Using OCIO with ARFX

Using OCIO with ARFX

OCIO (OpenColorIO) is a color management solution geared towards film production. Although Unreal does support the format, it does not have support for scenes that require Play In Editor to function like with ARFX Cameras. The only way to get around this is to use a Level Blueprintt that tells Unreal to use a specific OCIO configuration at runtime.

First, make sure the OCIO Plugin is enabled by going to Edit > Plugins > and search for OCIO.  

To get to the Level Blueprint, you go to this option here in the Editor Toolbar.      

Drag out a line from BeginPlay and search for Create in game to find the above.  

Next, you drag out a line from “In Display Configuration” to then click on Promote to Variable. You can rename the variable created to whatever you wish.  

You should now have something like this in your Blueprint. Hit the Compile button before proceeding.  

Select the variable Blueprint and find its Default Value. Here, make sure it is enabled and that you’ve specified the configuration file you wish to use. Note that you must create this configuration file yourself if you have not already done so. You can do this by selecting OpenColorIO Configuration under Create New Asset from the drop-down menu.        

You can import an OCIO configuration file from third-party software by editing the OpenColorIO Configuration asset, which can be created as noted in the above image. It is a fairly straightforward process, just be sure to save after you’ve imported and press Compile in the blueprint again for Transform Source and Transform Destination to properly update themselves.

One last step is to ensure that you are using the proper Color Space in Unreal. To do this, go to Edit > Project Settings > Engine > Rendering > Working Color Space. Set the color space to your preference using the drop-down menu and restart the Editor.  

Important

It is unclear if you have to take this last step as the scene will be running while in Play. It is best to do it anyway just to be sure.

You should now be able to use Play In Editor along with your OCIO configuration!

Using LUTs instead of OCIO.

Unreal was built with LUTs in mind, and it is actually recommended that you convert your OCIO into LUTs instead. For more information regarding how to do this, please visit Unreal’s Tutorial: UnrealOCIOLUT.