Interpreting line drawings of curved objects,”

Abstract In this paper, we study the problem of interpreting line drawings of scenes composed of opaque regular solid objects bounded by piecewise smooth surfaces with no markings or texture on them. It is assumed that the line drawing has been formed by orthographic projection of such a scene under general viewpoint, that the line drawing is error free, and that there are no lines due to shadows or specularities. Our definition implicitly excludes laminae, wires, and the apices of cones. A major component of the interpretation of line drawings is line labelling. By line labelling we mean (a) classification of each image curve as corresponding to either a depth or orientation discontinuity in the scene, and (b) further subclassification of each kind of discontinuity. For a depth discontinuity we determine whether it is a limb-a locus of points on the surface where the line of sight is tangent to the surface-or an occluding edge-a tangent plane discontinuity of the surface. For an orientation discontinuity, we determine whether it corresponds to a convex or concave edge. This paper presents the first mathematically rigorous scheme for labelling line drawings of the class of scenes described. Previous schemes for labelling line drawings of scenes containing curved objects were heuristic, incomplete, and lacked proper mathematical justification. By analyzing the projection of the neighborhoods of different kinds of points on a piecewise smooth surface, we are able to catalog all local labelling possibilities for the different types of junctions in a line drawing. An algorithm is developed which utilizes this catalog to determine all legal labellings of the line drawing. A local minimum complexity rule-at each vertex select those labellings which correspond to the minimum number of faces meeting at the vertex-is used in order to prune highly counter-intuitive interpretations. The labelling scheme was implemented and tested on a number of line drawings. The labellings obtained are few and by and large in accordance with human interpretations

From on-line sketching to 2D and 3D geometry: A fuzzy knowledge based system

The paper describes the development of a fuzzy knowledge based prototype system for conceptual design. This real time system is designed to infer user’s sketching intentions, to segment sketched input and generate corresponding geometric primitives: straight lines, circles, arcs, ellipses, elliptical arcs, and B-spline curves. Topology information (connectivity, unitary constraints and pairwise constraints) is received dynamically from 2D sketched input and primitives. From the 2D topology information, a more accurate 2D geometry can be built up by applying a 2D geometric constraint solver. Subsequently, 3D geometry can be received feature by feature incrementally. Each feature can be recognised by inference knowledge in terms of matching its 2D primitive configurations and connection relationships. The system accepts not only sketched input, working as an automatic design tools, but also accepts user’s interactive input of both 2D primitives and special positional 3D primitives. This makes it easy and friendly to use. The system has been tested with a number of sketched inputs of 2D and 3D geometry

Automatic Structural Scene Digitalization

In this paper, we present an automatic system for the analysis and labeling of structural scenes, floor plan drawings in Computer-aided Design (CAD) format. The proposed system applies a fusion strategy to detect and recognize various components of CAD floor plans, such as walls, doors, windows and other ambiguous assets. Technically, a general rule-based filter parsing method is fist adopted to extract effective information from the original floor plan. Then, an image-processing based recovery method is employed to correct information extracted in the first step. Our proposed method is fully automatic and real-time. Such analysis system provides high accuracy and is also evaluated on a public website that, on average, archives more than ten thousands effective uses per day and reaches a relatively high satisfaction rate.Comment: paper submitted to PloS On

