PhySG: Inverse Rendering with Spherical Gaussians for Physics-based Material Editing and Relighting (2104.00674v1)

Abstract: We present PhySG, an end-to-end inverse rendering pipeline that includes a fully differentiable renderer and can reconstruct geometry, materials, and illumination from scratch from a set of RGB input images. Our framework represents specular BRDFs and environmental illumination using mixtures of spherical Gaussians, and represents geometry as a signed distance function parameterized as a Multi-Layer Perceptron. The use of spherical Gaussians allows us to efficiently solve for approximate light transport, and our method works on scenes with challenging non-Lambertian reflectance captured under natural, static illumination. We demonstrate, with both synthetic and real data, that our reconstructions not only enable rendering of novel viewpoints, but also physics-based appearance editing of materials and illumination.

• The paper introduces PhySG, a new framework that leverages spherical Gaussians for accurate inverse rendering in material editing and relighting.
• It employs a physics-based formulation to decouple material properties from lighting, enabling flexible and realistic scene manipulation.
• Experimental evaluations demonstrate improved visual fidelity and robust performance under varied lighting conditions, supporting practical applications in computer graphics.

Overview of the CVPR LaTeX Guidelines for Author Response

The document titled "LaTeX Guidelines for Author Response" targets authors preparing rebuttals after receiving paper reviews, specifically for CVPR (Conference on Computer Vision and Pattern Recognition) submissions. The guidelines delineated herein address style and format expectations, with a critical emphasis on ensuring rebuttals are succinct, relevant, and devoid of new, supplemental data that were not part of the original submission.

Rebuttal Objective and Constraints

The primary objective of an author rebuttal, as stated in the document, is to address factual inaccuracies and to provide additional information that may assist reviewers without introducing novel contributions such as new theorems, algorithms, or experimental results. The submission should be strictly confined to the parameters of one-page PDF, ensuring conciseness and focused content reflective of the initial submission's scope. Notably, this paper reinforces a key policy from a PAMI-TC motion enacted in 2018, which stipulates that reviewers are discouraged from seeking further experiments for the rebuttal. Explicitly, any additional experimental results provided within a rebuttal are to be disregarded during final evaluations.

Format Specifications

Adherence to format specifications is crucial and non-negotiable. The document prescribes a two-column layout, with specific dimensions in terms of width and height, tailored for compatibility with both US Letter and A4 paper sizes. Key attention to detail is required in configuring text fonts, margins, and paragraph indentation, ensuring a cohesive and professionally presented document.

The paper stresses that authors must maintain consistency with the format guidelines, such as using Times or Times Roman typeface for main text (10-point), while section headings may opt for a slightly larger size (up to 12-point). Illustrations, graphs, and photos should be centralized and maintain a quality that translates effectively when printed, as many readers and reviewers may prefer a hard copy evaluation.

Implications for Authors and Reviewers

Intrinsically, these guidelines shape the manner in which authors respond to critiques, emphasizing a strategic focus on clarity and the substantiveness of arguments without diverging into fresh contributions. This constraint presents both a challenge and an opportunity for researchers to succinctly defend their work within a rigid template that ensures a level playing field across submissions.

For reviewers, the emphasized guidelines constrain the evaluation process to the contents and scope of the original paper and rebuttal, limiting judgments to the arguments presented without bias influenced by new experimental data.

Future Considerations

The guidelines presented can potentially evolve, addressing emerging concerns in academic integrity and fairness in assessments. Future developments may explore more interactive rebuttal formats or integrate technological innovations that can synthesize reviewer-author interactions, streamlining the process while retaining the core value of fair evaluation.

This document's systematic approach simplifies the rebuttal submission process for authors and ensures an equitable assessment framework for reviewers, contributing positively to the dissemination and evaluation of scientific advancements in the CVPR community. As the fields of computer vision and pattern recognition advance, such institutional structures are crucial to maintaining high standards in scholarly discourse.