The popularity of Virtual Reality has been on rising since quite some time now. But, one important thing that all VR users have known that the VR content could be very hard on the graphics card. If anyone wants to enjoy good VR content, then he or she needs to have a good graphics card. This is one of the major limitation in the mass popularity of Virtual Reality as many users do not have a dedicated graphics card for the VR content. This need for the high end graphics card forces developers to uses the rendering technology that can minimize the load on the graphic card but keep the overall performance same.
To tackle this issue, Oculus has come up with the new rendering technology known as Stereo Shading Reprojection. In the usual VR applications, an image is rendered twice, one for the right eye and one for the left one. But, the Stereo Shading Reprojection technique allows the pixels to be rendered just once. Then, the rendered pixels are projected to the other eye which reduces the time and resource requirement that was wasted in rendering the image twice.
The images need to be rendered twice as due to the distance between human eyes, each eye sees things in a slightly different perspective. One eye can see one thing which other cannot. While using Stereo Shading Reprojection technique, some pixels are more visible that should not be. But, to compensate this, software needs to identify which pixels are valid and which are not so that invalid pixels can be masked out to avoid ‘ghosting’ effect.
Oculus has said that they have tested this new technology in Unity using simple Shaders and buffers. This exaggerated the pixel cost by using dynamic lighting which resulted in drastic improvement in performance when reprojection was used. According to Oculus, 26% performance improvement was observed while testing the technology in Unity. The developers tested the technology using GTX 1080 and AMD R920 and observed similar improvements.
The sample code for download will be available soon from the Oculus site so that other developers can also use this technology.