Problem summary
The premultiplied knob on the Read node does not work for exr/dpx/mov/mxf files when using OCIO color management
This happens with ACES and nuke-default configs, and doesn't affect tga, sgi, pic, tiff and png files
Customer reported version
nuke.n/a
Customer reported platform
Steps to reproduce
1) Launch Nuke and open the attached Nuke script
2) Select Render>Render All Write nodes..., and render 1 frame
3) View the different Read nodes, reloading them if needed. When toggling the Premultiplied knob on and off, there should be a difference
Expected behaviour
For the Premultiplied knob to apply to the exr/dpx/mov/mxf files when using OCIO:
Actual behaviour
The knob does nothing
Workaround
When enabled, the premultiplied knob should correct the color of the partially transparent pixels produced by most renderers by dividing color data by the alpha channel before converting from the colorspace, and then multiplying by the alpha channel afterwards. This can be done manually by:
1) In the Read node, enable the Raw Data knob
2) Add an Unpremult node
3) Add an OCIOColorspace node, and apply the transform, in this case setting the input knob to sRGB
4) Add a Premult node
Reproduced by support
This bug has been reproduced in:
Nuke 15.1v3 - Windows 10, macOS Sonoma, Rocky 9.3
Nuke 12.0v1 - Windows 10
Earliest version tested
Nuke 12.0v1 - This issue appears to be in all tested versions of the product
