Dynamic Stylized Shading Primitives

Honorable Mention in RenderingInternational audienceShading appearance in illustrations, comics and graphic novels is designed to convey illumination, material and surface shape characteristics at once. Moreover, shading may vary depending on different configurations of surface distance, lighting, character expressions, timing of the action, to articulate storytelling or draw attention to a part of an object. In this paper, we present a method that imitates such expressive stylized shading techniques in dynamic 3D scenes, and which offers a simple and flexible means for artists to design and tweak the shading appearance and its dynamic behavior. The key contribution of our approach is to seamlessly vary appearance by using a combination of shading primitives that take into account lighting direction, material characteristics and surface features. We demonstrate their flexibility in a number of scenarios: minimal shading, comics or cartoon rendering, glossy and anisotropic material effects; including a variety of dynamic variations based on orientation, timing or depth. Our prototype implementation combines shading primitives with a layered approach and runs in real-time on the GPU

Hybridization of silhouette rendering and pen-and-ink illustration of non-photorealistic rendering technique for 3D object

This study proposes a hybrid of Non-photorealistic Rendering techniques. Nonphotorealistic Rendering (NPR) covers one part in computer graphics that caters towards generating many kinds of 2D digital art style from 3D data, for instance output that looks like painting and drawing. NPR includes the painterly, interpretative, expressive and artistic styles, among others. NPR research deal with different issues such as the stylization that are driven by human perception, the science and art that were brought together and being harmonized with techniques used. Some of approaches used in NPR were discussed such as cartoon rendering, watercolour painting, silhouette rendering, penand- ink illustration and so on. A plan for hybridization of NPR techniques is proposed between silhouette rendering techniques and pen-and-ink illustration for this study. The integration process of these rendering techniques takes on the lighting mapping and also the construction of colour region of the model in order to ensure the pen-and-ink illustration texture can be implemented into the object. The evaluation process is based on the visualization of the image from the hybridization process. Based on findings, the hybridization of NPR technique was able to create interesting results and considered as an alternative in producing new variety of visualization image in NPR

A Process to Create Dynamic Landscape Paintings Using Barycentric Shading with Control Paintings

In this work, we present a process that uses a Barycentric shading method to create dynamic landscape paintings that change based on the time of day. Our process allows for the creation of dynamic paintings for any time of the day using simply a limited number of control paintings. To create a proof of concept, we have used landscape paintings of Edgar Payne, one of the leading landscape painters of the American West. His specific style of painting that blends Impressionism with the style of other painters of the AmericanWest is particularly appropriate for the demonstration of the power of our Barycentric shading method

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

Virtual humans and Photorealism: The effect of photorealism of interactive virtual humans in clinical virtual environment on affective responses

The ability of realistic vs stylized representations of virtual characters to elicit emotions in users has been an open question for researchers and artists alike. We designed and performed a between subjects experiment using a medical virtual reality simulation to study the differences in the emotions aroused in participants while interacting with realistic and stylized virtual characters. The experiment included three conditions each of which presented a different representation of the virtual character namely; photo-realistic, non-photorealistic cartoon-shaded and non-photorealistic charcoal-sketch. The simulation used for the experiment, called the Rapid Response Training System was developed to train nurses to identify symptoms of rapid deterioration in patients. The emotional impact of interacting with the simulation on the participants was measured via both subjective and objective metrics. Quantitative objective measures were gathered using skin Electrodermal Activity (EDA) sensors, and quantitative subjective measures included Differential Emotion Survey (DES IV), Positive and Negative Affect Schedule (PANAS), and the co-presence or social presence questionnaire. The emotional state of the participants was analyzed across four distinct time steps during which the medical condition of the virtual patient deteriorated, and was contrasted to a baseline affective state. The data from the EDA sensors indicated that the mean level of arousal was highest in the charcoal-sketch condition, lowest in the realistic condition, with responses in the cartoon-shaded condition was in the middle. Mean arousal responses also seemed to be consistent in both the cartoon-shaded and charcoal-sketch conditions across all time steps, while the mean arousal response of participants in the realistic condition showed a significant drop from time step 1 through time step 2, corresponding to the deterioration of the virtual patient. Mean scores of participants in the DES survey seems to suggest that participants in the realistic condition elicited a higher emotional response than participants in both non-realistic conditions. Within the non-realistic conditions, participants in the cartoon-shaded condition seemed to elicit a higher emotional response than those in the charcoal-sketch condition

