Internet-connected devices will theoretically be able to offload graphical computation onto the cloud. But what would that actually look like? Nvidia's CloudLight demo shows off how the cloud could be used to calculate indirect lighting in games.
CloudLight essentially computes lighting data on a cloud-based server, and then transfer it back to the end user. By focusing on indirect light, Nvidia is trying to overcome the biggest potential pitfall for cloud computing in games: latency. Because direct illumination is still rendered on a local client, cloud-based indirect lighting is an additive feature.
Nvidia argues that cloud rendering makes sense for this purpose because it is effective even when an internet connection is unreliable. "In the worst case, the last known illumination is reused until connectivity is restored, which is no worse than the pre-baked illumination found in many game engines today," Nvidia's report details. As seen in the video below, even with significant latency, the effect is rather subtle, making a scene feel a bit more ephemeral.
There are three approaches Nvidia is taking with cloud-based lighting, but voxels are especially exciting because it is ideally suited for mobile devices. With this method, light data is encoded into 3D points that get transferred via H.264 video compression. It require "almost no computation burden on client devices." Although not practical for large scenes, the low bandwidth and computational requirements for voxel-based light rendering could make it ideal for tablets and phones. And, "in the near future, thermal limits on mobile devices are unlikely to be overcome. To continually improve visual quality at the rate consumers have come to expect, the only solution may be to move some computation to the Cloud," Nvidia says.
There are still practical concerns regarding bandwidth, but it's nonetheless a fascinating proof-of-concept on the potential of deferred rendering. One can only assume that Microsoft will want to get in touch.