Efficient Rendering of Ocular Wavefront Aberrations using Tiled Point‐Spread Function Splatting

Abstract

Visual aberrations are the imperfections in human vision, which play an important role in our everyday lives. Existing algorithms to simulate such conditions are either not suited for low-latency workloads or limit the kinds of supported aberrations. In this paper, we present a new simulation method that supports arbitrary visual aberrations and runs at interactive, near real-time performance on commodity hardware. Furthermore, our method only requires a single set of on-axis phase aberration coefficients as input and handles the dynamic change of pupil size and focus distance at runtime. We first describe a custom parametric eye model and parameter estimation method to find the physical properties of the simulated eye. Next, we talk about our parameter sampling strategy which we use with the estimated eye model to establish a coarse point-spread function (PSF) grid. We also propose a GPU-based interpolation scheme for the kernel grid which we use at runtime to obtain the final vision simulation by extending an existing tile-based convolution approach. We showcase the capabilities of our eye estimation and rendering processes using several different eye conditions and provide the corresponding performance metrics to demonstrate the applicability of our method for interactive environments.

Rendering algorithms for aberrated human vision simulation

“…The PSF grid was too coarse to properly simulate off-axis vision and the slicing caused banding Csoba and Kunkli [43] This work used spectacle lens prescriptions to simulate low-order aberrations in real-time environments by utilizing separable complex kernels to approximate the PSFs HOA were not supported and chromatic aberration and peripheral vision were ignored Csoba and Kunkli [44] The authors estimated the physical eye structure from aberrations to compute a coarse PSF grid for varying parameters and simulated vision with an approximately real-time performance profile using tiled convolution and a novel GPU-based per-pixel PSF interpolation approach…”

“…More recently, Csoba and Kunkli [44] proposed the use of the extended Nijboer-Zernike (ENZ) diffraction theory [48] as an alternative means of computing human PSFs for vision simulation purposes. The ENZ approach is based on the more accurate Debye-Wolf diffraction integral [49] and defines the PSF as a linear combination of a set of independent functions.…”

“…To overcome these limitations, Csoba and Kunkli [44] utilized tiled splatting [51] with a GPU-based PSF interpolation technique to simulate visual aberrations at approximately real-time frame rates. Instead of relying on the convolution theorem, their approach performs a convolution directly in the spatial domain.…”

“…Alternatively, if the eye structure is available, aberration coefficients can also be obtained using ray tracing and least-squares coefficient fitting, the applicability of which was demonstrated by Csoba and Kunkli [44]. Their approach estimates the physical properties of the simulated eye by fitting the parameters of a customized eye model to the input monochromatic aberration coefficients.…”

“…Complex phasors can also be used for vision simulation, as demonstrated by Csoba and Kunkli [43]. Their approach computes the PSF of the simulated eye using the Fraunhofer diffraction formula and fits an ellipse to the resulting PSF.…”