Virtual Reality

Virtual reality has never been stronger on the PC platform, and NVIDIA wanted to share the Turing love in this field as well. Accordingly, they put an emphasis on identifying the current major issues to tackle, and provided more information on how the Turing microarchitecture helps take things forward in that regard. We already saw how NVIDIA RTX ray tracing works in providing real-time, accurate lighting and scene illumination. With immersiveness being the key factor with VR, this already implemented technology also comes into play here—even more so if everything we have heard from VR developers thus far is anything to go by. The shading technologies discussed on the previous page add more icing to this VR cake.


Another improvement in visual fidelity with Turing comes in the form of Multi-View Rendering (MVR), which has been brought up in the past by NVIDIA and others alike. MVR allows developers to tackle scene rendering from multiple viewpoints simultaneously, as the name suggests, which automatically sees a role in mixed reality headsets, including VR. Another application of MVR is to have multiple character poses in a single pass, thus allowing the audience to see over and around the first plane image of the subject in question. Turing supports up to four views per pass, and up to 32 views at the API level. With such multiple views possible, and combined with ray tracing, one of the example use cases suggested by NVIDIA is having accurate reflections depicted in VR, given how there are multiple incident occurrences depending on the subjects and the source in question. MVR is an extension of Simultaneous Multi-Projection (SMP) that was introduced with Pascal, wherein SMP was limited to two views, thus keeping multi-object interactions to a minimum. MVR retains the support for up to 16 projections per view, while increasing the number of views as mentioned above.

The first image above shows how MVR is all the more effective in VR by providing first a look at image rendering on a 200° FOV screen using two canted panels angled outwards. MVR will theoretically also allow a more accurate calibration and alignment of the VR user's face to the headset since the developer no longer has to assume the user's eyes are just offset in one axis. The second figure illustrates how MVR works with a single-pass shadow map render. In particular, a set of two characters (top right) are rendered from the same mesh despite the mesh itself being rendered once, and the accompanying set of four shadow depth buffers (top left) possible due to the multiple views is handled with Turing.


VR immersiveness is more than just video, however, as audio plays just as important a role. NVIDIA VRWorks Audio was introduced with Pascal and helps provide binaural audio elements using the NVIDIA OptiX software ray tracing engine for better simulation of indirect and background sound. This helps tackle sound bouncing off of surfaces, which arrives at a different time relative to direct, uninterrupted audio. Add in support for such reverberations off of different types of surfaces, and things are already looking good. With Turing, the available RT cores help enable more accelerated sound ray tracing—up to six times faster than Pascal via VRWorks Audio, as rated by NVIDIA.


Arguably the most impactful update to VR comes in the form of hardware support in Turing to the new VirtualLink standard. We will go over this in more detail in subsequent pages pertaining to the display technologies introduced here, but as a summary—VirtualLink is a new open standard that allows an alternate use of the USB-C to deliver power and data, and display simultaneously via a single USB-C connector. This means that one no longer has to be bound by multiple HDMI and USB cables, and all this is possible due to VirtualLink, which supports four lanes of High Bit Rate 3 (HBR3) DisplayPort along with SuperSpeed USB 3 link on all four lanes—something not possible by the USB-C standard alone. VirtualLink has received support already from NVIDIA, AMD, Oculus, Valve, Microsoft, and others, so this should also allow for new headsets coming up with a single connector in the near future. Think of the freedom in motion possible with a single, thin cable as well as the free ports now available on your PC for other purposes, and tell me you would not want that.