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

Implementation4.6. Implementation of Data Consumers4.6.2 SoMapperNodeFigure 4.20: DataAccessMap: Accessing virtual array using the attributes offset, inc, length, label and datatype (not shown)SoMapperNode is one of the core parts, containing the visualization algorithms.Both of them can use several input streams and generate from one to many outputstreams This is also known as fan–in and fan–out.The process flow between mapper and renderer gets more obvious in figure 3.15 onpage 64.The basic data access introduced in the UML class hierarchy (figure 4.5 on page 71)only shows an indirect way to access data from a DataComsumer. The UML sequencediagram in the next section 4.2.1 will provide more detailed information on that.the most important representatives are:• Texture Generation• Streamline and Particle Tracer• iso–surface extractionSoMapperNode - File FormatThis sample file generates a parameterization similar to the one shown in figure 5.9and figure 5.10 on page 108. The field lookup_kind defines one of the three kinds ofmappings:0 .... constant mappingAll values in the interval are mapped to one constant output value. In our examplethe input interval 10 is [7..9] and the constant output value is 4.1 .... linear mappingAll values in the interval are mapped linear to the output value. In our examplethe input interval is [3..7). Since the output interval [6..4) decreases while theinput interval increases an inverse linear mapping is achieve.10 Definition of intervals: brackets [ ] define a closed interval while ( ) define an opened interval.94