Long hiatus

Last week I was lucky enough to attend SIGGRAPH 2018, in Vancouver. My colleagues and I were presenting on a booth the work we had done, a VR story with a distinctive comic book look. I was also invited to participate to a panel session on demoscene, where I shared some lessons learned while making the 64k intro H – Immersion. The event brought a certain sense of conclusion to this work, aside from filling me with inspiration and motivation to try new things.

It has been a long time since I last posted anything here. For the last two years the majority of my spare time went into making that 64k intro. In fact the last post, “Intersection of a ray and a cone”, was related to it. I was implementing volumetric lighting for the underwater scenes, and wanted to resolve cones of light with ray tracing, before marching inside those cones. LLB and I have talked about the creation process in two making-of articles: “A dive into the making of Immersion”, and “Texturing in a 64kB intro”.

During that time, a lot of new things have happened in the computer graphics community. It has been difficult to keep track of everything. The last topic I started experimenting with is point cloud and mesh capture from photos; I might expend on it here in the future. I also want to experiment with DIY motion capture. Anyway, it’s time to resume posting here.

Unreal Engine experimental scene videos

Since the beginning of 2014, there has been a lot of videos demonstrating the realism that can now be achieved with Unreal Engine 4.

Often, these videos showcase a static scene or even concentrate on a single detail: lighting in an architectural structure, the look of rain hitting the ground, or some wet pebble on the beach.

Physically based rendering, global illumination and screen space reflections seem to manage to trick the brain an get it confused between what is real and what isn’t. Even when some artifacts get salient, like reflections popping in and out or changing with camera orientation, we are quick to forget them and find the image very believable.

Here are some of these videos, by Alexander Dracott, Koola, and Benoît Dereau.

Unreal 4 Lighting Study: Forest Day from Alexander Dracott on Vimeo.

More schlieren photography

I previously mentioned a video showing how schlieren photography could be used to film the propagation of sound.

This video by the Harvard Natural Science Lecture Demonstrations, presents different experiments with schlieren photography. The complete description of the setup used, as well as the explanation of the effect, is also available on the associated web page.

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.

A raytracer under a hundred lines of C++

On his website Kevin Beason presents a Monte Carlo ray tracer written with 99 lines of C++, generating a picture of a Cornell box with global illumination. Beyond the interesting experiment and the fact it can generate a binary of 4kB, I find very valuable the fact there are slides explaining all the code.

Bret Victor – Inventing on Principle

The Toolsmiths, a blog focused on content creation tools for video games, mentioned this enlightening talk by Bret Victor. The first part has some thought provoking ideas for programmers and anyone in a creation process in general. This will certainly strike a chord or two if you’re in the demoscene or in the video game industry.

Looking Around Corners using Femto-Photography

The MIT Media Lab, that I mentioned previously when they published their experiment consisting in filming the very propagation of light, strikes again by using their device to take pictures of objects hidden from the line of sight.

Update: there is now a TED talk presenting femto photography.