Accurate Volume Rendering Based on Adaptive Numerical Integration

We present an adaptive integration strategy to evaluate the volume rendering integral for regular volumes. We discuss different strategies to control the step size for both the inner and the outer integrals in the volume rendering equation. We report a set of computational experiments that compare both accuracy and efficiency of our proposal against Riemann summation with uniform step size. The comparisons are made for both CPU and GPU implementations and show that our method delivers both accuracy control and competitive performance.