Occlusion is one of the major challenges in 3D grids. In this thesis we present different approaches to tackle the problem of occlusion in 3D grids. In order to visualize occluded objects some techniques remove a portion of the remaining grid (the occluding part) while others keep all the data exposing the occluded objects by splitting and shifting the remaining grid. In this work we propose the use of the Cutaway Views technique to improve the inspection and analysis of grid cells in corner-point grids, and we also present a system for creating interactive Exploded View Diagrams in generalized 3D grids.
The Cutaway View technique was used to improve the inspection and analysis of grid cells in corner-point grids. This approach places objects (or parts) of interest in focus by removing occluders. One important point is the notion of keeping the focused object in context within the whole scene. This is particularly challenging in cases where cells are tracked not only by spatial (geometrical and topological) information but also by their containing values, shifting the paradigm of traditional illustrative techniques. Here, we propose a first investigation on how to adapt the Cutaway approach to track grid cells either by spatial location or by value.
In regards to the Exploded View technique, the primary difference between our approach and existing research is that our technique neither requires geometrical information of the whole model nor any information regarding the relationship among model parts; instead our implementation depends on which grid cells are marked as primary objects, and which view angle to use. To achieve this, we introduce the Explosion Tree, a data structure closely related to a BSP tree, which is based on the relationship between grid cells and the gaze. We discuss the application of this technique to both synthetic and real data. In this thesis, regular grids are synthetically generated while non-regular grids are composed of real data. More specifically, the type of non-regular grid presented in this work is known as a Corner-Point grid which has been widely used for flow simulation and geological modeling.