Source Object
The source object creates a source with a size and shape based upon any other "parent" object. Any prior object in the NSC Editor may be used to define the shape of the Source Object, including User Defined and Boolean objects. Any changes in the properties of the parent object will dynamically affect the distribution of the rays on the Source Object. The parent object shape is used to determine the starting location and orientation of the rays. Rays are spatially distributed uniformly in area over the object. The angular distribution of the rays is given by
where θ is the angle measured from the local surface normal pointing outside the volume, and x is a user defined parameter between 0.0 and 400.0. If x = 0.0, the rays emanate in a hemisphere with equal probability in all directions. If x = 1.0, the distribution is Lambertian. If x >= 400.0, the rays are always normal to the surface.
For best results, the parent object should be a solid volume. If the parent object is a surface, the rays may radiate from either one or both sides of the surface, depending upon exactly how the parent object is defined.
There are two ways to prevent rays leaving the source from immediately striking the parent object. The first way is to set the Source Object to ignore the parent object from which it is defined. This will allow the ray to ignore the parent object until after the ray leaves the source (See "Defining an Ignore Objects list" ). The second way is to define a pre-propagation distance that is large compared to the chord tolerance but small compared to the distance the ray might legitimately travel before it interacts with the source itself (See " Sources tab " ). This latter method is useful if the interaction of the rays with the source body is desired and the source is hollow or concave so that rays leaving one part of the object may strike another part before striking any other object.
The Source Object may be placed independently from the parent object. To superimpose the Source Object on the parent object, set the reference object of the Source Object to the parent object (see "Reference objects" ) and leave the position and tilt values at zero.
The parameters are:
| Parameter # | Definition |
| 1-5 | See " Parameters common to all source objects " . |
| 6 | Parent Object #. The integer object number of the object used to define the source shape. This object number must precede the object number of the Source Object in the NSC Editor. |
| 7 | Chord Tolerance: The chord tolerance determines the position accuracy of the starting point for the rays, and affects the rendering of the source. To render or trace rays from the source, OpticStudio converts the imported file to a list of triangles which approximate the shape. The tolerance is the maximum allowed distance in lens units between a single triangle and the actual surface of the source. More triangles are added if the tolerance is set smaller which yields more accurate rendering, at the expense of speed and a larger memory requirement. The default value of zero will use a chord tolerance related to the size of the object sufficient for most purposes. |
| 8 | Cosine Factor: The cosine power exponent "x" described above. |
Use with LightningTrace
This source type is not supported by LightningTrace.
Next: