Improving rendering performance

Any techniques that improve rendering performance in the broad field of computer graphics apply here; however, one must avoid cases in which side effects that were imperceptible on a computer display become noticeable in VR. It was already mentioned in Section 7.2 that texture and normal mapping methods are less effective in VR for this reason; many more discrepancies are likely to be revealed in coming years. Regarding improvements that are unique to VR, it was mentioned in Sections 7.2 and 7.3 that the stencil buffer and multiresolution shading can be used to improve rendering performance by exploiting the shape and distortion due to the lens in a VR headset. A further improvement is to perform rasterization for the left and right eyes in parallel in the GPU, using one processor for each. The two processes are completely independent. This represents an important first step, among many that are likely to come, in design of GPUs that are targeted specifically for VR.