EXR Data Window
I'm currently investigating Migrating to Blender. I have noticed that there doesn't appear to be any options for a Data Window in EXR output. This might seem like a little thing however when it comes to animation render outputs the amount of space savings for transfers, memory savings during composite, and overall quality of life can be enormous. Also the exr standard allows for data windows for multi-part/multi-layer which can take those savings to the next level.
I would love to see that implemented in further 3.x releases.
5 Comments
Just a comment on this idea. EXR data windows can have a massive impact in compositing. Using Nuke, you can have speed ups of over 10x in the correct circumstances. Memory savings can be massive too. In my workflow, it would even be enough to have the Render Region get saved into EXR as the data window.
You can save passes into EXR files using the EXR multilayer output. What do you imply by an "EXR data window"?
The best way I know how to describe it would be as a crop box. With many image formats pixels which have no RGBA or other channel values still contain information leading to a non trivial amount of file bloat. With EXR the Data Window can define a rectangular box outside of which no pixel information is stored. It can even store pixel information not contained within the Display Window. Currently I'd have to use OIIOtool as a post render process on Blender renders. For more information and probably a better explanation page 5-6 may help
openexr.com/documentation/TechnicalIntroduction.pdf
Missing of this feature makes impossible to composite renders coming from other render engine that utilize it. The image with alpha would jump all over the frame.
I can only agree, this can speedup your comps (when using a compositor that "understands" data windows, like Nuke or Fusion), reduce file size, transfer times, the time to open a flipbook etc. And it's completely supported by OpenEXR since forever. Should be low hanging fruits for a developer to take.