Accelerating Transfer Function Update for Distance Map based Volume Rendering

TL;DR

This paper introduces a method to significantly speed up the update of distance maps in volume rendering, enabling high frame rates during frequent transfer function changes by using partitioned distance maps.

Contribution

The paper presents a novel partitioned distance map technique that accelerates transfer function updates in volume rendering by up to 30 times, maintaining high performance.

Findings

Up to 30x faster distance map updates.

Enables high frame rates during frequent transfer function changes.

Maintains real-time rendering performance in volume visualization.

Abstract

Direct volume rendering using ray-casting is widely used in practice. By using GPUs and applying acceleration techniques as empty space skipping, high frame rates are possible on modern hardware. This enables performance-critical use-cases such as virtual reality volume rendering. The currently fastest known technique uses volumetric distance maps to skip empty sections of the volume during ray-casting but requires the distance map to be updated per transfer function change. In this paper, we demonstrate a technique for subdividing the volume intensity range into partitions and deriving what we call partitioned distance maps. These can be used to accelerate the distance map computation for a newly changed transfer function by a factor up to 30. This allows the currently fastest known empty space skipping approach to be used while maintaining high frame rates even when the transfer function is changed frequently.