Open MrLixm opened 8 months ago
Test around the "print contrast" options. The initial release put it after the second tonescale but before it is linearized.
put the Print contrast sigmoid parabolic after the linearisation.
sandwich the sigmoid parabolic between Log Shapers (still after linearization)
The outset is currently behind a linearize sandwich and applied after the first tonescale. The amount is driven by a simple lerp (NodeWrapper node) between the input of the outset and its output.
remove the linearized sandwich
Test the effect of the second Inset (part for the second tonescale section).
For that we disable the second log shaper + tonescale.
The second inset has default value of inset:0.4, r: 0.06, g: 0, b: 0.06 while first inset has values of inset: 0.4, r: 0.125, g: 0, b: 0.15
^ without second inset
^ with second inset, same global inset values as first inset (r,g,b inset are different)
^ removed the outset and the second inset
^ changed the second inset so its value perfectly match the first inset. It's a perfect match as if we remove outset+second inset.
Something I wanted to tackle since the beginning. I'm not even sure those words are accurate to describe the issue but again keeping in lack of better. This is of course in reference to the Eary and other Blender-Artist folks implementation: https://github.com/EaryChow/AgX_LUT_Gen/blob/main/luminance_compenstation_bt2020.py
While experimenting with grading under the AgXcDRT I stumbled on a cool side effect of operating on chroma in isolation of luma. Let me showcase it :
^ default AgXcDRT with no compensation
^ default AgXcDRT with compensation applied
The effect is most visible on the green dragon cg render.
The algorithm consist in :
The algorithm is as follows :
Again no idea why it works, but it does.
The observed issue with the current implementation are that it fix high values, but not low values as you can see on the green dragon. This can be addressed by removing the lerp with luma, but which create highly natural "brilliant" colors, especially the blue.
This will act as a logbook for the further investigation of the AgXc DRT for Nuke that was release in v0.10.0.
I will note anything that I found that could help improve it.