It’s part of the Unreal Engine 5.5 Preview 1 just released at Unreal Fest Seattle.
More on MegaLights here from Unreal Engine:
During today’s opening session, we gave a live demonstration of a new Experimental feature: MegaLights, which enables you to use orders of magnitude more lights than ever before—all movable, dynamic, with realistic area shadows and the ability to light volumetric fog. In the demo, our intrepid hero Echo navigated a scene illuminated by over 1,000 shadow-casting lights in real time running on PlayStation 5.
