Seamless Integration of Multimodal Shader Compositing into a Flexible Ray Casting Pipeline

Abstract

In the last three years a number of multi-volume GPU ray casting systems have been presented. Some of them are very powerful and provide a wide variety of features. However, these approaches are either only capable of displaying multiple modalities together without logically combining them or they lack the necessary flexibility for rapid visual development. These features are fundamental for visualizing the coherent information of multimodal data. In this paper we therefore present an integrated way of visually specifying a volume rendering pipeline including a flexible multimodal compositing of sampling, transfer functions, logical operators and shading. As a result the data flow can be visually constructed and retraced from preprocessing through to the shader operations. Hence intuitive visual prototyping of multimodal transfer function compositing is possible at runtime.