Making the subtle obvious, follow-up

A couple of months ago I was posting here about this SIGGRAPH publication on amplification of details in a video. Yesterday the New York Times put online a story as well as a video on the topic, with explanations from the authors and some new examples.

Making the subtle obvious

Take a video, decompose it into several frequency components, filter and amplify each one, recompose them back to an output video, profit. Nuit-Blanche mentioned this paper presented earlier this year at SIGGRAPH. I never thought you could actually detect the blood flow from a simple video…

Update: more to see in this follow-up post.

Short reading list on diffuse lighting

This is going to be a short one: I haven’t done any extensive search, but I still want to make a back of the envelope note with a couple of links.

Paths of Hate

Paths of Hate is one of the many animations that were shown at the Computer Animation Festival at SIGGRAPH 2011, and among the ones that drew most attention (it was awarded the Jury Award). Directed by Damian Nenow, the film explores in a comic style how deep hatred can go. Unfortunately I haven’t found the long version on Internet, only the following trailer. If you have the opportunity to see the full version, do not miss it.

Readings on physically based rendering

Physically based rendering (PBR) seems to be the hot thing recently in game as well as film industries. Last year at SIGGRAPH Naty Hoffman led a course on physically based shading. The first talk in particular gives some excellent insights on the physics behind lighting.

This year, at SIGGRAPH again, the physically based lighting used in Call of Duty: Black Ops was one of the topics of the course Advances in Real-Time Rendering in 3D Graphics and Games. Keith Judge wrote an article to sum up the ideas presented in this talk in shading language. Sébastien Largarde also has some insights on the shift to physically based shading from a production point of view.

On a narrower topic Rory Driscoll briefly explained the problem of energy conservation, a first but important step toward PBR, in a convincing and straight to the point manner. In articles mentioning normalization factors the origin is not always clear, especially when authors take shortcuts to avoid digressing from their topic. Fortunately Fabian Giesen wrote a demonstration of the normalization factor for the Phong and Blinn-Phong models and Chris­t­ian Schüler gathered various of the normalization terms we can see in publications, with proper references.

There are many other sources to read, but I will stop there for now. Just follow the links and you have plenty of reading already. ;)

Addendum: Sébastien pointed out this article on energy conservation for wrapped diffuse lighting and this one on physically plausible microfacet BRDF, which includes a WebGL demo to play with.

Update: Tri-Ace has made a couple of presentations on the matter over the last years, which you can find on their research page.

Update: this article, Basic Theory of Physically-Based Rendering, presents the ideas of PBR in a very easy to read manner and works well as an introduction.