Perceptually Uniform Construction of Illustrative Textures

Illustrative textures, such as stippling or hatching, were predominantly used as an alternative to conventional Phong rendering. Recently, the potential of encoding information on surfaces or maps using different densities has also been recognized. This has the significant advantage that additional color can be used as another visual channel and the illustrative textures can then be overlaid. Effectively, it is thus possible to display multiple information, such as two different scalar fields on surfaces simultaneously. In previous work, these textures were manually generated and the choice of density was unempirically determined. Here, we first want to determine and understand the perceptual space of illustrative textures. We chose a succession of simplices with increasing dimensions as primitives for our textures: Dots, lines, and triangles. Thus, we explore the texture types of stippling, hatching, and triangles. We create a range of textures by sampling the density space uniformly. Then, we conduct three perceptual studies in which the participants performed pairwise comparisons for each texture type. We use multidimensional scaling (MDS) to analyze the perceptual spaces per category. The perception of stippling and triangles seems relatively similar. Both are adequately described by a 1D manifold in 2D space. The perceptual space of hatching consists of two main clusters: Crosshatched textures, and textures with only one hatching direction. However, the perception of hatching textures with only one hatching direction is similar to the perception of stippling and triangles. Based on our findings, we construct perceptually uniform illustrative textures. Afterwards, we provide concrete application examples for the constructed textures.Comment: 11 pages, 15 figures, to be published in IEEE Transactions on Visualization and Computer Graphic

Printing and Book Production: Prospectus of Courses 1938-39

Courses and timetables for the College of Technology, Bolton Street, Dublin 1

Printing and Book Production: Prospectus of Courses Session 1937-38

Courses and timetables for the College of Technology, Bolton Street, Dublin 1

A critical survey of the materials and techniques of Charles Henry Sims RA (1873-1928) with special reference to egg tempera media and works of art on paper

This thesis collates and provides new knowledge about the working practices and dissemination of materials and techniques of a leading Edwardian painter. Charles Sims RA (1873-1928) represents a neglected body of British artists who were responding to and assimilating certain new tendencies within early modernism yet at the same time were conscious and respectful of traditional practices and training methods. The study makes consistent reference to the extensive studio archive at Northumbria University whose existence has provided a unique opportunity to map Sims’ own informal working notes and observations, against the retrospective account Picture Making (1934) by his son, and instrumental and technical analyses performed on some works. The significance of this specific period in relation to the development of new materials and techniques, and the role instruction manuals and teaching played in developing Sims' stylistic and at times thematic approaches to practice are also discussed. Of particular interest are those which focus on drawing, watercolour and egg tempera techniques, media which perfectly suited Sims' temperament and arguably featured in and formed his best works. The thesis also aims to compare Sims' working practices with those of his better known contemporaries such as Augustus John, Philip Wilson Steer, William Orpen (all from the Slade) as well as members of the Tempera Revival movement. by crossreferencing reports held in national and international collections with hitherto unseen material. As a consequence the research will have a much wider application beyond the field of conservation, and will illuminate early 20th century artistic inheritance and intent

On the maintained significance of botanical illustration in modern plant identification guides

This project began over 2.5 years ago when I, an artist by hobby, contacted Dr. Joey Shaw, the director of the Herbarium at the University of Tennessee Chattanooga, with a request to sketch from specimens in the UCHT collection. Dr. Shaw, fortuitously in need of an illustrator, prompted me with the opportunity to collaborate with him in the creation of illustrations for the second edition of the Guide to the Vascular Plants of Tennessee. From here, this project has grown as we have attempted to determine the most effective way to illustrate the guide, our questions manifesting in a myriad of interdisciplinary investigations, from an exploration on the historical development of botanical illustration, to a survey of the use of figures in modern botanical keys, and ultimately to our practical exercise in drafting illustrations for later inclusion into the Guide to the Vascular Plants of Tennessee. This document represents the products of these variable investigations, strung together by prevalent themes of convention, technology, and communication, to lend credence to the maintained significance of botanical illustration in the modern world of botanical science

On the role of cold and warm sectors of synoptic systems in the atmospheric response to Sea Surface Temperature anomalies in aquaplanet simulations

Two sets of novel techniques are developed to study the atmospheric response to an SST anomaly. Firstly, a model surgery method (“Masking Technique”) is developed to be incorporated into a General Circulation Model (GCM), in which an interactive “mask” is used to systematically isolate and study the air-sea interaction over the warm and cold sectors of extratropical cyclones independently to each other. This method is applied to an idealised aquaplanet GCM (AFES) with a 150 km resolution forced with a fixed SST anomaly comparable to a tightening of the SST gradient over a Western Boundary Current. Results show that the atmospheric response via the cold sector (CSA) alone was able to reproduce the response when both cold and warm sectors interact with the SST anomaly. The same experiment with an identical set-up but with increased resolution (50km grid size) was performed. An opposite result was produced where the warm sector response (WSA) was more successful in reproducing the full response, suggesting that Low Resolution (LR) models often used in climate simulations suppress the processes occurring in the warm sector. In both LR and HR experiments, the Pressure Adjustment Mechanism was observed in the CSA case and not in the WSA case. However, in the HR model, response in the WSA showed regions of high baroclinicity and Eddy Kinetic Energy as well as strong upper-level response comparable to the full response, highlighting the role of the warm sector in restoring the baroclinicity in the storm track regions, as well as its ability to perturb the upper troposphere. This is in contrast to the cold sector response in which interaction was largely confined to shallow layers of the atmosphere. Secondly, a new frontal tracking method is developed that identifies atmospheric fronts objectively from gridded datasets. This diagnostic is applied to the aquaplanet simulation previously described to study the interaction between fronts and the SST anomaly. Applying the tracking method on the aquaplanet with the prescribed SST anomaly showed an increase in the frequency of fronts near the centre of the tightened SST gradient and a poleward shift of the trajectory of the fronts. Combining the tracking method and composite analysis showed that, on average, transverse circulation of individual fronts was dampened by crossing the SST anomaly.Open Acces

Printmaking: a phenomenological art

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