Authors: Steffen Frey, Filip Sadlo, Kwan-Liu Ma, Thomas Ertl
Abstract: We present a novel scheme for progressive rendering in interactive visualization. Static settings with respect to a certain \ image quality or frame rate are inherently incapable of delivering both high frame rates for rapid changes and high image quality for \ detailed investigation. Our novel technique flexibly adapts by steering the visualization process in three major degrees of freedom: \ when to terminate the refinement of a frame in the background and start a new one, when to display a frame currently computed, and \ how much resources to consume. We base these decisions on the correlation of the errors due to insufficient sampling and response \ delay, which we estimate separately using fast yet expressive heuristics. To automate the configuration of the steering behavior, we \ employ offline video quality analysis. We provide an efficient implementation of our scheme for the application of volume raycasting, \ featuring integrated GPU-accelerated image reconstruction and error estimation. Our implementation performs an integral handling \ of the changes due to camera transforms, transfer function adaptations, as well as the progression of the data to in time. Finally, the \ overall technique is evaluated with an expert study.