Relativistic and non euclidean space rendering

The Portal series built a full game concept out of non euclidean spaces. Besides being great games, I think it is fascinating how true the tagline “Now you’re thinking with portals” is.

Here are two interesting experiments putting the person in different spaces than we are used to due to real world conditions. This video by Varun Ramesh demonstrates a non-euclidean ray tracer:

This other video by the MIT Game Lab demonstrates OpenRelativity, a Unity toolkit allowing simulation of navigation at relativistic speeds, used for the prototype game A Slower Speed of Light:

Update: Sylvain mentioned in comments that Carl Sagan explains those effects in the following video:

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).


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.

TED talk about femto photography

I already mentioned the camera built by a team in the MIT Media Lab, allowing with its trillions of frame per second, to capture the propagation of light or to see around corners.

TED published a video of the talk given by Ramesh Raskar, where he presents this work and the new possibilities it opens.

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.