bedroom) recorded with miniDV. I have matched lights and shadows, but one thing I would like to do is deteriorate the 3d bear, so it 'd look as if i'd recorded it with a miniDV camera, not as a perfect 3d bear.

I have tried (in After Effects) to put some noise and little mosaic tiles but with little success.

Has anyone have a method for this?

Thanks for your time

06 June 2003, 09:27 PM

I'm not sure how to do this in After Effects, but to start maybe try adjusting the saturation (lower), and add a grain or pixelize to the cg elements.

This might help improve quite a bit. Like I said, just as a starting point for you.

06 June 2003, 10:41 PM
one of the largest diferences you'll notice is that DV is 4:2:2 or even 4:1:1 color space. This is akin to mpg video compression. Right now your 3D is going to be rendered 4:4:4 or uncompressed.

What you need to do is to seperate the luma (4) and 2 chroma channels (2 or 1) of the 3d, and down rez them.

Look for a way to convert your 3D to YUV color space, and then scale the U&V to 1/2 or 1/4 rez.

Not too sure how to do it in AE.... Might require the production bundle.

06 June 2003, 09:15 AM
Thanks for your replies,

I have trying to take control over YUV channels, but AFX seems to lack the RGB>YUV color space conversion.

So I separate the RGB channels (one layer, one color) and then applied the Mosaic effect (less resolution) to two of the colors/layers, and mix them with "Add" blending mode. Then a little bit of noise to the 3rd color/layer.

It looks more "miniDV", but I think the YUV separation would be the perfect choice...


07 July 2003, 10:56 PM
I've never tried this but in theory I think it works. Try exporting your 3D to DV tape in separate passes. Then reimport it into AE. Apply your alphas and recomposite it. Good luck.

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