Geometry-based shading for shape depiction Enhancement,

Recent works on Non-Photorealistic Rendering (NPR) show that object shape enhancement requires sophisticated effects such as: surface details detection and stylized shading. To date, some rendering techniques have been proposed to overcome this issue, but most of which are limited to correlate shape enhancement functionalities to surface feature variations. Therefore, this problem still persists especially in NPR. This paper is an attempt to address this problem by presenting a new approach for enhancing shape depiction of 3D objects in NPR. We first introduce a tweakable shape descriptor that offers versatile func- tionalities for describing the salient features of 3D objects. Then to enhance the classical shading models, we propose a new technique called Geometry-based Shading. This tech- nique controls reflected lighting intensities based on local geometry. Our approach works without any constraint on the choice of material or illumination. We demonstrate results obtained with Blinn-Phong shading, Gooch shading, and cartoon shading. These results prove that our approach produces more satisfying results compared with the results of pre- vious shape depiction techniques. Finally, our approach runs on modern graphics hardware in real time, which works efficiently with interactive 3D visualization

Interactive toon shading using mesh smoothing

Toon shading mimics the style of few colour bands and hence offers an effective way to convey the cartoon-style rendering. Despite an increasing amount of research on toon shading, little research has been reported on generation of toon shading style with more simplicity. In this paper, we present a method to create a simplified form of toon shading using mesh smoothing from 3D objects. The proposed method exploits the Laplacian smoothing to emphasise the simplicity of 3D objects. Motivated by simplified form of Phong lighting model, we create non-photorealistic style capable of enhancing the cartoonish appearance. An enhanced toon shading algorithm is applied on the simple 3D objects in order to convey more simple visual cues of tone. The experimental result reveals the ability of proposed method to produce more cartoonish simplistic effects

Semiotična sporočilnost kartografskih znakov na starih zemljevidih

This study analyzed selected cartographic symbols on old maps depicting the territory of Slovenia from the sixteenth to nineteenth century. A semiotic approach was applied to establish connections between cartographic symbols on old maps and the characteristics of society at the time the maps were created. This semiotic approach was used to discuss the impact of the interpretation of four symbolic cartographic elements, their iconic basis, and the reading of the five maps analyzed. Cartographic symbols changed in line with the development of cartography at the time, as well as society. The depictions of settlements were first stylistic and then geometric. Relief depictions were first stylized and then shown through plastic or spatial methods. Cartographic symbols gradually changed into symbolic signs (in the semiotic sense), including the quality of the map display, as a result of developments and the demands of changing society.Analizirali smo izbrane kartografske znake na starih zemljevidih ozemlja Slovenije od 16. do 19. stoletja. S semiotičnim pristopom smo ugotavljali povezave med kartografskimi znaki na starih zemljevidih in značilnostmi družbe v času nastanka zemljevidov. S semiotičnim pristopom smo obravnavali vpliv interpretacije štirih simbolnih kartografskih elementov, njihove ikonske podlage in družbenega koncepta na branje analiziranih petih zemljevidov. Kartografski znaki so se spreminjali glede na razvoj takratne kartografske stroke in družbe. Upodobitve naselij so bile najprej stilizirane, nato geometrijske. Reliefne upodobitve so bile najprej stilizirane in nato prikazane s plastičnim ali prostorskim načinom prikaza. Kartografski znaki so se postopoma spreminjali v simbolne znake, vključno s kakovostjo prikaza zemljevida, kot posledica razvoja in zahtev spreminjajoče družbe

Improving Shape Depiction under Arbitrary Rendering

International audienceBased on the observation that shading conveys shape information through intensity gradients, we present a new technique called Radiance Scaling that modifies the classical shading equations to offer versatile shape depiction functionalities. It works by scaling reflected light intensities depending on both surface curvature and material characteristics. As a result, diffuse shading or highlight variations become correlated to surface feature variations, enhancing concavities and convexities. The first advantage of such an approach is that it produces satisfying results with any kind of material for direct and global illumination: we demonstrate results obtained with Phong and Ashikmin-Shirley BRDFs, Cartoon shading, sub-Lambertian materials, perfectly reflective or refractive objects. Another advantage is that there is no restriction to the choice of lighting environment: it works with a single light, area lights, and inter-reflections. Third, it may be adapted to enhance surface shape through the use of precomputed radiance data such as Ambient Occlusion, Prefiltered Environment Maps or Lit Spheres. Finally, our approach works in real-time on modern graphics hardware making it suitable for any interactive 3D visualization

Real-Time Stylized Rendering for Large-Scale 3D Scenes

While modern digital entertainment has seen a major shift toward photorealism in animation, there is still significant demand for stylized rendering tools. Stylized, or non-photorealistic rendering (NPR), applications generally sacrifice physical accuracy for artistic or functional visual output. Oftentimes, NPR applications focus on extracting specific features from a 3D environment and highlighting them in a unique manner. One application of interest involves recreating 2D hand-drawn art styles in a 3D-modeled environment. This task poses challenges in the form of spatial coherence, feature extraction, and stroke line rendering. Previous research on this topic has also struggled to overcome specific performance bottlenecks, which have limited use of this technology in real-time applications. Specifically, many stylized rendering techniques have difficulty operating on large-scale scenes, such as open-world terrain environments. In this paper, we describe various novel rendering techniques for mimicking hand-drawn art styles in a large-scale 3D environment, including modifications to existing methods for stroke rendering and hatch-line texturing. Our system focuses on providing various complex styles while maintaining real-time performance, to maximize user-interactability. Our results demonstrate improved performance over existing real-time methods, and offer a few unique style options for users, though the system still suffers from some visual inconsistencies

Perceptual, semantic and affective dimensions of experience of abstract and representational paintings

In this study the difference between representational and abstract paintings in judgments on perceptual, semantic and affective dimensions was investigated. Two groups of participants judged the sets of representational and abstract paintings on three groups of dimensions: perceptual (Form, Color, Space and Complexity), semantic (Illusion-Construction of Reality, Expression, Ideology and Decoration), and affective (Hedonic Tone, Arousal, Relaxation and Regularity). The results have shown that representational paintings have higher judgments on the perceptual dimensions of Form and Complexity, the semantic dimension of the Illusion of Reality (the opposite pole of the Construction of Reality), and the affective dimension of Regularity. On the other hand, abstract paintings have higher judgments on the perceptual dimension of Color, the semantic dimensions of Construction of Reality (the opposite pole of the Illusion of Reality) and Expression, and the affective dimension Arousal. A discriminant analysis indicated that all three sets of dimensions are relatively good predictors of the classification of representational and abstract paintings (61-100%). The results suggest that the subjective categorization of paintings is generally based on the recognizability of pictorial content (representational vs. abstract), but some formal or stylistic properties play a role in the categorization, as well: some expressionistic representational paintings were classified in an abstract category, and some geometrically abstract paintings were classified as representational