The creator utilized Unreal's Nanite and Lumen to set up the scene.
3D Artist Yan Ru, known for creating outstanding environments with Unreal Engine, has unveiled a gorgeous real-time 3D scene that depicts a grandiose Baroque-style ballroom. According to the creator, the level was set up with 3ds Max and Unreal Engine 5.1, using the latter's Lumen and Nanite features to display hundreds of millions of triangles on the screen. Moreover, the author has also shared the scene as a free downloadable file, which you can access here.