The Tracing Methods

 
       

GRAPE(trace, "tracing")(start_time,end_time)

GRAPE(trace, "tracing-disp")()

TRACE *trace
double start_time,end_time

The trace is rendered only from start_time to end_time. The rendering style is the same as for the method "display". In the interactive case start_time and end_time are identical to the start_time and end_time of the moving method.

 
Figure 7.4:  tracing

       

GRAPE(timestep, "tracing")(start_time,end_time)

GRAPE(timestep, "tracing-disp")()

TIMESTEP *timestep
double start_time,end_time

This method first checks whether the objects in the sequence of timesteps are of a subclass of Triang1d or not. If not the method is ignored. Otherwise a segment of the trace of a moving curve is rendered from start_time to end_time. The rendering style is that of a triangulated surface. In the interactive case start_time and end_time are identical to the start_time and end_time of the moving methods.