Reconstruction of machine-made shapes from bitmap sketches

We propose a method of reconstructing 3D machine-made shapes from bitmap sketches by separating an input image into individual patches and jointly optimizing their geometry. We rely on two main observations: (1) human observers interpret sketches of man-made shapes as a collection of simple geometric primitives, and (2) sketch strokes often indicate occlusion contours or sharp ridges between those primitives. Using these main observations we design a system that takes a single bitmap image of a shape, estimates image depth and segmentation into primitives with neural networks, then fits primitives to the predicted depth while determining occlusion contours and aligning intersections with the input drawing via optimization. Unlike previous work, our approach does not require additional input, annotation, or templates, and does not require retraining for a new category of man-made shapes. Our method produces triangular meshes that display sharp geometric features and are suitable for downstream applications, such as editing, rendering, and shading

DeepSketch2Face: A Deep Learning Based Sketching System for 3D Face and Caricature Modeling

Face modeling has been paid much attention in the field of visual computing. There exist many scenarios, including cartoon characters, avatars for social media, 3D face caricatures as well as face-related art and design, where low-cost interactive face modeling is a popular approach especially among amateur users. In this paper, we propose a deep learning based sketching system for 3D face and caricature modeling. This system has a labor-efficient sketching interface, that allows the user to draw freehand imprecise yet expressive 2D lines representing the contours of facial features. A novel CNN based deep regression network is designed for inferring 3D face models from 2D sketches. Our network fuses both CNN and shape based features of the input sketch, and has two independent branches of fully connected layers generating independent subsets of coefficients for a bilinear face representation. Our system also supports gesture based interactions for users to further manipulate initial face models. Both user studies and numerical results indicate that our sketching system can help users create face models quickly and effectively. A significantly expanded face database with diverse identities, expressions and levels of exaggeration is constructed to promote further research and evaluation of face modeling techniques.Comment: 12 pages, 16 figures, to appear in SIGGRAPH 201

Design and Manufacturing of a Prototypical Assembly of an Inline-four Engine Using Rapid Prototyping Technology

Bakalářská práce se zabývá tématem prototypování a tvorbou 3D modelu jako součásti procesu produktového vývoje. Prototypový model motoru je konstruován s využitím parametrické aplikace CATIA v5 a vyroben s použitím aditivní výrobní technologie– metoda Fused Deposition Modeling. Teoretická část práce se věnuje problematice produktového vývoje, aditivní výroby a řadou konstrukčních a funkčních charakteristik motoru. Praktická část práce pak popisuje proces návrhu a výroby prototypového modelu motoru. Práce je ukončena technicko-ekonomickým zhodnocením navržené sestavy.The bachelor’s thesis focuses on the topic of prototyping and 3D model–making as a part of the product development process. The model is designed with the use of CATIA v5 parametric application and it is manufactured with the use of Additive Manufacturing technology–Fused Deposition Modeling. The theoretical part of the thesis addresses the topic of Product Development, Additive Manufacturing technology as well a number of engine design and functional characteristics. The experimental part of the work then describes the process of designing and manufacturing of the engine model. The work is concluded with a techno-economic evaluation of the designed assembly.

Stroke-Based Stylization Learning and Rendering with Inverse Reinforcement Learning

Among various traditional art forms, brush stroke drawing is one of the widely used styles in modern computer graphic tools such as GIMP, Photoshop and Painter. In this paper, we develop an AI-aided art authoring (A4) system of non- photorealistic rendering that allows users to automatically generate brush stroke paintings in a specific artist’s style. Within the reinforcement learning framework of brush stroke generation proposed by Xie et al.[Xie et al., 2012], our contribution in this paper is to learn artists’ drawing styles from video-captured stroke data by inverse reinforcement learning. Through experiments, we demonstrate that our system can successfully learn artists’ styles and render pictures with consistent and smooth brush strokes

Calipso: Physics-based Image and Video Editing through CAD Model Proxies

We present Calipso, an interactive method for editing images and videos in a physically-coherent manner. Our main idea is to realize physics-based manipulations by running a full physics simulation on proxy geometries given by non-rigidly aligned CAD models. Running these simulations allows us to apply new, unseen forces to move or deform selected objects, change physical parameters such as mass or elasticity, or even add entire new objects that interact with the rest of the underlying scene. In Calipso, the user makes edits directly in 3D; these edits are processed by the simulation and then transfered to the target 2D content using shape-to-image correspondences in a photo-realistic rendering process. To align the CAD models, we introduce an efficient CAD-to-image alignment procedure that jointly minimizes for rigid and non-rigid alignment while preserving the high-level structure of the input shape. Moreover, the user can choose to exploit image flow to estimate scene motion, producing coherent physical behavior with ambient dynamics. We demonstrate Calipso's physics-based editing on a wide range of examples producing myriad physical behavior while preserving geometric and visual consistency.Comment: 11 page

