Using 3D Z-Depth to color correct in After Effects
by Dylan Usic
on
Jun 24, 2008 at 5:48:50 am
Hi,
Does anybody know if there is a way to use Z-Depth information that you have rendered in a 3D program to color correct a 3D animation (e.g. making distant objects green and making closer objects red with a smooth gradient in between)? So your basically replacing the z-depth colours different colours but I still want to see the textures and objects of the original 3D animation.
Re: Using 3D Z-Depth to color correct in After Effects by Kevin Camp on Jun 24, 2008 at 12:07:09 pm
you might try an effect like colorama or a gradient overlay layer style to the depth matte to colorize it. then place it over the other layers and set it to use a blending mode like color or hue (or maybe others) and the opacity to get the look you want.
Re: Using 3D Z-Depth to color correct in After Effects by Ron Coy on Jun 24, 2008 at 2:08:47 pm
sounds like a job for expressions.
Though, I don't know how you would get the z info to color a 2D layer in varying z space... I'm trying to wrap my head around just the concept, I know nothing about writing expressions myself, but I can usually figure out what needs to relate to what in these situations. I just can't figure out how you could make something further from the camera a different gradiated color from something in the foreground, without some kind of 3D aware plugin or camera effect.
Re: Using 3D Z-Depth to color correct in After Effects by Brett Lewis on Jun 24, 2008 at 10:45:22 pm
I think that you might be trying to create varying colour haze using a depth channel.
There is a plugin in after effects, I think its CC ramp or something that allows you to change black and white into a spectrum of colours. I would apply this to the Depth channel, then load a duplicate of the depth channel as a luma matte for the rendered image. this way the depth should be coloured. To fade the power of it you might want to duplicate the RGB as the bottom plate and fade the opacity of the depth CC ramp layer.
Re: Using 3D Z-Depth to color correct in After Effects by Darby Edelen on Jun 28, 2008 at 8:19:44 am
[Kevin Camp]"you might try an effect like colorama or a gradient overlay layer style to the depth matte to colorize it. then place it over the other layers and set it to use a blending mode like color or hue (or maybe others) and the opacity to get the look you want."
I was going to suggest something very similar. I was going to say that you should use Color Correction > Tint to map your black and white to different colors (if you need a different color for grays try Color Correction > Tritone).
From there you could use the Color, Hue or Multiply blend modes depending on how you want to affect your footage... Color and Hue would preserve whites, where as multiply would cause the whites to take on the color they are being multiplied with. Multiply behaves a lot like an lens filter would on a real camera.
If you want to be able to adjust the way that the colors are mapped to different depths you can apply a Color Correction > Curves or Levels effect before the Tint/Tritone effect to change the distribution of blacks/whites/grays.
Also, be sure you render your depth information in 32bpc and work in 32bpc in AE if you want to maintain the utmost accuracy.
Darby Edelen Lead Designer Left Coast Digital Santa Cruz, CA
Re: Using 3D Z-Depth to color correct in After Effects by Dylan Usic on Jun 28, 2008 at 8:59:45 am
This method sounds good. Maybe I should clarify exaclty what I am trying to do, I am creating a short film (3D animation) and I will be creating a 2 disc DVD. The first will be a normal viewing mode and the second disc will be a 3D viewing mode which can be viewed with ChromaDepth 3D glasses. With chromadepth closer objects must be red, further ones blue or black and the rest in between according to the order of colours in the rainbow. I was hoping to utilise the Z-Depth information with my 3D animations to achieve this look (so closer objects are red and further ones are dark blue) so I'll see how it goes.