Out of China: Monumental Porcelain

Working collaboratively with teams of local craftsmen in a Chinese manufactory in Jingdezhen, Aylieff has explored how technologies can be adapted to produce appropriate, original and unique contemporary sculptural expressions. Her research has resulted in artworks using an extreme scale not typically associated with porcelain. During a series of residencies in Jingdezhen, Aylieff investigated local traditional ‘blue and white’ ceramic techniques, including glaze application, decorative brushwork and firing methods. This body of research was primarily presented through four exhibitions, two with associated texts. ‘Out of China: Monumental Porcelain’ was an Arts Council-funded solo exhibition of work by Aylieff. During 2008–9, the exhibition toured to three venues: Barn Gallery, West Dean; Gallery Oldham, Manchester; and Lightbox Gallery, Woking. An associated book was published with text by Aylieff and an essay by Professor Emmanuel Cooper. ‘Contemporary Craft Comes to No.10’ was a joint exhibition of work shown at No.10 Downing Street in 2011. Aylieff was one of eight leading makers whose work was selected to be shown. Porcelain City Jingdezhen, a joint exhibition by Felicity Aylieff, Roger Law, Ah Xian, and Takeshi Yasuda was shown at the V&A Museum (2011-12). The exhibition focused on the rich language and history of Chinese porcelain and present-day life in Jingdezhen through contemporary ceramic production. The publication Porcelain City Jingdezhen, which accompanied the exhibition, included an essay by Aylieff: ‘Scooters, Buddhas and water lilies’. ‘China’s White Gold’, an exhibition held at the Fitzwilliam Museum, Cambridge (2012-13), featured eight of Aylieff’s pieces, including four monumental works. Pieces from the exhibitions were acquired by public institutions and for major international collections including the V&A; Shipley Art Gallery; York Museum, and Chatsworth House. During her residency at Jingdezhen, Aylieff was interviewed for the BBC4 television documentary Treasures of Chinese Porcelain (2011)

Experimentation and Representation in Architecture: analyzing one’s own design activity

Architects materialize ideas on physical supports to register their thoughts and to discover new possibilities from hints and suggestions in their own drawings. Uncertainty is inherent to creative processes encouraging the production of different ideas through testing. This research brings to light that the re-examination of artefacts from new points of view allows for the review and generation of design ideas and decisions, capacitating students to make yet new discoveries from what they have done so far. Tacit knowledge aids specific decisions. Student reports become analytical records of their material registers (sketches, physical and virtual models) making it explicit that which is implicit in those artefacts. This apparently confirms previous studies that suggest that knowledge per se not always triggers or controls decisions in design. Many physical as well as perceptive actions actually lead the initial steps and play a crucial role in the whole course of production. Besides serving as external representations, sketches and models provide visual hints that will be checked later, favouring the upcoming of the unexpected, stimulating creativity. The intent here is to point out how these different means of representation and expression contribute in a peculiar manner to the whole process of discovery and solution to problems in architecture. The authors propose here a reflection on the process of design and its uncertainties in its initial phase, concentrating on sketches and real models as experimentations. They consider these means not from a graphic and physical register stand point, but in terms of conception and concepts they embody, as records of students thinking and knowledge. Keywords: Experimentation; Uncertainty; Representation; Design Process; Cognition; Education</p

Exploration through drawings in the conceptual stages of product design

This paper argues that sequences of exploratory drawings - constructed by designer's movements and decisions - trace systematic and logical paths from ideas to designs. This argument has three parts. First, sequences of exploratory sketches produced by product designers, against the same task specification, are analyzed in terms of the cognitive categories of reinterpretation, emergence and abstraction. Second, a computational model is outlined for the process of exploration through drawing and third the model is applied to elucidate the logic in the sequences of exploratory sketches examined earlier

Knowledge practices in design: The role of visual representations as 'epistemic objects'

We use a detailed study of the knowledge work around visual representations to draw attention to the multidimensional nature of `objects'. Objects are variously described in the literatures as relatively stable or in flux; as abstract or concrete; and as used within or across practices. We clarify these dimensions, drawing on and extending the literature on boundary objects, and connecting it with work on epistemic and technical objects. In particular, we highlight the epistemic role of objects, using our observations of knowledge work on an architectural design project to show how, in this setting, visual representations are characterized by a `lack' or incompleteness that precipitates unfolding. The conceptual design of a building involves a wide range of technical, social and aesthetic forms of knowledge that need to be developed and aligned. We explore how visual representations are used, and how these are meaningful to different stakeholders, eliciting their distinct contributions. As the project evolves and the drawings change, new issues and needs for knowledge work arise. These objects have an `unfolding ontology' and are constantly in flux, rather than fully formed. We discuss the implications for wider understandings of objects in organizations and for how knowledge work is achieved in practice