Interactive Transfer Function Specification for Direct Volume Rendering of Disparate Volumes

Transfer functions play a critical role in feature detection through direct volume rendering in volumetric scalar fields. Because of the inherent difficulties of exploratory visualization, assisting the user in transfer function specification is still an important area of research. In particular, the disparate nature of simulated and measured volumetric data necessitates more flexibility in the specification process than existing tools provide. In this paper, we introduce a framework that combines elements of existing techniques as well as introduces new features to handle the diversity of volumetric datasets. The contributions of our work include a range mapping technique for assisting in transfer function specification for high dynamic range data, an algorithm for combining multiple transfer functions into ensembles that allow multiple specification techniques to be used collectively, and an intuitive method for specifying transfer functions for multiple classes of time-varying data. Bernardon et al.: Interactive Transfer Function Specification for Direct Volume Rendering of Disparate Volumes Interactive Transfer Function Specification for Direct Volume Rendering of Disparate Volumes Fábio F. Bernardon, Linh K. Ha, Steven P. Callahan, João L. D. Comba, and Cláudio T. Silva, Member, IEEE Abstract—Transfer functions play a critical role in feature detection through direct volume rendering in volumetric scalar fields. Because of the inherent difficulties of exploratory visualization, assisting the user in transfer function specification is still an important area of research. In particular, the disparate nature of simulated and measured volumetric data necessitates more flexibility in the specification process than existing tools provide. In this paper, we introduce a framework that combines elements of existing techniques as well as introduces new features to handle the diversity of volumetric datasets. The contributions of our work include a range mapping technique for assisting in transfer function specification for high dynamic range data, an algorithm for combining multiple transfer functions into ensembles that allow multiple specification techniques to be used collectively, and an intuitive method for specifying transfer functions for multiple classes of time-varying data.Transfer functions play a critical role in feature detection through direct volume rendering in volumetric scalar fields. Because of the inherent difficulties of exploratory visualization, assisting the user in transfer function specification is still an important area of research. In particular, the disparate nature of simulated and measured volumetric data necessitates more flexibility in the specification process than existing tools provide. In this paper, we introduce a framework that combines elements of existing techniques as well as introduces new features to handle the diversity of volumetric datasets. The contributions of our work include a range mapping technique for assisting in transfer function specification for high dynamic range data, an algorithm for combining multiple transfer functions into ensembles that allow multiple specification techniques to be used collectively, and an intuitive method for specifying transfer functions for multiple classes of time-varying data.