Ray Tracing is used in EASE for a variety of purposes. It’s used to study the propagation of sound rays into the room (reflection studies), to calculate local RT times and for advanced acoustical analysis. Rays are released into the Model and each ray’s path traced until it reaches predetermined limits.

In its simplest form, Ray Tracing allows the study of reflection patterns within the model by emitting rays whose reflection paths can be viewed and investigated. The key words in the previous sentence are “reflection patterns’. The basic Ray Tracing routine does not allow the investigation of reflections that hit a specific spot within the model. Comparatively few rays are needed to produce the quantity needed for reflection path studies; usually only a few hundred rays and low reflection orders are all that is required. These studies, however, do not provide the detailed information needed for in depth acoustical analysis and for EARS auralizations.

Movies, a Ray Tracing option allows viewing the sound rays propagation into the room model in a movie format that is both eye-catching and informative.

Both EASE and EASE JR offer Ray Tracing and the Movie Display. In EASE JR, however, Ray Tracing studies are limited to 1000 Rays and up to 3rd Order reflections. Ease Ray Tracing studies are not limited in the number of Rays that can be used and in the number of reflections.

EASE also offers two variations of Ray Tracing, Local Decay Times and Local Ray Tracing. Local Decay Times provides a quick means of checking the RT Times at various locations by distributing Rays throughout the room and calculating the “local” RT times from the decay times. Local Ray Tracing provides an easy way to take a more in-depth look at selected locations by producing a Reflectogram showing the arrival times and energy levels of all the direct and reflected Rays that reach the selected point.

Two additional Ray Tracing options, Mirror Image Impacts and Find Impacts, provide for the detailed investigation of reflections that hit (impact) a specific location within the model. Both methods provide the detailed information needed for in-depth acoustical analysis and for EARS auralization.

Find Impacts is a Ray Tracing option that registers rays that pass within a meter of the chosen point (impact upon a 1 meter counting balloon), stores the results and then uses a Mirror Image routine to identify the impacts that hit the center of the counting balloon. It relies upon the laws of probability to identify an adequate number of impacts to ensure an acceptable degree of accuracy. Find Impacts requires a larger number of rays and higher reflection orders than simple Ray Tracing.

Mirror Image Impacts involves a systematic search for all possible reflections that hit the chosen point and then stores detailed information on each of these reflections. It is a more accurate method than Find Impacts since it doesn’t rely upon the laws of probability, but the amount of computation time required is much longer. Both methods, Find Impacts and Mirror Image Impacts, yield results that are suitable for detailed acoustical investigations and EARS auralizations.