DMX Visualization: CTC, Color XF, and G/M Tint Functions not affecting virtual lights inside UE Editor

Hello!

I am in the process of building out a digital twin of an ICVFX/XR stage and creating a tech-visualization workflow in UE 5.3.2. I am using the DMX plugin’s Blueprint fixture, BP_StaticHead, as placeholders for physical studio light fixtures (Arri L7-Cs, l10-Cs, Orbiters, SkyPanel S60-Cs, etc.) I have setup DMX communication with a Chamsys MagicQ-50 so that when I adjust the attributes of the lights on the board the changes are also visualized inside of the UE editor. However, there is a problem.

Although I have correctly mapped and patched the DMX functions, the Color XF, CTC, and G/M tint functions are not affecting the virtual light. The RGB and dimmer functions work properly, so I’m wondering: does this functionality currently exist in the DMX plugin? Is this a bug in 5.3.2? Is there a way to fix the BP so that I can properly visualize the light’s color temperature?

I would greatly appreciate any support from the Epic Games Virtual Production Team or any community members that have encountered similar issues.

Thanks,
Sam Brown

Hey Sam,

So, the problem you’re running into with those functions is that they don’t exist on the virtual fixtures in Unreal. If you go into Project Settings>Plugins>DMX and scroll down to fixture settings, you can open up the “fixture attributes” section and see the different attributes that the plugin is already set up to accept. These are, in turn, the functions you can choose from when you set up your fixture in your DMX Library.

By default, by defining/adding an attribute there, all it does is allow you to take in the data on the channel(s) that you set for that function in the DMX Library and then access it from the “OnDMXPatchRecieved” event in the fixture blueprint.

SOME of those attributes have had actual functionality written for them in the example fixtures (RGB, dimmer, gobo, tilt, pan, . . . Pretty much the stuff you see in the example levels), but not all of them. And if you make your own fixture from the DMXFixtureActorBase, you’ll have to write your own functionality for all of them (as well as assemble the fixture, itself, from whatever meshes). But you can also make a copy of an existing fixture blueprint and add to what is already there.

So, basically, it comes down to how important those functions are to you right now. You can add them to the plugin settings, and that will at least allow you to record those settings from Chamsys into sequencer, if you were looking to do that and then eventually play that back out on the actual physical fixtures or something. If you’re only ever messing around with them in the virtual world, though, you can either pull off of the Value Per Attribute Map on the “On Fixture Patch Received” event, and do a “find” node, and select your attribute and build the functionality, or you can just account for them in the DMX Library so that your channel spacing doesn’t get messed up between the Chamsys and Unreal and ignore them otherwise.

Hope this helps you out a little bit!

Steve

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