Painterly rendering techniques: A state-of-the-art review of current approaches

In this publication we will look at the different methods presented over the past few decades which attempt to recreate digital paintings. While previous surveys concentrate on the broader subject of non-photorealistic rendering, the focus of this paper is firmly placed on painterly rendering techniques. We compare different methods used to produce different output painting styles such as abstract, colour pencil, watercolour, oriental, oil and pastel. Whereas some methods demand a high level of interaction using a skilled artist, others require simple parameters provided by a user with little or no artistic experience. Many methods attempt to provide more automation with the use of varying forms of reference data. This reference data can range from still photographs, video, 3D polygonal meshes or even 3D point clouds. The techniques presented here endeavour to provide tools and styles that are not traditionally available to an artist. Copyright © 2012 John Wiley & Sons, Ltd

Disentangling Factors of Variation by Mixing Them

We propose an approach to learn image representations that consist of disentangled factors of variation without exploiting any manual labeling or data domain knowledge. A factor of variation corresponds to an image attribute that can be discerned consistently across a set of images, such as the pose or color of objects. Our disentangled representation consists of a concatenation of feature chunks, each chunk representing a factor of variation. It supports applications such as transferring attributes from one image to another, by simply mixing and unmixing feature chunks, and classification or retrieval based on one or several attributes, by considering a user-specified subset of feature chunks. We learn our representation without any labeling or knowledge of the data domain, using an autoencoder architecture with two novel training objectives: first, we propose an invariance objective to encourage that encoding of each attribute, and decoding of each chunk, are invariant to changes in other attributes and chunks, respectively; second, we include a classification objective, which ensures that each chunk corresponds to a consistently discernible attribute in the represented image, hence avoiding degenerate feature mappings where some chunks are completely ignored. We demonstrate the effectiveness of our approach on the MNIST, Sprites, and CelebA datasets.Comment: CVPR 201

Combining Procedural and Hand Modeling Techniques for Creating Animated Digital 3D Natural Environments

This thesis focuses on a systematic solution for rendering 3D photorealistic natural environments using Maya\u27s procedural methods and ZBrush. The methods used in this thesis started with comparing two industry specific procedural applications, Vue and Maya\u27s Paint Effects, to determine which is better suited for applying animated procedural effects with the highest level of fidelity and expandability. Generated objects from Paint Effects contained the highest potential through object attributes, texturing and lighting. To optimize results further, compatibility with sculpting programs such as ZBrush are required to sculpt higher levels of detail. The final combination workflow produces results used in the short film Fall. The need for producing these effects is attributed to the growth of the visual effect industry\u27s ability to deliver realistic simulated complexities of nature and as such, the public\u27s insatiable need to see them on screen. Usually, however, the requirements for delivering a photorealistic digital environment fall under tight deadlines due to various phases of the visual effects project being interconnected across multiple production houses, thereby requiring the need for effective methods to deliver a high-end visual presentation. The use of a procedural system, such as an L-system, is often an initial step within a workflow leading toward creating photorealistic vegetation for visual effects environments. Procedure-based systems, such as Maya\u27s Paint Effects, feature robust controls that can generate many natural objects. A balance is thus created between being able to model objects quickly, but with limited detail, and control. Other methods outside this system must be used to achieve higher levels of fidelity through the use of attributes, expressions, lighting and texturing. Utilizing the procedural engine within Maya\u27s Paint Effects allows the beginning stages of modeling a 3D natural environment. ZBrush\u27s manual system approach can further bring the aesthetics to a much finer degree of fidelity. The benefit in leveraging both types of systems results in photorealistic objects that preserve all of the procedural and dynamic forces specified within the Paint Effects procedural engine

Freeform User Interfaces for Graphical Computing

報告番号: 甲15222 ; 学位授与年月日: 2000-03-29 ; 学位の種別: 課程博士 ; 学位の種類: 博士(工学) ; 学位記番号: 博工第4717号 ; 研究科・専攻: 工学系研究科情報工学専

Impressionist Rendering of an Animated Painting

The following thesis documents the development of a non-traditional rendering technique, that of classic impressionist painting, and its use to create an animated three-dimensional painting. Impressionist style painting has an organic feel to it, with brush strokes that remain visible in the dried paint and a light, lively color palette that seeks to capture the light in an image. Reproducing this style in a computer-generated image is no small task. For this project a CG paint method was developed, utilizing Maya Paint Effects and particles. This method was implemented with a script, saving time by automating the process as much as possible. This project was implemented by a group of graduate students. Before settling on the above described solution, many alternative methods were researched and tested. The use of Maya Paint Effects and particles was proven an effective choice for this project because it produced the visual effects desired in a manner that was fairly easily handled by the available equipment. The particle script has been used successfully through three iterations of this project, each time bringing it closer to the original vision

Towards sketch-based exploration of terrain : a feasibility study

CISRG discussion paper ; 1

RENDERING PRINCIPAL DIRECTION CONTOUR LINES WITH ORIENTED TEXTURES

In this paper we explore the use of contour lines in computer graphics as a means of conveying shape to the end-user. Contour lines provide an alternative to traditional realistic rendering styles and may even provide a more appropriate visualization for certain situations. For our images, contour line orientation is established in accordance with principal curvature directions. We present a method for rendering a texture, oriented in the principal curvature direction, across a traditionally-modeled geometric surface that effectively forms suggestive contour lines to enhance the visualization of that surface. We further extend the method to create animated contour textures, wherein lines move across a surface to suggest its shape. We demonstrate how the animation can be made more intuitive and easier to follow through a meaningful generalization of the generated vector space