So I’m still new to the whole OpenEXR format, but I like the whole concept of “All the layers in one file”. That being said, here is another struggle I found working with 32-bit OpenEXR render from Cinema 4D and imported into After Effects CS6.
#1 The edges on a transparent / alpha on render passes were looking jagged and pixelated
#2 The depth pass was pure black
First, let me show you my settings out from C4D:
OpenEXR B44 32-bit Multi-Layered file with a Straight Alpha channel. Also, I am NOT using Linear Workflow in Cinema 4D.
Now on the the fixes for the issues above:
#1 – Jaggies
There are two problems with seeing jaggies.
Part 1: When bringing in the OpenEXR files to After Effects, I had to first to re-interpret them. At first pass they are brought in as ‘Premultiplied’ alphas instead of ‘Straight’ as they were rendered out. Right click on your .exr file in the project pane and select ‘Interpret Footage->Main…’
Part 2: The jaggies are because when using the “Create ProEXR Layer Comps” it sets the UnMult (or un-multiply) option to “On” in the EXtractoR plugin. For my settings since I’m rockin’ the straight alpha, this needs to be off. You will need to preform this on any channel that has ANY level of transparency or alpha in it.
Once you change the UnMult setting (and your alpha is interpreted correctly from above), you should also see the jaggies disappear instantly. Well, not instantly if you have a 4K .exr with 20 some layers inside. It takes me about 5 seconds to process.
#2 – Depth Pass Issues
(Update 2012.7.24 – Since upgrading to 13.061, this particular issue has seemed to disappear)
Actually the depth pass isn’t screwed up as I first initially assessed. It’s very heavy towards the black side of things and with working in a 32-bit file, I’m guessing it took what C4D probably makes as an 8 Bit file and throws it into the 32-bit space. When I started working with my depth pass, it was straight black to my eyes. After creating 2 levels adjustments, I managed to get the depth layer close enough to where it should be. I would prefer an OpenEXR expert to email me the absolute math settings, but for my purposes it’s close enough. I used the first levels adjustment to get a rough mix and used the second to dial-in the subtleties of the channel that I couldn’t do without looking at a second histogram for reference. Have a look at the thumbnails below (which show the levels settings that worked for me) to see what I’m talking about.
Hopefully you were searching on “AE OpenEXR Cinema 4D Jaggies / Alpha Channel” or something along those lines and found this post. Happy compositing.