Hi I don’t know if this information will be useful. I’m new to this issue in Blender so if anyone has a better workflow or some suggestions on how to improve any of this, or if I’ve got any of it wrong please let me know.
I’m an experienced 3D / compositing artist in other software and migrated to Blender about six months ago. An example of previous work I’ve done is here: https://www.youtube.com/watch?v=JZtXz_2groY
Blender’s node editor (compositor) is amazing on many different levels, however it apparently doesn’t have Ram Caching abilities. So for me this was a problem because the work I do in compositing requires looking at Comps moving and not static. So for this reason on my current project I’ve been generating elements in Blender and exporting them via multilayer EXR to After Effects. This works in a basic way except there are some technical issues with Multilayer EXR export workflow to After Effects and it’s quite tedious to go through all the extraction hurdles 32 bit multi layer EXR’s involve.
So I was getting really frustrated with it till I came across this brilliant tutorial by Eric Toven which I really recommend anyone having this same set of frustrations to watch. To me, this knowledge should be effectively be Blender 101 but for a user new to Blender or learning Blender this render pass workflow (which is simple and straightforward once you know it) is actually difficult to find. Being able to render out passes to other compositing software in any file format needed is essential.
Eric Toven
Blender 2.55 and render passes.
It’s basically how you can render out combined passes (like Mulitlayer EXR or RPF) in any format JPG, Tiff, PNG, TGA etc. If anyone has any other video tutorials on this issue please feel free to post them as well. I’m sure other people probably covered it, I just found this to be the tutorial that really addressed the problem for me.
Following this I also then came across this python script by Tamir Lousky called “save_all_renderlayers_and_passes” which you can see in operation and download from author’s youtube page which automates a lot of the steps involved.
https://www.youtube.com/watch?v=6lzzfEdxQik Although currently I haven’t managed to get it working in Blender yet.
These are my notes on why I personally found open Multilayer EXR to be difficult to implement in a real world production pipeline. I fully understand that EXR’s are amazing qualilty and are the format of the future, and they do also have the advantage of being one file instead of many (Rich Pixel Format aka RPF from Max does the same combining) so I’m not trying to denigrate EXR’s or the use of them in any way. I just personally found them to be difficult to implement, time consuming and system taxing.
Problems with EXR to After Effects Workflow:
- Multilayer EXR combined passes (beauty passes) come into AE very muted with the color levels subdued and you have to use a Color Profile Converter effect in after effects to get them to appear correct. It’s almost impossible to know that that’s what you have to do, I only found out that noticing it in one part of this tutorial by AE Tutor’s channel.
AE Tutor
Render Multi Pass EXR’s in Blender and Extract EXR data in After Effects.
- Z-passes come into AE white because of their extreme value range - and there is no Normalize node in AE. So Zpasses (Depth Passes) need to be Normalized in Blender first. To be fair to EXR this is a problem whether EXR, PNG etc, however the principle of Multilayer EXR should be it all works in the one file, so there’s only one file to render. That’s how RPF works. So in terms of the issues with Depth passes - There is a great Blender Cookie tutorial by Bartek Skorupa on the need to Normalize Z-passes (Depth matte) and also on how to set up a depth material manually that looks and works much better than the Blender default with no jaggies and poorly anti-aliased matte edges.
Bartek Skorupa
Creating Mist in Blender and Cycles with ZDepth
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To implement Multilayer EXR in After Effects unless you are using Fnord Pro EXR in AE (http://www.fnordware.com/ProEXR/) then you have to use the inbuilt Extractor effect in After Effect’s 3D channel effects panel and getting the Extractor process to work on a Multilayer EXR with many passes is a ton of work, and is non creative and painful.
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Multilayer EXR’s in AE are really taxing on the system.
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Rendering in EXR means you have to composite in AE in 32 bits which takes away a lot of useful effects in AE. EXR’s are technically better but TGA or Tiff or PNG are pristine image quality and even Photo JPG renders at 100% settings are good enough for many composite scenes where you want the compositor to actually perform well on RAM previews. If you watch any Andrew Kramer AE tutorials he basically renders at Photo JPG lossless (JPG 75% quality or above) because the quality is still fine for his needs but the file sizes are much smaller.
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Not a specific EXR problem however there’s no Matte Shadow Material (shadowcatcher) in Blender Cycles as in Max. The workflow in Blender for rendering such a simple thing as a shadowpass is very complex and counter-intuitive. It should be one button you press. i.e tick the button that says “shadow pass”. Instead it becomes a process of setting up multiple different render layers and tweaking settings in the compositor. This wastes a lot of time for what should be one button and restricts the creative process.
Anyhow, sorry about the long post and experienced Blender users may well be rolling their eyes, however as a relative newbie, just such a basic thing as being able to go to bed at night leaving my computer rendering multiple passes (beauty pass, depth pass, ao pass, shadow pass, normal pass, mist pass) etc in formats that aren’t EXR took a long time to know what to do. If anyone has better solutions or a better workflow to this please post it or let me know.
I hope these notes and collection of specific linked tutorials helps anyone else avoid spending time trying to work this out, because it’s a big time waster when you are trying to work between Blender and AE.