Review for NeurIPS paper: Multiview Neural Surface Reconstruction by Disentangling Geometry and Appearance

Clarity: As written, I find the explanation of the "implicit differentiable renderer" to be highly misleading. Throughout the paper, the network M is described as a "differentiable renderer" that accounts for both BRDF and lighting conditions. Indeed, the TITLE of the paper implies that lighting and materials are being recovered in the style of full inverse rendering. Section 3.2 introduces the rendering equation and makes a big deal about specifying the BRDF and light sources. However, this is all rendered pointless by lines 155-156: "Replacing M0 with a (sufficiently large) MLP approximation M provides the radiance approximation…" Rolling up all these factors into one big function means you are learning a surface light field, nothing more.