Valve programmer says latency is the enemy of virtual reality

Latency is the enemy of virtual reality, according to a post on Valve's blog by Michael Abrash, a programmer at the developer.

After revisiting the old VGA days and explaining the cumbersome nature of getting colors to display properly, he breaks down virtual reality's abilities going forward.

"When it comes to VR and AR," he said, "latency is fundamental — if you don't have low enough latency, it's impossible to deliver good experiences, by which I mean virtual objects that your eyes and brain accept as real."

Latency matters because virtual objects "have to register as being in almost exactly the right position all the time." If there's any delay between what the brain expects and what the software and hardware can deliver, it will ruin the effect.

To compound the challenge, the VR hardware and software need not only render and display information with a latency of as little as seven milliseconds, but track your head's position in the real world and update the display so quickly that it's indistinguishable from real time.

It's a complicated solution to solve, but he's up for the challenge.

"If you ever thought that AR/VR was just a simple matter of showing an image on the inside of glasses or goggles," he said, "I hope that by this point in the blog it's become clear just how complex and subtle it is to present convincing virtual images — and we've only scratched the surface. Which is why, in the first post, I said we needed smart, experienced, creative hardware and software engineers who work well in teams and can manage themselves — maybe you? — and that hasn't changed."