Use the Ray Detector feature to compute information about rays that are located in a set of selected domains or on a set of selected boundaries. The detector may detect all rays or only the rays released by a specified release feature. Computed variables are the number of rays transmitted, the transmission probability, and a logical expression which can be used to filter the rendered rays during results processing.

The Ray Detector feature is also capable of computing the total transmitted ray power. If Compute intensity and power or Compute intensity and power in graded media is selected from the Intensity computation list in the physics interface Intensity Computation section, then a global variable for the total power transmitted to the detector is available.

Select an option from the Release feature list—All (the default), or any of the features which are capable of releasing rays. When All is selected, the variables computed are summed over all release features in the model.