Multichannel exr - maya - thumbnails - convert - imagemagick - linux

[brother john]

Posting this in case it helps others are using multichannel exrs. I have only tested in our environment which are blades running centos7.
We were not getting thumbnails when using multichannel exr's as, it turns out, imagemagick cannot read them.
As an alternative, OpenImageIO can at least read the RGB of, I am supposing, the first encountered channel.

Solution was simple. I found a copy of it (oiiotool) was already in:
/usr/autodesk/arnold/maya2023/bin/oiiotool

I copied it to our network repo and chmodded it to be exectuable and usable by cgru user.
Then added this to config.json:

Code: Select all

"":"Thumbnail:",
	"af_thumbnail_extensions":["exr","dpx","jpg","jpeg","png","tif","tiff","tga"],
	"af_thumbnail_cmd":"/path/to/cgru_3.3.1_blade/utilities/oiiotool \"%(image)s\" -resize 177x100 -o \"%(thumbnail)s\"",
	"af_task_post_limit_sec":16,
		"":"Task post command running time limit in seconds.",
		"":"Task post commands used to generate thumbnails."

Reread of config by restarting the blades, and should be working.
To check, after each frame finishes rendering, it then creates the thumbnail, so you can see that operation at the end of the frame log.

Thankfully Timur has written CGRU in such a way that this was super easy to simply use another converter.
Big thanks again Timur!

Just a note, you can probably find out what user cgru is running as if you place "whoami;" in the conversion command line and check the end of the log.
eg.

Code: Select all

"af_thumbnail_cmd":"whoami;/path/to/cgru_3.3.1_blade/utilities/oiiotool \"%(image)s\" -resize 177x100 -o \"%(thumbnail)s\"",

BrotherJohn

[timurhai]

Thank you!
It seems that CentOS7 native imagemagick package is too old for such exrs.

The other solution is to complie modern imagemagick from sources manually and use it on farm (we do so).
Imagemagick doesn't stand still, now it suppors and multi-channel and over-resolution bounding box exrs.

[brother john]

Oh that's great to know! I searched but couldn't find any mention of adding multichannel support, hence the route I took, but yeah, maybe I might do the compile and see if that works. Thanks for that Timur!