This paper presents a novel neural implicit radiance representation for free
viewpoint relighting from a small set of unstructured photographs of an object
lit by a moving point light source different from the view position. We express
the shape as a signed distance function modeled by a multi layer perceptron. In
contrast to prior relightable implicit neural representations, we do not
disentangle the different reflectance components, but model both the local and
global reflectance at each point by a second multi layer perceptron that, in
addition, to density features, the current position, the normal (from the
signed distace function), view direction, and light position, also takes shadow
and highlight hints to aid the network in modeling the corresponding high
frequency light transport effects. These hints are provided as a suggestion,
and we leave it up to the network to decide how to incorporate these in the
final relit result. We demonstrate and validate our neural implicit
representation on synthetic and real scenes exhibiting a wide variety of
shapes, material properties, and global illumination light transport.

本研究提出了一种新颖的神经隐式亮度表示方法，用于从一小组不规则的物体照片中进行自由视角重照。我们通过多层感知器将形状表示为有符号距离函数。与先前的隐式神经重照方法不同，我们没有分离不同的反射分量，而是通过第二个多层感知器在每个点上模拟局部和全局反射，并融合阴影和高光提示来辅助网络对应的高频光传输效果建模。在合成和真实场景中展示和验证了我们的神经隐式表示方法，这些场景具有各种形状、材料属性和全局光照传输。