The Computer Graphics Forum 2014 Cover Image has been selected by the CGF editorial board. We thanks all people who submitted this year, and hope that they will participate to the next year contest.

Winner of the Computer Graphics Forum 2014 Cover Image Contest

Marco Ament, Filip Sadlo and Daniel Weiskopf

University of Stuttgart

This image presents a rendering of a supernova data set obtained with our ambient volume scattering technique, which was recently published at IEEE SciVis 2013 and received an Honorable Mention award. Our method approximates global illumination in participating media including scattering and soft shadows at interactive frame rates, using preintegrated light transport.

Compared to traditional volume rendering, our technique provides improved perception of spatial depth and relative size of volumetric features. Furthermore, our method not only provides interactive exploration but also avoids the difficult control of full global illumination. In the present example of astrophysical visualization, we are able to depict the global structure of the supernova as well as its filaments of different scales.

Second place:

Jan Novák (1), Derek Nowrouzezahrai (2), Carsten Dachsbacher (1) and Wojciech Jarosz (3)

(1) Karlsruhe Institute of Technology
(2) Université de Montréal
(3) Disney Research Zürich

This image shows two glasses with anisotropically scattering media---orange and grapefruit juice---that were rendered using a combination of density estimation and many-light approaches as proposed in the paper "Virtual Ray Lights for Rendering Scenes with Participating Media" by Jan Novak, Derek Nowrouzezahrai, Carsten Dachsbacher, and Wojciech Jarosz, published at SIGGRAPH 2012.

We employed progressive photon mapping for surface illumination, progressive photon beams for single scattering, and virtual ray lights for simulating multiple scattering inside the juice. While single scattering captures most of the visually interesting features, e.g. the volumetric caustic at the bottom of the glass, multiple scattering provides the characteristic soft saturated look.

The photon beams and the virtual ray lights are created from line segments of photon paths, that are emitted from light sources. These segments are then connected to camera rays either by density estimation, or next event estimation. Despite being conceptually different, both techniques complement each other well, providing fast previews, high-quality results, as well as convergence to ground truth.

The geometry was modeled by Wojciech Jarosz; the scene was laid out and rendered by Jan Novak.

Third place:

Sho Ikeda, Shin Watanabe and Kazufumi Kaneda

Hiroshima university

Iridescent Caustics

This image depicts indirect illumination generated by five silicon rings coated with a thin film.
Each ring has a SiO2 film with different thickness and generates different colors due to the interference of light.

The image was rendered by a physically based spectral renderer under the global illumination environment.
The rendering technique will be presented in the International Workshop on Advanced Image Technology (IWAIT) 2014:
"Physically Based Spectral Rendering of Optical Phenomena Caused by Multilayer Films under Global Illumination Environment."
To visualize the indirect illumination component, we dimmed the direct illumination,
and to get a RGB image from a spectral image, we used a RGB conversion with color matching functions.