  Decoupling lighting from geometry using unconstrained photo collections is
notoriously challenging. Solving it would benefit many users, as creating
complex 3D assets takes days of manual labor. Many previous works have
attempted to address this issue, often at the expense of output fidelity, which
questions the practicality of such methods.
  We introduce LumiGauss, a technique that tackles 3D reconstruction of scenes
and environmental lighting through 2D Gaussian Splatting. Our approach yields
high-quality scene reconstructions and enables realistic lighting synthesis
under novel environment maps. We also propose a method for enhancing the
quality of shadows, common in outdoor scenes, by exploiting spherical harmonics
properties. Our approach facilitates seamless integration with game engines and
enables the use of fast precomputed radiance transfer.
  We validate our method on the NeRF-OSR dataset, demonstrating superior
performance over baseline methods. Moreover, LumiGauss can synthesize realistic
images when applying novel environment maps.
