Maximizing depth buffer range and precision

Half of the available range is packed into tiny distance from the near plane to twice the near plane distance.

This quote from this article of the Outerra blog is more or less its punch line. The author explains the precision issues with typical depth buffer use, and explores ways to get better results. Since Outerra is a planet engine, no wonder depth precision must be critical.

I discovered Outerra and its blog fairly recently, through a couple of mentions in the Flipcode’s Daily Flip, and was impressed by its rendering. The amount of work that went into it must be insane. See these captures demonstrating the space to ground transition or the grass rendering for instance:

Crysis 3 tech demo

Crytek has published a video showing the rendering technology used in the CryEngine, more specifically in Crysis 3. While I don’t really dig the artistic choices (I find the overall image to be messy due to the high contrast and not that appealing, aesthetically speaking), the technical side is impressive. I especially like the use displacement mapping and tessellation for the vegetation (by the way, see how great that leaf looks; they got the material completely right). The reflexions visible at 1’52 make me think they also implemented the cone tracing technique, just like Unreal did. On the downside, all the parts with falling water felt unrealistic to me.

Last but not least, Toad Technology! :)

Is tiled forward rendering the new hot thing?

I see more and more people talking about tiled forward rendering, and it seems to be the new hot thing everyone wants to try. AMD recently released a tech demo using such a technique: Leo.

Aras Pranckevičius, rendering architect at Unity, discussed modern forward rendering in an article, 2012 Theory for Forward Rendering, and later dropped a bunch of Tiled Forward Shading Links (which I won’t duplicate here so just click). Wolfgang Engel argues tiled based approaches don’t pay back when many lights cast shadows, compared to deferred lighting. At last Brian Keris discusses Tiled Light Culling, for the diffuse and specular contributions.