The Ray Tracing (
) study and study step are used to compute the trajectories of rays. The Ray Tracing study step is a special case of the Time Dependent study step. The time steps taken by the solver can either be specified directly or by specifying a set of path lengths and a characteristic group velocity. Built-in stop conditions can be used to stop the solver when no active rays remain, or when the intensity of active rays is negligibly small. Except for the section below, see
Time Dependent for all settings. This study requires the Ray Optics Module or the Acoustics Module.
From the Tolerance list, choose
Physics controlled (the default) to use the tolerance suggested by the physics. Choose
User controlled to override the suggested relative tolerance with a value that you enter in the
Relative tolerance check field. The tolerance settings control the internal time steps taken by the solver, so selecting large time steps for the output times does not affect the accuracy in the time stepping.
Select a Stop condition:
None (the default),
No active rays remaining,
Active rays have intensity below threshold, or
Active rays exceed maximum number of reflections. If
No active rays remaining is selected, the solver terminates immediately when all rays are stuck, frozen, or have disappeared.
If Active rays have intensity below threshold is selected, enter a
Threshold ray intensity (the default is
1[W/m^2]). The solver terminates immediately when all rays are either stuck, frozen, have disappeared, or have intensity less than the threshold. This setting can only be used if the ray intensity is computed for the Geometrical Optics or Ray Acoustics physics interface (select any option other than
None from the
Intensity Computation list in the physics interface
Intensity Computation section.
If Active rays exceed maximum number of reflections is selected, enter a
Number of reflections (the default is
5). The solver terminates immediately when all rays are either stuck, frozen, have disappeared, or have been reflected or refracted at least the specified number of times. This setting can only be used if the
Count reflections check box has been selected in the
Additional Variables section for the Geometrical Optics or Ray Acoustics interface.