multilayer .exr

I see in reading various development notes that there is a move afoot to have such a thing as a ‘multilayer .exr’ …something I had not heard of before :rolleyes:
I see it is to be available for animation as well as images…also mentioned is the fact that no other software handles it :smiley:
so my question is -
Where has this come from and where is it going?
I presume it is just a convenient container for RGBA info as a lossless format but at higher depth than PNG… this being esp useful for complex chains of compositing without noticeable degradation?
.exr files are typically BIG so how can this work for animation?and playback?storage? memory use?
Please someone enlighten me about this topic :confused:
I mention too that .exr compositing was briefly discussed by myself and others at the Indigo forum when talking about implementing light groups to provide some variable ‘exposures’ with the MTL method…does this functionality in Blender leave open the possibility of using multilayer .exr with the renderer API planned? that is can Indigo utilise this Blender stuff like Yafray passes info?
ha hope that makes sense to someone :slight_smile:

ah oooh… ok i guess I should have done a search :wink:
hmmm… well I should read up the official .exr documentation for a start then eh… :slight_smile:

ok after some reading I can answer my own questions :smiley:
some attributes I discovered -

carries more z depth ,exposure and colour depth - not necessarily at 32bit but 16bit is acceptable trade off too
doesn’t have to be RGBA indeed if another way saves 50% space
can carry other info as well and does not violate the rules of what an exr file is - compatible and portable -so blender can put in its own stuff as well
has built in on the fly compression/decomp that can be multithreaded :cool:
can store info as scanline or tiles and also carry an area outside the view for camera jitter etc
can carry layer info too <—
has built in thumbnails for fast previews
can store env maps
integrates with video cards for fast display and uses cg language to approximate full quality replay well
ties in with professional cinema use :cool: and no doubt puts blender up with top shelf players :slight_smile:

all good stuff if I interpret it correctly…:smiley:

but… it seems to need pretty fast hardware to view full HD size - probably needing RAID0 and a high end quadro to attain 24-30fps… how this fits in with the average blender user I am not sure :rolleyes: perhaps for 50% HD it is ok…
So it seems a lot of useful qualities for blender to pick up on… and that also file size is not such an issue provided your hardware is fairly quick or your movie resolution not too big…and it looks like Indigo output could be dealt to effectively too using the node compositor :smiley:

Man Blender is just so cool these days :slight_smile:

well if you are compositing or rendering, then the format doesn’t need to be fast… you don’t save it to that format for final screening.


The new EXR format shurely is a great step forward to handle pictures inside of Blender in a professionell way, but…

  • No other programm can read EXR 32 Bit MultiLayer files.PS for instant opens the file, but doesn`t show Layers. Can Gimp open HDRI or EXR Files ? Until today its an island solution.
  • By the way. Is it possible to export single Passes out of Blender. I found no way to do this. If this was true, one cannot manipulate the passes in Gimp or PS.

On other programs reading the format: not yet, at least. I tried the PS plugin for reading OpenEXR and it is very basic. The particular way that Blender saves the render layers and passes with EXR follows a new spec that Ton got from the OpenEXR group called (hmmm) BlenderLayeredSpec (or something like that, it’s on the release notes page). So, while no one else can import and use it yet, it just takes one schmo with a compiler and a free weekend to make the appropriate importer for PS and all compatible image processing apps.

My understanding is that while most Blenderheads won’t need to save as .exr for their hobbiest purposes for pro aspiration stuff you could indeed save all your work as .exr. and read it back thru a decent pc for studio quality editing.
Its sort of like a super format that holds the master info that you can then manipulate and save down for distribution as dvd or for cinema projection.
A bit like having digital masters for music and then making mp3 from it.
The fact that this is available in free Blender is amazing.

It seems like someone really needs to make a PS plugin soon then…if possible for the next release because Blender will get a lot of attention again and it would be good to have something for the hard to convince mainstream cg guys to play with…(ah I wish I could code :o )
Multilayer .exr would seem to be the cutting edge application of exr and its only available in lil ol’ Blender.
wow :eek: :smiley:

I want a plugin, not to impress other people, but to manipulate the passes in PS. I´am familar with Ps or Gimp. Everything I can do with Nodes and much more -with a higher range of functionality and a better controll- I could do within PS. From a certain (early) point of complexity, nodes get messy .

sorry you don’t like blender nodes so much :slight_smile:
maybe someone makes the PS plugin for you anyway :wink:

I will wait patienly.:smiley:
Its fantastic, that Blender calculates with 32 Bits, because this offers the possebility to render your own hdri pictures for the world background. Wonderfull. I see all the advantages of the new format and its realy usefull to have only one format to store all informations. Very professionell…
Perhaps we will get a 16 Bit EXR version soon :smiley: