A workflow for designing stylized shading effects

In this report, we describe a workflow for designing stylized shading effects on a 3D object, targeted at technical artists. Shading design, the process of making the illumination of an object in a 3D scene match an artist vision, is usually a time-consuming task because of the complex interactions between materials, geometry, and lighting environment. Physically based methods tend to provide an intuitive and coherent workflow for artists, but they are of limited use in the context of non-photorealistic shading styles. On the other hand, existing stylized shading techniques are either too specialized or require considerable hand-tuning of unintuitive parameters to give a satisfactory result. Our contribution is to separate the design process of individual shading effects in three independent stages: control of its global behavior on the object, addition of procedural details, and colorization. Inspired by the formulation of existing shading models, we expose different shading behaviors to the artist through parametrizations, which have a meaningful visual interpretation. Multiple shading effects can then be composited to obtain complex dynamic appearances. The proposed workflow is fully interactive, with real-time feedback, and allows the intuitive exploration of stylized shading effects, while keeping coherence under varying viewpoints and light configurations. Furthermore, our method makes use of the deferred shading technique, making it easily integrable in existing rendering pipelines.Dans ce rapport, nous décrivons un outil de création de modèles d'illumination adapté à la stylisation de scènes 3D. Contrairement aux modèles d'illumination photoréalistes, qui suivent des contraintes physiques, les modèles d'illumination stylisés répondent à des contraintes artistiques, souvent inspirées de la représentation de la lumière en illustration. Pour cela, la conception de ces modèles stylisés est souvent complexe et coûteuse en temps. De plus, ils doivent produire un résultat cohérent sous une multitude d'angles de vue et d'éclairages. Nous proposons une méthode qui facilite la création d'effets d'illumination stylisés, en décomposant le processus en trois parties indépendantes: contrôle du comportement global de l'illumination, ajout de détails procéduraux, et colorisation.Différents comportements d'illumination sont accessibles à travers des paramétrisations, qui ont une interprétation visuelle, et qui peuvent être combinées pour obtenir des apparences plus complexes. La méthode proposée est interactive, et permet l'exploration efficace de modèles d'illumination stylisés. La méthode est implémentée avec la technique de deferred shading, ce qui la rend facilement utilisable dans des pipelines de rendu existants

Automatic Recognition of African Bust using Modified Principal Component Analysis (MPCA)

This study identified and analysed the pattern recognition features of African bust. It also developed and evaluated a Modified Principal Component Analysis (MPCA) for recognizing those features. This was with a view to providing information on the developed MPCA for a robust approach to recognition of African bust.The developed MPCA used varying number of eigenvectors in creating the bust space. The characteristics of the bust in terms of facial dimension, types of marks, structure of facial components such as the eye, mouth, chin etc were analysed for identification. The bust images were resized for proper reshaping and cropped to adjust their backgrounds using the Microsoft Office Picture Manager. The system code was developed and run on the Matrix Laboratory software (MatLab7.0).The use of varying values of eigenvectors has proven positive result as far as the system evaluation was concerned. For instance, a sensitivity test carried out revealed that thirteen out of seventeen bust’s images were recognized by selecting only vectors of highest eigenvalues while all the test images were recognized with the inclusion of some vectors of low energy level. That is, the modification made to the Conventional PCA (i.e. Eigenface Algorithm) gave rise an increment of about twenty five percent (25%) as far as recognizing the test images was concerned.The study concluded that the Modification made to the conventional PCA has shown very good performance as far as the parameters involved were concerned. The performance of the MPCA was justified by the identification of all the test images, that is, the MPCA proved more efficient than the Conventional PCA technique especially for the recognition of features of the African busts. Keywords: Eigenvectors, Bust recognition, Modified Principal Component Analysis Technique (MPCA), African Bust

3D digital relief generation.

This thesis investigates a framework for generating reliefs. Relief is a special kind of sculptured artwork consisting of shapes carved on a surface so as to stand out from the surrounding background. Traditional relief creation is done by hand and is therefore a laborious process. In addition, hand-made reliefs are hard to modify. Contrasted with this, digital relief can offer more flexibility as well as a less laborious alternative and can be easily adjusted. This thesis reviews existing work and offers a framework to tackle the problem of generating three types of reliefs: bas reliefs, high reliefs and sunken reliefs. Considerably enhanced by incorporating gradient operations, an efficient bas relief generation method has been proposed, based on 2D images. An improvement of bas relief and high relief generation method based on 3D models has been provided as well, that employs mesh representation to process the model. This thesis is innovative in describing and evaluating sunken relief generation techniques. Two types of sunken reliefs have been generated: one is created with pure engraved lines, and the other is generated with smooth height transition between lines. The latter one is more complex to implement, and includes three elements: a line drawing image provides a input for contour lines; a rendered Lambertian image shares the same light direction of the relief and sets the visual cues and a depth image conveys the height information. These three elements have been combined to generate final sunken reliefs. It is the first time in computer graphics that a method for digital sunken relief generation has been proposed. The main contribution of this thesis is to have proposed a systematic framework to generate all three types of reliefs. Results of this work can potentially provide references for craftsman, and this work could be beneficial for relief creation in the fields of both entertainment and manufacturing

Ultrasound—Re:viewing Bodies

A medical evaluation of physical impairment imposes the additional burden of “labeling” the patient with the condition. The binary nature of the normal versus abnormal label emphasizes difference and can lead to trauma. Understanding differences, however, can lead to the generation of new forms and thus, more sensitive differentiation and representation. Tension is created by exploring different bodily forms—a dialectic between form and essence. I am designing a space that visualizes and illuminates difference as a source of trauma and amplifying the tension by comparing figures that represent varying degrees of normalcy. This forms a critique of idealized form and creates a context for people unaffected by this type of trauma to reflect on possible realities outside of their assumptions of normality

Shading with Painterly Filtered Layers: A Process to Obtain Painterly Portraits

In this thesis, I study how color data from different styles of paintings can be extracted from photography with the end result maintaining the artistic integrity of the art style and having the look and feel of skin. My inspiration for this work came from the impasto style portraitures of painters such as Rembrandt and Greg Cartmell. I analyzed and studied the important visual characteristics of both Rembrandt’s and Cartmell’s styles of painting.These include how the artist develops shadow and shading, creates the illusion of subsurface scattering, and applies color to the canvas, which will be used as references to help develop the final renders in computer graphics. I also examined how color information can be extracted from portrait photography in order to gather accurate dark, medium, and light skin shades. Based on this analysis, I have developed a process for creating portrait paintings from 3D facial models. My process consists of four stages: (1) Modeling a 3D portrait of the subject, (2) data collection by photographing the subjects, (3) Barycentric shader development using photographs, and (4) Compositing with filtered layers. My contributions has been in stages (3) and (4) as follows: Development of an impasto-style Barycentric shader by extracting color information from gathered photographic images. This shader can result in realistic looking skin rendering. Development of a compositing technique that involves filtering layers of images that correspond to different effects such as diffuse, specular and ambient. To demonstrate proof-of-concept, I have created a few animations of the impasto style portrait painting for a single subject. For these animations, I have also sculpted high polygon count 3D model of the torso and head of my subject. Using my shading and compositing techniques, I have created rigid body animations that demonstrate the power of my techniques to obtain impasto style portraiture during animation under different lighting conditions

InSEA European Regional Congress: Tales of art and curiosity

Proceedings volume from the International Society for Education through Art (InSEA) European Regional Congress

The mobility of facts

This thesis investigates the reductive abstraction of the digital and the physical immediacy of the sculptural, commonly perceived as an antagonistic relationship. Through a practical dialogue between virtual and tangible media I ask: what can digital technology tell us about the nature of sculpture as a contemporary art form? My practical experiments adapted a flexible methodology of digitising found objects through 3D scanning, digital modelling and CAD drawing; transforming them via a mix of contemporary software; and then reconstituting them as physical objects through 3D printing, analogue casting and hand tooling. This approach allowed the characteristics of tangible materials and processes to feedback against the affordances and constraints of digital operations. The research demonstrates that this feedback occurs in ways that are generative rather than antagonistic. By strategically deploying digital media to develop autonomous sculpture, I reconnect haptic perception with critical reflection upon that experience driven by analyses of current understandings of how digital mediation works. The first part of the written component involves a theoretical enquiry into the means applied to production. Drawing upon recent art historical, anthropological and philosophical arguments, I question tropes of digital immateriality, computational thinking, and the ‘fixed facticity’ of sculpture. The second part provides an account of new insights brought to light by the struggle to realise these artworks in physical matter and arrive at a cogent understanding of what is made present as a consequence of digital mediation in the finished works. My research shows how digital technology can emphasise rather than undermine what is particular to sculpture. It emerges that sculpture must rely on a tension between its tangible form and abstract mediation if it is to suspend reification. On the other hand, these sculptures problematize the tendency of digital technologies to efface aspects of their very real materiality. They could be seen as paradigmatic of our contradictory relations to objects in a world where the limits of what we think of as reality have become less clear. This research proposes that it is the sensuousness of the embodied encounter that makes the abstract anomalies of digital operations so incongruous. By calling attention to themselves as made things – digital artifices – the artworks produced in this research generate moments of ambivalence that oscillate between presentation and representation, cognition and recognition, when consciousness might take itself as its object. As concrete abstractions, they encapsulate how digital mediation alters the material fabric of the world

Making Up the 3D Body: Designing for Artistic and Serendipitous Interaction in Modelling Digital Human Figures

Making Up the 3D Body: Designing for Artistic and Serendipitous Interaction in Modelling Digital Human Figures details the process of developing a new software tool for digital artistic exploration. Previously available software for modelling mesh-based 3D human figures restricts user output based on normative assumptions about the form that a body might take, particularly in terms of gender, race, and disability status, which are reinforced by ubiquitous use of range-limited sliders mapped to singular high-level design parameters. CreatorCustom, the software tool created during this research, is designed to foreground an exploratory and open-ended approach to modelling 3D human bodies, treating the digital body as a sculptural landscape rather than a pre-supposed form for rote technical representation. Building on the foundation of prior research into serendipity in Human-Computer Interaction, creativity support tools, 3D modelling systems for users at various levels of proficiency, and usability, among others, this research takes the form of two qualitative studies and an autoethnography of the author’s artistic practice. The first study explores the practices of six queer artists working with the body and the language, materials, and actions they use in their practice, as described in interview and structured material practice sessions, which were then applied toward the design of the software tool. The second study deals with the usability, creativity support, and bodily implications and outcomes of the software tool when used by thirteen artist participants in a workshop setting. Reflecting on the relationship between affect and usability, and surprises and the unexpected in creative technology and artistic practice, these strands are brought together in an analysis and discussion of the author’s experience of using the software tool to create her own artistic work dealing with gender and sexuality

The Stone Lab: Decoding Shikahogh Khachkars

"The Stone lab: Decoding Shikahogh Khachkars" is an MPhil by design, seeking to describe the role of Khachkar in formation of Armenian national identity through studies of the stone masonry and the notion of a territory, which in this case is represented with the Shikahogh village (Figs. 1 and 2). Although much study has been done on Khachkars in general, no prior research has been conducted on the historic cradle of Khachkars that is Shikahogh. The Stone lab aims to discover and interpret the stories of Shikahogh unknown Khachkars. Therefore the hybrid approach of experimental archaeology and digital reconstruction have been employed at the Shikahogh lab to unveil the hidden inscriptions of these Khachkars as well as to narrate the functions and technological processes behind their creation. This research portrays the driving factors of belonging and identify preservation underneath the context of Khachkar and Petroglyphic heritage of Armenia