3D scalar data visualization has been well accepted as a powerful means to allow scientists to explore large data sets, and to present their results to a wider audience. However, most of these visualization techniques have been designed on an assumption that the 3D scalar data to be represented are free from uncertainty. This is rarely the case in the real world, as uncertainty is pervasive in 3D scalar data and there is a growing need to depict the uncertainty in 3D scalar data visualization. Overlooking such depictions in 3D scalar data visualization could result in unfaithful...