The pre-release of the first version of Unreal Engine 4 (back in 2012) had Sparse Voxel Octree lighting but it was too expensive for practical use in games
“The key differentiating factor between last year’s demo and this newer iteration is that the Sparse Voxel Octree Global Illumination (SVOGI) lighting system hasn’t made the cut. Instead, Epic is aiming for very high quality static global illumination with indirect GI sampling for all moving objects, including characters.”