OCIO + nDisplay ?

Development Rendering
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1

I asked a question a couple of months ago about compatibility between OCIO and nDisplay: [Content removed] We maintain a plugin that uses nDisplay and in UE 5.5 and previous versions worked fine when using OCIO but not in 5.6. The thread was closed because it couldn’t be repro’d without going through the plugin and I wanted to do more investigating into why this was happening.

I was looking at recent changes in the nDisplay files and came across this snippet in DisplayClusterViewportConfigurationHelpers_OpenColorIO.cpp line 91:

if (!DstViewport.Configuration->GetRenderFrameSettings().IsEnabledOpenColorIO())
{
  // OCIO is disabled for nDisplay.
  DisableOCIOConfiguration(DstViewport);

  return;
}

What intrigues me here is the comment. Is it not intended for OCIO to be compatible with nDisplay anymore ? After doing some debugging it turns out that this code is never actually reached. My theory is that somewhere else OCIO + nDisplay was broken and this was put here to make sure it gets disabled but when running through our plugin the checks don’t pass so it doesn’t get disabled. This could explain why the colour seems so off to me but not when running normal nDisplay. I’m not 100% sure though. Could anyone confirm if this comment is true and OCIO + nDisplay support is not longer valid ?

2

I think that is for the case where OCIO is disabled in the Preview. For example if the OCIO config does PQ encoding the the preview in the editor will not look correct because it is not reversing that encoding. But OCIO is critical for nDisplay especially for HDR via PQ and will always be supported.