Sculpt and sketch interfaces for 3D modeling

素描和雕塑是数千年来视觉交流的媒介。从计算的早期开始，早在Ivan Sutherlannd开创性的Sketchpad系统（1963年），基于草图或造型隐喻的界面就被吹捧为3D建模的“自然”方法。在过去的二十年里，已经出现了许多有前途的草图或基于雕刻的3D建模系统，但将视觉创意转换为数字3D模型的中心目标仍然是正在进行的研究的一个肥沃的领域。在过去的5年里，我的研究最终成功的3D建模系统：ILoveSketch和解析3D绘图（基于草图），Shapeshop3D和MeshMixer（基于雕塑）。计算机图形学中的这一研究和类似的研究在很大程度上忽略了人类视觉感知研究的重要主体，该研究研究了人类对3D形状的感知和理解中的各种偏见和固有限制。因此，该提案旨在通过首先尝试对我们对3D形状的感知中的各种偏见进行计算建模，来更严格地探索3D形状建模的雕刻和草图。例如，众所周知，当被要求从倾斜视图绘制立方体时，人类会在深度上显著拉长它。如果没有这种偏差的模型，计算机会错误地推断出这幅画是一个细长的长方体。相反，一个数字立方体，如果没有纠正我们的视觉偏见，在我们看来就像一个被压扁的长方体。因此，拟议研究的一个重要方面将建立在人类感知，形状理解，抽象和艺术美学的研究基础上，并测试和模拟与视觉感知偏差有关的各种假设。尽管存在3D输入设备和显示器，但今天使用的大部分输入设备和显示器仍然是2D的。即使有一个很好的模型，在人类perection的偏见，从2D输入推断3D形状的模糊性是什么使数字3D建模一个独特的挑战性问题。有两种方法可以解决这个基本问题：通过构建更好的推理引擎，使用3D形状的上下文和可能性模型来解决歧义（例如，分析3D绘图）或通过构建更好的界面和交互式工作流程，允许用户增强其2D输入并明确表达其预期的3D形状（例如，ILoveSketch）。本研究将继续探索这两个研究方向。 最后，现实世界数据的数字化获取的进步使艺术家可以将传统媒体作为数字创作过程的一部分。因此，挑战不再是数字化地捕捉传统素描或雕塑的启示，而是让用户在他们选择的媒介（物理或数字）中工作，并将任何真实世界的数据与工作的数字模型相协调。这将是拟议研究的另一个方面。

Sketching and sculpting have been the medium of visual communication for millenia. Since the early days of computing, as far back as Ivan Sutherlannd's seminal Sketchpad system (1963), interfaces based on a sketch or sculpt metaphor have been touted as "natural" approaches to 3D modeling. The last two decades have seen a number of promising sketch or sculpt based 3D modeling systems but the central goal of transforming a visual idea into a digital 3D model continues to be a fertile area of ongoing research. In the past 5 years my research has culminated in successful 3D modeling systems: ILoveSketch and Analytic 3D drawing (sketch-based), Shapeshop3D and MeshMixer (sculpt-based). This and similar research in computer graphics has been largely oblivious of an important body of research in human visual perception that studies the various biases inherent limitations in human perception and understanding of 3D shape. This proposal thus intends to explore sculpting and sketching for 3D shape modeling with greater rigour by first attempting to computationally model the various biases we have in our perception of 3D shape. For example, it is well-known that when asked to draw a cube from an oblique view, humans elongate it in depth significantly. Without a model for this bias, a computer would erroneously infer the drawing to be an elongated cuboid. Conversely, a digital cube, if displayed without correcting for our visual bias, would appear to us as a squashed cuboid. A significant aspect of the proposed research will thus build upon prior research in human perception, shape understanding, abstraction and aesthetics in art and test and model various hypotheses relating to biases in visual perception. Despite the existence of 3D input devices and displays, the bulk of input devices and displays in use today continue to be 2D. Even with a good model of the biases in human perecption the ambiguities in inferring 3D shape from 2D input is what makes digital 3D modeling a uniquely challenging problem. There are two ways to address this fundamental problem: by building better inference engines that use context and likelyhood models of 3D shape to resolve ambiguities (eg. Analytic 3D drawing) or by building better interfaces and interactive workflows that allow users to augment their 2D input and explicitly express their intended 3D shape (eg. ILoveSketch). This research will continue to explore both these research directions. Finally, advances in the digital acquisition of real-world data now make it possible for artists to use traditional media as part of the digital creative process. The challenge is thus no longer to digitally capture the affordances of traditional sketching or sculpting but instead to let users work in a medium of their choice (physical or digital) and reconcile any real-world data with a working digital model. This shall be yet another facet of the proposed research.