  In this work, we introduce our method of outdoor scene relighting for Neural
Radiance Fields (NeRF) named Sun-aligned Relighting TensoRF (SR-TensoRF).
SR-TensoRF offers a lightweight and rapid pipeline aligned with the sun,
thereby achieving a simplified workflow that eliminates the need for
environment maps. Our sun-alignment strategy is motivated by the insight that
shadows, unlike viewpoint-dependent albedo, are determined by light direction.
We directly use the sun direction as an input during shadow generation,
simplifying the requirements of the inference process significantly. Moreover,
SR-TensoRF leverages the training efficiency of TensoRF by incorporating our
proposed cubemap concept, resulting in notable acceleration in both training
and rendering processes compared to existing methods.