Hybrid sketching : a new middle ground between 2- and 3-D

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Architecture, 2005.Includes bibliographical references (leaves 124-133).This thesis investigates the geometric representation of ideas during the early stages of design. When a designer's ideas are still in gestation, the exploration of form is more important than its precise specification. Digital modelers facilitate such exploration, but only for forms built with discrete collections of high-level geometric primitives; we introduce techniques that operate on designers' medium of choice, 2-D sketches. Designers' explorations also shift between 2-D and 3-D, yet 3-D form must also be specified with these high-level primitives, requiring an entirely different mindset from 2-D sketching. We introduce a new approach to transform existing 2-D sketches directly into a new kind of sketch-like 3-D model. Finally, we present a novel sketching technique that removes the distinction between 2-D and 3-D altogether. This thesis makes five contributions: point-dragging and curve-drawing techniques for editing sketches; two techniques to help designers bring 2-D sketches to 3-D; and a sketching interface that dissolves the boundaries between 2-D and 3-D representation. The first two contributions of this thesis introduce smooth exploration techniques that work on sketched form composed of strokes, in 2-D or 3-D. First, we present a technique, inspired by classical painting practices, whereby the designer can explore a range of curves with a single stroke. As the user draws near an existing curve, our technique automatically and interactively replaces sections of the old curve with the new one. Second, we present a method to enable smooth exploration of sketched form by point-dragging. The user constructs a high-level "proxy" description that can be used, somewhat like a skeleton, to deform a sketch independent of(cont.) the internal stroke description. Next, we leverage the proxy deformation capability to help the designer move directly from existing 2-D sketches to 3-D models. Our reconstruction techniques generate a novel kind of 3-D model which maintains the appearance and stroke structure of the original 2-D sketch. One technique transforms a single sketch with help from annotations by the designer; the other combines two sketches. Since these interfaces are user-guided, they can operate on ambiguous sketches, relying on the designer to choose an interpretation. Finally, we present an interface to build an even sparser, more suggestive, type of 3-D model, either from existing sketches or from scratch. "Camera planes" provide a complex 3-D scaffolding on which to hang sketches, which can still be drawn as rapidly and freely as before. A sparse set of 2-D sketches placed on planes provides a novel visualization of 3-D form, with enough information present to suggest 3-D shape, but enough missing that the designer can 'read into' the form, seeing multiple possibilities. This unspecified information--this empty space--can spur the designer on to new ideas.by John Alex.Ph.D

The Designosaur and the Furniture Factory: simple software for fast fabrication.

Abstract. We describe two domain oriented design tools that help novice designers design three-dimensional models that they can build using rapid manufacturing equipment. By embedding domain and manufacturing knowledge in the software and providing a sketching interface, novice designers can acquire and practice skills in modeling and manufacturing, without first having to master complicated CAD tools. From sketching to fabrication: simple design tools for making things INTRODUCTION We want to make it easy for ordinary people, especially children, to design and manufacture three-dimensional models using planar components as an entrée to learning to design. We believe that the experience of designing and making things is a powerful vehicle for learning. For many people, designing and making something can be rewarding and engaging, and, we think, can motivate more general learning in science, technology, engineering, and mathematics. Further, we think that in its own right, designing is an intellectual capacity that, once acquired in one domain, can be widely applied. Sadly, many people view design as an innate talent for creativity that they lack. Our project to build lightweight software to engage young people and naïve users in designing and manufacturing simple 3-D models aims to open the door to design and the rich universe of learning that design affords. Three-dimensional physical models are powerful devices that help people see and understand designs. One can hold a physical model in the hand, take it apart, and reassemble it, perhaps in different ways. This ability to interact physically with a model and its parts is important, we think, for thinking about a design; and the experience of designing with 3-D models teaches spatial skills that designers cannot easily acquire through other means such as drawing or computer graphics modeling. Making models in the traditional way demands considerable manual skill and dexterity, for example cutting wood parts with a razor knife. The advent and adoption of rapid prototyping and manufacturing (RPM) machinery has made it possible for ordinary designers, students, and even children, to produce physical artifacts using computational means. Although most RPM hardware is as simple to use as a printer, the software tools that designers use to produce representations for output require a great deal of expertise. To produce a 3-D model designers must create a computer graphic representation. Typically designers do this using powerful general-purpose CAD modeling tools that impose a significant learning curve. Requiring of professional designers this degree of sophistication and expertise may be acceptable; however, the tools bar entry to casual and novice users

Realizing the physics of motile cilia synchronization with driven colloids

Cilia and flagella in biological systems often show large scale cooperative behaviors such as the synchronization of their beats in "metachronal waves". These are beautiful examples of emergent dynamics in biology, and are essential for life, allowing diverse processes from the motility of eukaryotic microorganisms, to nutrient transport and clearance of pathogens from mammalian airways. How these collective states arise is not fully understood, but it is clear that individual cilia interact mechanically,and that a strong and long ranged component of the coupling is mediated by the viscous fluid. We review here the work by ourselves and others aimed at understanding the behavior of hydrodynamically coupled systems, and particularly a set of results that have been obtained both experimentally and theoretically by studying actively driven colloidal systems. In these controlled scenarios, it is possible to selectively test aspects of the living motile cilia, such as the geometrical arrangement, the effects of the driving profile and the distance to no-slip boundaries. We outline and give examples of how it is possible to link model systems to observations on living systems, which can be made on microorganisms, on cell cultures or on tissue sections. This area of research has clear clinical application in the long term, as severe pathologies are associated with compromised cilia function in humans.Comment: 31 pages, to appear in Annual Review of Condensed Matter Physic