CashFlow, A Visualization Framework for 3D Flow - Studierstube ...

Software Design3.8. Grid Nodealgorithm is implemented it can access all grids via this abstraction layer. Specializedalgorithms optimized for speed defined on one specific grid can also be implemented.This concept is similar to the approach introduced by Patrick Moran [Mor01], whocreated the FIELD MODEL library [Mor03] at NAS[NAS] which is a C++ templatelibrary. It was also published at IEEE Vis2001 in Tutorial 1 [Tut01].Interface for accessing grids:• Geometric primitivesembedded in 3D– Vertex zero dimensional; Point in 3D– Edge one dimensional; Line.– Face two dimensional– Cell three dimensional• Connectivity informationcontains adjacency of Edge, Face and Cell. Each connectivity information canbe queried using the interface.• Grid iteratorsGrant access to each cell, each face and each edge for the algorithms.For most pairs of grids and visualizations special ways of fast rendering algorithmshave been published.3.8.2 Decoupling of Visualization Algorithm and Type of GridIn order to decouple the visualization method from the grid type we use the DesignPattern [Gam95] "Strategy" (page 373 in [Gam96] ) . Not all combinations of gridtypes and visualization techniques may be useful and possible, but never the less aseparation is very important.The design pattern is applied for the visualization techniques (see section 2.2page 19) and for the grid types.Figure 3.14: Design Pattern: Strategy [Gam95] [Gam96]60