Recap - sorry for the delay!
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@matthias.scharfenber demoed a Nuke script to show:
- Multiple applications of the gamut compression
- Results of inverse on renders that did not have the forward transform applied
- We established that without parameter modification, the tracking of the algorithm could be done using the current AMF spec (in an LMT slot)
- Then the topic of parameterization was discussed:
- @hasche and @matthias.scharfenber pointed out that exposing parameters could be useful in comp as well as color grading (green screens might be out of gamut, etc)
- Even though the blue > magenta hue shifts are Output Transform related, they can be slightly mitigated through gamut compression and that might be desirable
- How to handle the desire to parameterize vs. the need to track?
- @KevinJW suggested two options: the official ACES Gamut Compression which would be static and trackable via AMF, and then another separate operator of a different (TBD) name, which could expose parameters in Nuke, Resolve, Baselight
- This second option would be treated like any other operation in comp that changes colors (despill, etc) and would not need tracked because you’d never want to go back
- @mario suggested separating the thought process as technical vs creative in our documentation
- We discussed briefly that negative values still remain in the noise floor post gamut compression, and that this is intended - pointed to earlier versions of the algorithm in @jedsmith’s repo if folks want an idea of how to solve that separately. But it was not included in the final algorithm to maintain exposure invariance for invertibility.