The SIAM Special Interest Activity Group on Geometric Design and the ACM Symposium on Solid and Physical Modeling have a shared heritage dating back to the early 1980s. This biennial joint conference (started in 2009) represents a historic union of these communities, their rich academic and industrial histories, as well as the common intellectual themes that continue to move them forward. Over the past twenty years the meetings of the SIAM Special Interest Activity Group on Geometric Design have been one of the main general international conferences on geometric modeling and related areas, and have been well attended by mathematicians and engineers from academia, industry, and government. Since its inception in 1991, the ACM Symposium on Solid and Physical Modeling has been the primary international forum for disseminating research results and exchanging new ideas in relevant mathematical theory, solid modeling, physical modeling, geometric design, analysis, simulation and processing, shape computing and visualization, and various applications. The 2013 SIAM Conference on Geometric and Physical Modeling seeks high quality, original research contributions that strive to advance all aspects of geometric and physical modeling, and their application in design, analysis and manufacturing, as well as in biomedical, geophysical, digital entertainment, and other areas (see the list of conference topics below). A shared objective of both the SIAM GD and ACM SPM communities is a desire to highlight work of the highest quality on the problems of greatest relevance to industry and science. In ACM SPM tradition, the conference will include a track for submission of peer-reviewed technical papers for those wishing rigorous peer review and published proceedings. In addition, in the tradition of previous SIAM GD events, abstracts for minisymposia and contributed talks/posters are solicited.