Gamescom 2015 might be ending, but other conventions are due to start soon. SIGGRAPH 2015 will open tomorrow in Los Angeles, for example, and although it's an event mainly geared towards developers there are some interesting things for gamers, too.

　　The Advances in Real-Time Rendering in Games course will host many developers working on high-profile games, such as Quantum Break, Horizon: Zero Dawn and Dreams.

　　Andrew Schneider, Principal FX Artist at Guerrilla Games, will present a session on The Real-time Volumetric Cloudscapes of Horizon: Zero Dawn. Here's an abstract with more details:

　　Real-time volumetric clouds in games usually pay for fast performance with a reduction in quality. The most successful approaches are limited to low altitude fluffy and translucent stratus-type clouds. For Horizon: Zero Dawn, Guerrilla need a solution that can fill a sky with evolving and realistic results that closely match highly detailed reference images which represent high altitude cirrus clouds and all of the major low level cloud types, including thick billowy cumulus clouds. These clouds need to light correctly according to the time of day and other cloud-specific lighting effects. Additionally, we are targeting GPU performance of 2ms. Our solution is a volumetric cloud shader which handles the aspects of modeling, animation and lighting logically without sacrificing quality or draw time. Special emphasis will be placed on our solutions for direct-ability of cloud shapes and formations as well as on our lighting model and optimizations.

　　Ari Silvennoinen and Ville Timonen, Graphics Programmer at Remedy, will demonstrate Multi-Scale Global Illumination in Quantum Break.

　　This talk will cover Remedy’s approach to multiscale global illumination in Quantum Break. Firstly, we present an efficient voxel tree structure and demonstrate its applications to world-space global illumination and to automatic specular probe generation using local visibility analysis. Secondly, to complement the large-scale illumination, we present our screen-space lighting solution which handles small scale ambient occlusion, reflections, and indirect lighting.

　　Alex Evans, Co-Founder and Technical Director at Media Molecule, will focus on the history of Dreams' renderer in his Learning from Failure: a Survey of Promising, Unconventional and

　　Mostly Abandoned Renderers for ‘Dreams PS4’, a Geometrically Dense, Painterly UGC Game’ session.

　　Over the last 4 years, MediaMolecule has been hard at work to evolve its brand of ‘creative gaming’. Dreams has a unique rendering engine that runs almost entirely on the PS4’s compute unit (no triangles!); it builds on scenes described through Operationally Transformed CSG trees, which are evaluated on-the-fly to high resolution signed distance fields, from which we generate dense multi-resolution point clouds. In this talk we will cover our process of exploring new techniques, and the interesting failures that resulted. The hope is that they provide inspiration to the audience to pursue unusual techniques for real-time image formation. We will chart a series of different algorithms we wrote to try to render ‘Dreams’, even as its look and art direction evolved. The talk will also cover the renderer we finally settled on, motivated as much by aesthetic choices as technical ones, and discuss some of the current choices we are still exploring for lighting, anti-aliasing and optimization.

　　None of these sessions will be livestreamed, but you can expect the powerpoint slides to be eventually uploaded to the site; we'll report a news once that happens, as there may well be some nice insight to share about the technology behind these games.