Invitation to Revision party 2014

Revision is a big demoparty held each year at Easter, in Saarbrücken, Germany. Whenever possible, it is a custom in the demoscene to release a production dedicated to officially announce upcoming parties: an invitation.

Last weekend at the Ultimate Meeting, the invitation to Revision 2014 was presented. The quality of invitations can vary wildly, from rushed and uninspired to works of art (Kings of the playground or You Should are two examples that come to mind); this new invitation is rather on the higher end of the spectrum. Aiming for epic feeling, and nailing it, it imagines a time when the mostly unheard off sub culture has become a dominant one and the reason for a major Super Bowl like event in a Tron like set.

Enjoy it and its dry wit jokes. :)

The cinematography of The Incredibles

On his blog, director Ron Doucet presents a thorough analysis of the visual constructions in the Pixar animation film, The Incredibles. The articles include breakdowns of complete scenes in term of visual components. It is a great read on how the picture can be designed to support the storytelling.

Cliff Strike

Base jumper Subterminallyill posted on his Vimeo page a very impressive, immersive (seemingly a helmet mounted GoPro) slow motion footage of his last jump off a cliff, which as it happens didn’t go well at all. As the seconds slowly pass by, the moment almost feels like a soft, skimming interaction. But as soon as the actual speed is revealed, it shows a brutal, violent accident happening in a split second.

Cliff Strike 11/24/2013 from Subterminallyill on Vimeo.

First-photon imaging

The compressive sensing blog Nuit-Blanche reports this publication: First-photon imaging. The technique allows to capture depth and (limited) reflectivity information using only a small number of photons (virtually in the dark).

Abstract:

Imagers that use their own illumination can capture 3D structure and reflectivity information. With photon-counting detectors, images can be acquired at extremely low photon fluxes. To suppress the Poisson noise inherent in low-flux operation, such imagers typically require hundreds of detected photons per pixel for accurate range and reflectivity determination. We introduce a low-flux imaging technique, called first-photon imaging, which is a computational imager that exploits spatial correlations found in real-world scenes and the physics of low-flux measurements. Our technique recovers 3D structure and reflectivity from the first detected photon at each pixel. We demonstrate simultaneous acquisition of sub-pulse duration range and 4-bit reflectivity information in the presence of high background noise. First-photon imaging may be of considerable value to both microscopy and remote sensing.

John Carmack on physically based rendering at QuakeCon 2013

In this (slightly over) one hour talk, 1½ hour including Q&A, John Carmack walks through the physics of light, the early days of rendering, the current state of the art, and the direction it is headed at. In short: until we can afford path tracing, we’re approximating it.

The rendering tools in the film industry

Here is a list of articles published by fxguide, giving fascinating insights into the tools used by the film industry in terms of rendering.

  • Ben Snow: the evolution of ILM’s lighting tools (January 2011)
    A presentation of the evolution of the technology and tools used at Industrial Light and Magic, over the course of the years and movies, from the mid-90s to nowadays.
  • Monsters University: rendering physically based monsters (June 2013)
  • The Art of Rendering (April 2012)
    A description of the different techniques used in high end rendering and the major engines.
  • The State of Rendering (July 2013): part 1, part 2
    A lengthy overview of the state of the art in high end rendering, comparing the different tools and rendering solutions available, their approach and design choices, strengths and weaknesses as well as the consequences in terms of quality, scalability and render time.

(Brace yourselves for the massive tag list hereafter.)

Simple light setup for outdoor environments

On his website, Iñigo Quilez (known for a wide range of notable contributions at RGBA, BeautyPi and Pixar; talk about an over-achiever! but I digress already), recently described the light setup he often uses for outdoor environments.

Capture of his technique in action

From the article:

This articles describes the lighting rig I use when doing such tiny computer graphics experiments with landscapes. It’s basically made of 3 or 4 directional lights, one shadow, some (fake or screen space) ambient occlusion, and a fog layer. These few elements tend to behave nicely and even look fotoreal-ish if balanced properly.

Setting up lights is not an easy task, so this article is a very welcomed insight. I especially like the trick of using an opposite directional light to fake global illumination. I also very much agree on using actual fill lights. Constant ambient alone is not enough, as you lose any sense of volume in the shadowed parts.

I am not too fond of the shadow penumbra trick though, which he described previously already. I must admit it indeed gives a warm look, but it doesn’t make any physical sense. So I suspect this should rather belong to the tone mapping part of the rendering, just like the square root he used to apply to the diffuse fall-off really was really working around the lack of gamma correction.

The recommendation to keep albedo near 0.2 is an interesting one. Indeed, your typical rock and grass albedo is nowhere near the albedo of snow (a quick look at Wikipedia gives this comparison chart). But if it is stored in a texture in a typical rendering pipeline, the question of precision lingers. I wonder how big game studios typically address this.