Linear 32 Bit Workflow Setup

After Effects: Grading

Info

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The following videos show how to setup a After Effects comp, 32 bit Linear color with Layered exrs, an Ambient Occlusion pass and an RGB Matte. This should get most 3d artists up and running in AE.

To Set The Frame Rate

Set Global File Import Preferences for Frame Rate
After Effects > Preferences > Import (sequence footage) I use 24fps (film)

To set the Base Frame Rate go to File > Project Settings, and change the timecode base to 24fps or your desired frame rate.

Check image sequences are correct
Check individual file framerates = rightclick on file > Interpret Footage > Main

Check compositions are correct
Composition Settings = apple k (not sure on PC) or right click on composition in Project Tab.

Video 1.1: Setting 32 Bit Linear Color Mixing (3:45 mins)
 

Video Notes

Click the number at the bottom of the project tab. By default it’s 8 bpc. This will open up the Project Settings.

Change Color Settings > Depth: to 32 bits per channel

Check on Blend Colors Using 1.0 Gamma

Video 1.2: Setting Up Ambient Occlusion (AO) (0:38 mins)
 

Video Notes

In the comp, set the ambient occlusion layer’s mode to “multiply”

If we can’t see the mode, toggle the “Toggle Switches / Modes” Button.

We can also grade the AO pass with levels or curves for different effects.

AO is usually too strong so we can tone down it’s opacity by pressing “t” to bring up the opacity options for that layer.

 
 

Video 1.3: Using Layered EXRs in After Effects (5:06 mins)
 

Video Notes

To manage layered EXRs we use the

Pro EXR Plugin, you can download it here. Although it says it has a 15 day trial it seems to works fine for longer than 15 days.

Install the plugin by dragging the files it into your After Effects Plugins folder.

On a mac it’s found…
Macintosh HD/Applications/Adobe After Effects XX/Plugins/Format

Restart After Effects and in the file menu you should see

File > Create Pro EXR Layer Comps

Select your layered EXR and run that menu item.

This will create a whole list of Comps based on the names of your layers. Without the plugin we can create these manually using the “Extractor” effect which comes with After Effects, but this is much easier.

By defualt the RGB layer is usually set correctly to Linear Color but the other layers may still be set to sRGB gamma.

To fix gamma on the new layers create a new effect called…

Color Profile Converter

Effect > Utility > Color Profile Converter

Once the effect is on your layer, simply check the

Linearize Input Profile checkbox

to correct the gamma on these layers.

Video 1.4: Using RGB Mattes to break up the scene (4:38 mins)
 

Video Notes

In After Effects we can combine up to 4 mattes in the one image by using the R G B and Alpha channels of our 3d render. In other packages we can have many more mattes, unfortunately in AE we are restricted to 4. To create more we need more mattes.

1. Create a composition with the layer you wish to mask
2. Add the RGBA mask to another layer, hide it so it’s not visible
3. Select the layer you wish to mask
4. Go Effect > Channel > Set Matte
5 In the Set Matte Effects settings on the layer set the mask layer to your RGBA layer and set the channel to be the colour you wish either Red, Green, Blue or Alpha.
6. Your Layer should be masked now, check the matte settings to make sure there’s no halo effect around the masked area. You can play with the matte settinsg by right clicking on the original file and going
right click > Interpret Footage > Main or alt + command + g

 
 

Video 1.5: After Some Grading (0:01 mins)
 

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