Unreal with built project & genlock questions

Hi! We’re trying to develop a workflow that allows us to use Blender for realtime graphics rather than Unreal, for various reasons. Right now the big problem we’re trying to overcome is synchronous rendering across multiple nodes.

With Unreal and nDisplay, we can tell each node to only render a certain portion of a whole image (by pixel coordinates.) We can do the same with Blender with render regions, but there’s no way to ensure the rendering is actually synchronized. Our idea is to build a program with Unreal that reads genlock/timecode from a Blackmagic card and sends that data via OSC to Blender to trigger a render, and simultaneously shares that data with Lightact. The Lightact instances would communicate together with Lightsync.
Of course, all output nodes will also be sync’d together with Quadro Sync,

My first question is if this approach seems valid, or if there’s something on the Lightact side that I’m missing.

My second question is if the Lightact plugin still works if the project is packaged into an .exe, as for this we ideally wouldn’t need to run the whole UE editor just to get and pass timing information.



I’m not 100% sure I understand everything. The main question is actually, what role does LightAct play here? :slight_smile:

As to your second question, yes, our plugin works with packaged Unreal projects as well.


Hi Meetya!

In this case, Lightact would act as the central point for the rendered images–taking them in via NDI or SDI, combining them back into a full image, and then projecting them onto a mesh representing the screen based on camera tracking data.


This should work yes, but please note that at the moment:

  • LightAct supports only FreeD and Stype tracking data. What are you planning to use?
  • lens distortion is not implemented (from Stype data)


Awesome! Those limitations are totally fine. We mostly use Optitrack, so we can get FreeD data no problem. And we don’t use any foreground elements, so lens distortion is not a factor.

Oh, we support optitrack, blacktrax and PSN too. Was talking only about camera tracking technologies specifically before…

Best regards,