Hiero: thumbnail from multilayer exr

[jakubjezek001]

Brief description

Hiero exctract thumbnail works on mutlilayer exr

Description

Thumbnail creator needed to have specified color layer.

Testing notes:

1. Open hiero workfile
2. add multilayer exr at timeline
3. Create publishable clip on the new clip
4. publish
5. see that all works well

[ynbot]

Task linked: OP-4407 Hiero | Extract Thumbnail error

[jrsndl]

This works for multilayer EXRs that have a colour channel [1].
Unfortunately it fails on EXRs with tech passes only, that often do not have any colour [2].

[jakubjezek001]

This works for multilayer EXRs that have a colour channel [1].
Unfortunately it fails on EXRs with tech passes only, that often do not have any colour [2].

I wonder if this is not edge case nobody will hit in production. Yes we are having only colour layer set for thumbnail. I can do exception to soft fail in case no colour pass is present, because it is quite difficult to define which of technical passes should be used for thumnails.

[jrsndl]

exception to soft fail in case no colour pass is present, because it is quite difficult to define which of technical passes should be used for thumnails.

Either that, or if you can pull the list of layers from Hiero, just take a first one if colour is not present?

[jakubjezek001]

exception to soft fail in case no colour pass is present, because it is quite difficult to define which of technical passes should be used for thumnails.

Either that, or if you can pull the list of layers from Hiero, just take a first one if colour is not present?

I would wrap this known limitation and not to waste time on it, since this is quite unlike edge case.

[jakubjezek001]

@jrsndl there is missing api support on Hiero to get list of available layers from a clip. I had tested the workaround with nuke.layers(node) but this works only in Nuke environment.

[jrsndl]

Works for multilayer EXRs that have colour (rgb/rgba) layer