The New CGEMS - Preparing the Computer Graphics Educational Materials Source to Meet the Needs of Educators

ACM SIGGRAPH and Eurographics are restarting CGEMS, the Computer Graphics Educational Materials Source, an on-line repository of curricular material for computer graphics education. In this context, the question that we ask ourselves is: ''How can CGEMS best meet the needs of educators''? The aim of this forum is to provide the audience with an idea of the purpose of CGEMS - a source of educational materials for educators by educators - and to give them an opportunity to contribute their views and ideas towards shaping the new CGEMS. Towards this purpose, we have identified a number of issues to resolve, which the panel will put forward to the participants of the forum for discussion

Fast and Memory-Efficient Voronoi Diagram Construction on Triangle Meshes

© 2017 The Author(s) Computer Graphics Forum © 2017 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd. Geodesic based Voronoi diagrams play an important role in many applications of computer graphics. Constructing such Voronoi diagrams usually resorts to exact geodesics. However, exact geodesic computation always consumes lots of time and memory, which has become the bottleneck of constructing geodesic based Voronoi diagrams. In this paper, we propose the window-VTP algorithm, which can effectively reduce redundant computation and save memory. As a result, constructing Voronoi diagrams using the proposed window-VTP algorithm runs 3–8 times faster than Liu et al.'s method [LCT11] , 1.2 times faster than its FWP-MMP variant and more importantly uses 10–70 times less memory than both of them

2005 DOE Computer Graphics Forum Site Survey

The Information Management and Graphics Group supports and develops tools that enhance our ability to access, display, and understand large, complex data sets. Activities include developing visualization software for terascale data exploration; running two video production labs; supporting graphics libraries and tools for end users; maintaining four PowerWalls and assorted other advanced displays; and providing integrated tools for searching, organizing, and browsing scientific data. The Data group supports Defense and Nuclear technologies (D&NT) Directorate. The group's visualization team has developed and maintains two visualization tools: MeshTV and VisIt. These are interactive graphical analysis tools for visualizing and analyzing data on two- and three-dimensional meshes. They also provide movie production support. Researchers in the Center for Applied Scientific Computing (CASC) work on various projects including the development of visualization and data mining techniques for terascale data exploration that are funded by ASC. The researchers also have LDRD projects and collaborations with other lab researchers, academia, and industry

Automatic Generation of Stippling Illustrations from two Photographs

[EN] In this paper we present a software tool that is able to reconstruct the depth field of the objects from two photographs and to obtain a pseudo 3D model. Using this information our system is able to difference background from foreground, and therefore, what are the interesting elements in the photographs and stipple them in different ways.This tool needs almost no user interaction. The user simply has to align both photographs and indicate the level of detail according to the distance. The rest is decided by our software. Whereas a professional illustrator needs more than 20 hours to finish a similar illustration, our software is able to do it in just few seconds.[ES] En este artículo se presenta una herramienta que, a partir de dos fotografías, es capaz de reconstruir la profundidad de los objetos y obtener un modelo 2D y medio. Utilizando dicha información el sistema es capaz de diferenciar qué es fondo y qué un elemento de interés y puntearlos de forma distinta para generar la ilustración final.La herramienta necesita una mínima interacción por parte del usuario para alinear ambas fotografías e indicarle el nivel de detalle a partir de cierta lejanía. El resto es decidido por el software que se encarga de generar la ilustración. Dicha ilustración es generada en pocos segundos por el sistema, mientras que un ilustrador profesional puede tardar aproximadamente 20 horas para realizar el mismo tipo de ilustración.Thanks to Consejería de Innovación y Empresa of the Junta de Andalucía that has partially funded this article throw the project of excelency PE09-TIC-5276.Arroyo, G.; Martín, D.; Luzón, MV. (2012). Automatic Generation of Stippling Illustrations from two Photographs. Virtual Archaeology Review. 3(5):89-92. https://doi.org/10.4995/var.2012.4530OJS899235BARLA, P. et al. (2006): "Interactive hatching and stippling by example". INRIA.DALAL, K. et al. (2006): "A Spectral Approach to NPR Packing". In Proc. of NPAR, ACM, New York, pp. 71-78. http://dx.doi.org/10.1145/1124728.1124741DEUSSEN O. et al. (2000): "Floating points: A method for computing stipple drawings". Computer Graphics Forum 19, pp. 40-51. http://dx.doi.org/10.1111/1467-8659.00396HILLER, S. et al. (2003): "Beyond Stippling - Methods for Distributing Objects on the Plane". Computer Graphics Forum 22, 3, September, pp. 515-522. http://dx.doi.org/10.1111/1467-8659.00699ISENBERG, T. et al. (2005): "Breaking the Pixel Barrier". In Proc. of Cae, Eurographics Association, Aire-la-Ville, Switzerland, pp. 41-48.KIM, S. et al. (2009): "Stippling By Example". In Proc. of NPAR, ACM, New York, pp. 41-50. http://dx.doi.org/10.1145/1572614.1572622MACIEJEWSKI R. et al. (2008): "Measuring Stipple Aesthetics in Hand-Drawn and Computer-Generated Images", IEEE Computer Graphics and Applications, pp. 62-74. http://dx.doi.org/10.1109/MCG.2008.35MOULD D. (2007): "Stipple placement using distance in a weighted graph". In Proc. of Computational Aesthetics in Graphics, no. 3. p. unknown.SCHLECHTWEG S. et al. (2005): "Renderbots: Multi agent systems for direct image generation" Computer Graphics Forum 24, pp 283-290. http://dx.doi.org/10.1111/j.1467-8659.2005.00838.xSECORD A. et al. (2002): "Fast primitive distribution for illustration". In Thirteenth Eurographics Workshop on Rendering, pp. 215-226.SECORD, A. (2002): "Weighted voronoi stippling". In Proc. of NPAR, ACM Press, pp. 37-43. http://dx.doi.org/10.1145/508530.50853

