Experiments with DirectX Raytracing in Remedy’s Northlight Engine

At the Game Developers Conference 2018 in San Francisco today, Remedy Entertainment discussed the experiments and research they have done in collaboration with NVIDIA on the Microsoft DirectX Raytracing (DXR) API that enables straightforward access to real-time ray tracing running on development graphics hardware.

Remedy has been granted early access to conduct research on this technology and has been researching how to utilize the NVIDIA RTX ray tracing technology and the DX R API in its Northlight engine. Remedy is one of the few handpicked game development studios in the world chosen to work on DirectX Ray Tracing.

Remedy’s lead graphics programmer Tatu Aalto presented the early results of the experiments at GDC’s Advanced Graphics Techniques Tutorial on March 19th in his presentation, titled Experiments with DirectX Raytracing in Remedy’s Northlight Engine.

The slides from the presentation can be viewed here.

Ray tracing itself is not a new technique: GPU ray tracing has been possible before through offline rendering, custom implementation or external APIs. Until now, ray tracing in real-time, interactive gaming has been too computationally demanding to be practical, because gaming requires high frame rates and low latency. The new NVIDIA RTX removes those limitations.

Via the DXR API it is possible to bring real-time ray tracing into the game engine and create a seamless hybrid between the rasterized and the ray traced image. Ray tracing can be used to add quality and accuracy to rendering techniques that are difficult to achieve with traditional rasterization techniques.

Some of the improvements include accurate soft shadows, ambient occlusion, reflections and global illumination. For gamers, this means even better looking games.

The video above was captured from the Northlight engine with all the raytracing effects enabled and with increased sample counts.

“Integrating NVIDIA RTX technology into our Northlight engine was a relatively straightforward exercise. Developing exclusively on NVIDIA GPUs, we were surprised just how quickly we were able to prototype new lighting, reflection, and ambient occlusion techniques, with significantly better visual fidelity than traditional rasterization techniques. We are really excited about what we can achieve in the future with NVIDIA® RTX. Gamers are in for something special”, said Mikko Orrenmaa, the Technology Team Manager of Remedy Entertainment.

“Remedy has accomplished something very exciting in a short amount of time using NVIDIA RTX on Microsoft’s DXR,” said Tony Tamasi, senior vice president of content and technology at NVIDIA. “The combination of today’s powerful GPUs, industry standard API support and game engine integration finally puts real-time ray tracing within reach for the graphics industry and game developers.”

This technology remains at research level, and as such it is far from being implemented into a video game, but it is an intriguing glimpse of things to come.