For trajectory plots, such as Particle Trajectories and Ray Trajectories, it is often useful to plot the particle or ray positions at specific times other than the time steps stored in the solution. This is often the case when particles or rays are reflected at boundaries; the exact reflection times are usually not known in advance, so they cannot be specified in the settings for a transient study step and must be computed instead. Similarly, intersection point datasets are not guaranteed to find all intersections close to wall bounces.

The Extra Time Steps section is always available in Intersection Point 2D and Intersection Point 3D datasets. It also appears in when a plot supports the rendering of particle or ray positions at time steps other than those stored in the solution. The plot must refer to a valid Particle or Ray dataset.

Select an option from the Maximum number of extra time steps rendered list: None, Specified number of times (the default), or Proportional to the number of solution times. For None the trajectories are only plotted at the stored solution times.

For Specified number of times enter a nonnegative integer for the Maximum number of extra time steps. The default is 100. This value is the total number of extra time steps, typically corresponding to reflection or velocity reinitialization times, that can be plotted along each trajectory in addition to the stored solution times.

For Proportional to the number of solution times enter a nonnegative integer for the Proportionality factor. The default is 1. The maximum number of extra times shown in the trajectory plot is the product of the proportionality factor and the number of stored solution times shown in the plot.