Generation of automatic stippling illustrations from photographs for documenting archaeological pieces

[EN] Hand-made stippling has been used frequently in the process of drawing illustrations for documenting archaeological pieces. This is due to the fact that this technique represents in an efficient way shapes, tones, and textures, by means of distributing dots on the paper. The process of stippling has needed traditionally the ability of an artist, who usually produces the illustration from photographs. In this paper, a program that generates stippling illustrations of high quality is presented. The developed interface makes possible that any user can generate illustrations without the need of artistic abilities. The program is able to work in realtime, allowing the user interacts with the program. We have developed several artistic techniques in high level tasks that allow to improve the final results.[ES] El punteado manual se ha utilizado frecuentemente en el proceso de ilustración para documentar piezas arqueológicas. Esto se debe a que esta técnica es capaz de representar de forma eficiente formas, tonalidades y texturas mediante la distribución de puntos en un papel. Estas ilustraciones requieren las habilidades de un artista, el cual utiliza fotografías para realizarlas. En este artículo se presenta un software que genera ilustraciones punteadas de alta calidad de forma automática. La interfaz desarrollada hace posible que cualquier usuario pueda generar ilustraciones sin la necesidad de habilidades artísticas. El programa trabaja en tiempo real permitiendo al usuario interactuar con el mismo. Hemos implementado varias técnicas empleadas por artistas como simples tareas de alto nivel que mejoran los resultados finales.Authors thank the collaboration of the illustrator Elena Piñar. Thanks to the Ministerio de Educación y Ciencia of Spain for the projects TIN2007-67474-C03-02 and TIN2007-67474-C03-01, which have partially funded this work.Arroyo, G.; Martín, D.; Luzón, MV. (2011). Generation of automatic stippling illustrations from photographs for documenting archaeological pieces. Virtual Archaeology Review. 2(3):59-64. https://doi.org/10.4995/var.2011.4606OJS596423SECORD, A. (2002): "Weighted voronoi stippling". In Proc. of NPAR, ACM Press, pp. 37-43. http://dx.doi.org/10.1145/508530.508537DEUSSEN O. et al. (2000): "Floating points: A method for computing stipple drawings". Computer Graphics Forum 19, pp. 40-51. http://dx.doi.org/10.1111/1467-8659.00396HILLER, S. et al. (2003): "Beyond Stippling - Methods for Distributing Objects on the Plane". Computer Graphics Forum 22, 3, September, pp. 515-522. http://dx.doi.org/10.1111/1467-8659.00699DALAL, K. et al. (2006): "A Spectral Approach to NPR Packing". In Proc. of NPAR, ACM, New York, pp. 71-78. http://dx.doi.org/10.1145/1124728.1124741BARLA, P. et al. (2006): "Interactive hatching and stippling by example". INRIA.SECORD A. et al. (2002): "Fast primitive distribution for illustration". In Thirteenth Eurographics Workshop on Rendering, pp. 215-226.SCHLECHTWEG S. et al. (2005): "Renderbots: Multi agent systems for direct image generation". Computer Graphics Forum 24, 283-290. http://dx.doi.org/10.1111/j.1467-8659.2005.00838.xMOULD D. (2007): "Stipple placement using distance in a weighted graph". In Proc. of Computational Aesthetics in Graphics, no. 3. p. unknown.KIM, S. et al. (2009): "Stippling By Example". In Proc. of NPAR, ACM, New York, pp. 41-50. http://dx.doi.org/10.1145/1572614.1572622ISENBERG, T. et al. (2005): "Breaking the Pixel Barrier". In Proc. of Cae, Eurographics Association, Aire-la-Ville, Switzerland, pp. 41-48.MACIEJEWSKI R. et al. (2008): "Measuring Stipple Aesthetics in Hand-Drawn and Computer-Generated Images", IEEE Computer Graphics and Applications, pp. 62-74. http://dx.doi.org/10.1109/MCG.2008.3

A survey of real-time crowd rendering

In this survey we review, classify and compare existing approaches for real-time crowd rendering. We first overview character animation techniques, as they are highly tied to crowd rendering performance, and then we analyze the state of the art in crowd rendering. We discuss different representations for level-of-detail (LoD) rendering of animated characters, including polygon-based, point-based, and image-based techniques, and review different criteria for runtime LoD selection. Besides LoD approaches, we review classic acceleration schemes, such as frustum culling and occlusion culling, and describe how they can be adapted to handle crowds of animated characters. We also discuss specific acceleration techniques for crowd rendering, such as primitive pseudo-instancing, palette skinning, and dynamic key-pose caching, which benefit from current graphics hardware. We also address other factors affecting performance and realism of crowds such as lighting, shadowing, clothing and variability. Finally we provide an exhaustive comparison of the most relevant approaches in the field.Peer ReviewedPostprint (author's final draft

A Survey of Ocean Simulation and Rendering Techniques in Computer Graphics

This paper presents a survey of ocean simulation and rendering methods in computer graphics. To model and animate the ocean's surface, these methods mainly rely on two main approaches: on the one hand, those which approximate ocean dynamics with parametric, spectral or hybrid models and use empirical laws from oceanographic research. We will see that this type of methods essentially allows the simulation of ocean scenes in the deep water domain, without breaking waves. On the other hand, physically-based methods use Navier-Stokes Equations (NSE) to represent breaking waves and more generally ocean surface near the shore. We also describe ocean rendering methods in computer graphics, with a special interest in the simulation of phenomena such as foam and spray, and light's interaction with the ocean surface