Interactive non-photorealistic rendering

Due to increasing demands of artistic style with Interactive Rate, we propose this review paper as a starting point for any person interested in researching of interactive non-photorealistic rendering. As a simple yet effective means of visual communication, interactive non-photorealistic rendering generates images that are closer to human-drawn than are created by traditional computer graphics techniques with more expressing meaningful visual information. This paper presents taxonomy of interactive non-photorealistic rendering techniques which developed over the past two decades, structured according to the design characteristics and behavior of each technique. Also, it covers the most important algorithms in interactive stylized shade and line drawing, and separately discussing their advantages and disadvantages. The review then concludes with a discussion of the main issues and technical challenges for Interactive Non-Photorealistic Rendering techniques. In addition, this paper discusses the effect of modified phong shading model in order to create toon shading appearance

Computer-assisted animation creation techniques for hair animation and shade, highlight, and shadow

制度:新 ; 報告番号:甲3062号 ; 学位の種類:博士(工学) ; 授与年月日:2010/2/25 ; 早大学位記番号:新532

Bidirectional Appearance Distribution Function for Stylized Shading

We define a new shading tool called a Bidirectional Appearance Distribution Function (BADF) tailored to the direct control of stylized appearance. A BADF can be thought of as defining the appearance of a sphere from all possible illumination directions. Our BADF formulation generalizes and improves upon previous stylized shading techniques by enabling the direct control of shading profiles in screen space, exaggerating surface features in a flexible manner, and letting users control stylized appearance from multiple lighting or viewing directions. This allows users to start from a simple shading behavior, and refine from there towards greater stylization. Our GPU implementation works in real-time, which benefits both editing, and rendering in interactive systems. These features make BADFs an efficient tool for many applications in artistic and scientific illustration domains

Expressive rendering of animated hair

National audienceHair simulation is one of the crucial elements of a character realism in video games as well as animated movies. It is also one of the most challenging because of its complex nature. A simulation model needs to be able to handle hair fibers or wisp interaction while keeping the desired rendering style. During the past few years intensive work has been done in this field. Most of the authors have tried to render and animate hair as realistically as possible. Impressive results have been obtained and computation times have been reduced. Nevertheless this level of realism is not always desired by the animator. Most animated characters are represented with a hair model only composed of a few hair wisps or clumps in other words the individual hair fibers are not even accounted for. Only little work has been done to animate and render non-photorealistic hair for cel-characters1 . The goal of this work is to design an expressive rendering technique for a realistic animation of hair. This project is a part of an ANR research program for a joint industrial project with two production studios: Neomis Animation and BeeLight, two other INRIA project-teams: Bipop and Evasion and a CNRS lab (Institut Jean Le Rond d'Alembert de l'Université Pierre et Marie Curie). The aim of this project is to provide hair rendering and animating tools for movie making. According to the discussions we had with artists from Neomis studio, it appears that an animator will expect realism of hair motion combined with an expressive rendering technique that is dedicated to animated movies

Ink-and-Ray: Bas-Relief Meshes for Adding Global Illumination Effects to Hand-Drawn Characters

We present a new approach for generating global illumination renderings of hand-drawn characters using only a small set of simple annotations. Our system exploits the concept of bas-relief sculptures, making it possible to generate 3D proxies suitable for rendering without requiring side-views or extensive user input. We formulate an optimization process that automatically constructs approximate geometry sufficient to evoke the impression of a consistent 3D shape. The resulting renders provide the richer stylization capabilities of 3D global illumination while still retaining the 2D handdrawn look-and-feel. We demonstrate our approach on a varied set of handdrawn images and animations, showing that even in comparison to ground truth renderings of full 3D objects, our bas-relief approximation is able to produce convincing global illumination effects, including self-shadowing, glossy reflections, and diffuse color bleeding