Algorithmic Perception of Vertices in Sketched Drawings of Polyhedral Shapes

In this article, visual perception principles were used to build an artificial perception model aimed at developing an algorithm for detecting junctions in line drawings of polyhedral objects that are vectorized from hand-drawn sketches. The detection is performed in two dimensions (2D), before any 3D model is available and minimal information about the shape depicted by the sketch is used. The goal of this approach is to not only detect junctions in careful sketches created by skilled engineers and designers but also detect junctions when skilled people draw casually to quickly convey rough ideas. Current approaches for extracting junctions from digital images are mostly incomplete, as they simply merge endpoints that are near each other, thus ignoring the fact that different vertices may be represented by different (but close) junctions and that the endpoints of lines that depict edges that share a common vertex may not necessarily be close to each other, particularly in quickly sketched drawings. We describe and validate a new algorithm that uses these perceptual findings to merge tips of line segments into 2D junctions that are assumed to depict 3D vertices

Comments on "what the back of the object looks like: 3D reconstruction from line drawings without hidden lines"

I comment on a paper describing a method for deducing the hidden topology of an object portrayed in a 2D natural line drawing. The principal problem with this paper is that it cannot be considered an advance on (or even an equal of) the state of the art as the approach it describes makes the same limiting assumptions as approaches proposed 10 years ago. There are also important omissions in the review of related wor

Wild camping and the weight of tourism

Wild camping forms a specific social reality within which tourists often claim not to be tourists and within which the capitalist practices central to tourism are messy. Yet, wild camping exemplifies the core idea in tourism: engaging in time during which time is ‘free’. Here the concern is with the ways in which we ‘do’ going camping. We take material interaction with space, place and things as a starting point, via ethnomethodologically informed ethnography, in focusing upon the deployment of mundane, taken-for-granted assumptions, knowledge and practices. We find urban nomads engaged in the clearing, freedom and escape of the outdoors (the lightness), but anchored by the materialities of doing everyday life work, weighted with responsibilities towards nature, things and people

Food tourism and events as tools for social sustainability?

Purpose: Food tourism and events are often prefaced as tools for sustainability within national and intra-national food and agricultural policy contexts. Yet, the realities of enhancing sustainability through food tourism and events are problematic. Sustainability itself is often conceived broadly within policy proclaiming the benefits of food tourism and events, with a need for further deconstruction of the ways each dimension of sustainability – economic, environmental, social and cultural – independently enhances sustainability. The lack of clarity concerning the conceptual utilisation of sustainability works to compromise its value and utilisation for the development of food tourism and events in peripheral areas. In recognition, this paper turns attention to social sustainability within the context of a local food festival, to ask: in what ways is social sustainability enhanced through a local food festival, who benefits from this sustainability, and how? Design: The paper examines the development of a local food festival in a rural coastal community, on Scotland’s west coast. The concept of social capital is utilised to examine the unfolding power relations between committee members, as well as the committee and other social groups. Observant participation undertaken over a 10 month period, between December 2015 and September 2016, renders insights into the ways event planning processes were dependent on the pre-existing accruement of social capital by certain individuals and groups. Findings: Local food festivals have the potential to enhance social sustainability, in offering opportunity to bridge relations across certain diverse groups and foster an environment conducive to cohabitation. Bridging, however, is dependent on preconceived social capital and power relations, which somewhat inhibits social integration for all members of a community. The temporally confined characteristics of events generates difficulties in overcoming the uneven enhancement of social sustainability. Care, thus, needs to be upheld in resolutely claiming enhancement of social sustainability through local food events. Further, broad conceptualisations of ‘community’ need to be challenged during event planning processes; for it is difficult to develop a socially inclusive approach that ensures integration for diverse segments without recognising what constitutes a specific ‘community’. Originality: This paper is situated within the context of a peripheral, yet growing body of literature exploring the potential of events to develop social sustainability. In extending this work, the paper turns attention to the gastronomic - examining the extent to which social sustainability is enhanced through a local food festival, for a rural coastal community – Mallaig, on Scotland’s west coast

A method for reconstructing sketched polyhedral shapes with rounds and fillets

In this paper we present a method for detecting rounds and fillets in engineering sketches and drawings, and automatically generating a 3D model of the corresponding object, with rounds and fillets applied. This method is useful both as a component of computer-aided sketching tools and in determining de- sign intent—although rounds and fillets are common in engineering parts, they often conceal design intent, which is more easily determined from the object’s underlying polyhedral skeleton

The use of modelling techniques in the definition of the UK electricity market

The electricity market in Great Britain has been progressively de-regulated over the last fifteen years. Competition has increased at an exponential rate during this period as new companies have begun operating in the market, which is now arguably the most sophisticated and successful competitive utility market in the world. This success has been achieved only with a degree of complexity. There are now more than a hundred “organisations” that must inter operate, where prior to competition there were only about twenty, operating independently. An organisation in this sense is an identifiable business unit carrying out one of more than a dozen defined roles. Within this complex structure individual organisations need to know their responsibilities and the processes for carrying out market transactions must be defined. (e.g. a customer wishing to change supplier) This requirement has been met by the production of an “industry model” which comprises a series of diagrams, formal definitions and English prose. These are delivered using a combination of a proprietary business modelling tool, a database and textual documents. In this paper the model is explored and an attempt made to classify its components by relating them to the Zachman framework. From this the model’s strengths and weaknesses are postulated. These are then tested by means of a survey of the intended users of the model. Finally, conclusions are drawn about the use of modelling techniques for the definition of a utility industry infrastructure, and recommendations for further research are made

Multi-Modal Geometric Learning for Grasping and Manipulation

This work provides an architecture that incorporates depth and tactile information to create rich and accurate 3D models useful for robotic manipulation tasks. This is accomplished through the use of a 3D convolutional neural network (CNN). Offline, the network is provided with both depth and tactile information and trained to predict the object's geometry, thus filling in regions of occlusion. At runtime, the network is provided a partial view of an object. Tactile information is acquired to augment the captured depth information. The network can then reason about the object's geometry by utilizing both the collected tactile and depth information. We demonstrate that even small amounts of additional tactile information can be incredibly helpful in reasoning about object geometry. This is particularly true when information from depth alone fails to produce an accurate geometric prediction. Our method is benchmarked against and outperforms other visual-tactile approaches to general geometric reasoning. We also provide experimental results comparing grasping success with our method

A fast approach for perceptually-based fitting strokes into elliptical arcs

Fitting elliptical arcs to strokes of an input sketch is discussed. We describe an approach which automatically combines existing algorithms to get a balance of speed and precision. For measuring precision, we introduce fast metrics which are based on perceptual criteria and are tolerant of sketching imperfections. We return a likelihood estimate based on these metrics rather than deterministic yes/no result, in order that the approach can be used in higher-level collaborative-decision recognition flows.1) Ramon y Cajal Scholarship Programme 2) "Pla de Promoció de la Investigació de la Universitat Jaume I", project P1 1B2010-0