Abstract:
Uncertainty in various forms is prevalent throughout Archaeology. With archaeological site data in particular, the dating regularly has significant uncertainty. In this paper we present an application that enables integrating and visualizing the temporal uncertainty for multiple 3D archaeological data sets with different dating. We introduce a temporal time window for dealing with the uncertainty and review various visual cues appropriate for revealing the uncertainty within the time window. The interactive animation of the time window allows a unique exploration of the temporal uncertainty.
The motivation of this paper is based on the fact that in an archaeological site, all the recorded data usually represents a minuscule fraction of the information regarding the visual appearance of a site over time. Therefore the missing data forms a major component of the uncertainty. From the available data, the dating regularly has significant uncertainty.
ResponderEliminarThis paper is about an application designed to integrate and visualize the temporal uncertainty for multiple 3D archaeological data sets with different dating. The authors introduce a temporal time window for dealing with uncertainty and review several visual cues that are adequate for revealing uncertainty within the time window.
The time window is based on the camera shutter concept, therefore it allows effects such as motion blur to be created for moving objects, or a moving camera. But also, it enables events on either side of a specific date to be viewed to take into account uncertainty in the actual viewing time. The width of the window represents the range of time and can be controlled by the user.
In the current context, a visual cue is any visual encoding used to distinguish levels of uncertainty. There are mainly two visual cues that are used in the scope of this work: transparency and rising/sinking animation. The determination of which cues are more appropriate to use depend on task and hardware considerations.
The application is called ArkVis and was written in C++ (Visual Studio) and uses OpenGL and nVidia’s Cg language for rendering the 3D scene and the visual cues. The model loading is based on a 3DS import library.
This system was applied to the archaeological data of Mahram Bilqis sanctuary (Yemen) regarding the oval wall of the temple. There are distinct reconstructions of the wall: one is based on a theoretical reconstruction of the site at an early date, the other is based on a recent survey where accurate measurements where took .In this case wireframe and transparency uncertainty cue, associated to interactive animation (using a time slider and time window), are used to allow the user to understand the assumptions in the earlier theoretical data set.
However, it is not clear what representations of uncertainty are most appropriate for which task. Each visual cue will have its advantages and drawback and they will depend on hardware considerations.
It is clear that this method and application is an easy way to cognitively merge multiple data that represent different time periods. This kind of visualization will serve both the general public and the domain experts. For the general public it is able to provide comprehensible visual explanations, while for the domain experts it might be useful in cognitive tasks such has hypothesis building.