Visualization and Interpretation of 3D Geological and Geophysical Data in Heterogeneous Virtual Reality Displays: Examples from the Chicxulub Impact Crater
Many geological data sets are truly three-dimensional (3D) but are ordinarily viewed and interpreted in two-dimensional (2D) space. We are developing an immersive visualization system that allows an interpreter to navigate, manipulate and interpret 3D data directly in 3D virtual reality space. The system also allows the interpreter to collaborate with remote users in real time, even though they may be in different locations and using different display types. We describe our system for collaboration between a user of a physically immersive display and a user of a mirror-based "fish tank" display.
The system's utility is illustrated using combined geophysical, geological and topographic data sets over the Chicxulub Impact Crater on the Yucatan Peninsula. We present images with interpretive marks, shown from the perspective of a user immersed in a stereoscopic head-mounted display system. In this display, position and orientation of the head are tracked to control the point of view and the interpreter navigates the environment by walking around naturally. A hand-held controller is used for manipulation of features such as height-based coloring, slope-based shading, scaling, image overlays, and mesh resolution. The stereoscopic visual display and motion parallax provide a sense of depth not available with conventional computer displays, and the natural navigation mechanism allows features to be easily viewed from various directions, distances, and perspectives until the best view to interpret the data is achieved.
Interpretation of the Chicxulub Impact Crater data is at an early stage. However, the advantages of interpretation in our virtual reality system have already led to recognition of new features in the topographic data and of new correlations between the topographic and gravity data sets.
A video is included on the CD to illustrate the manipulations and interpretations and to demonstrate the advantages of moving in the 3D virtual reality space when interpreting the data set.
Several individuals and organizations have contributed in various ways to this research. Adam M. Guichard, Arun P. Indugula, and Alp V. Asutay worked on the software implementation during graduate studies in the Center for Advanced Computer Studies, and student Chandana Tulasi made preliminary contributions to this effort. Manuel Hurtado Cardador has collaborated in our Chicxulub research since the beginning. He has been in the field and has acquired data and support from both Instituto Mexicano del Petroleo and Petroleos Mexicanos. Kevin Pope originally involved author Kinsland in Chicxulub research and continues to contribute interpretations and discussions. Michael Kobrick with the North American Space Agency's Jet Propulsion Laboratory arranged for us to obtain the SRTM data. Louis Paul Bedard produced the gravity files as part of his master's thesis. Gary Sanchez manipulated and organized the SRTM data. Zack Long and Mauricio Cruz Cisneros were part of a 2002 field excursion. C & C Technologies loaned the CNAV® autonomous differentially corrected GPS instrument used to collect the profile. A grant from the Society of Exploration Geophysicists supported the 2002 field excursion.