Creating a Ray File Source

The following procedure helps you define a Ray File Source to be used in a simulation.

Note: Standard ray file format (.ray), standard IES TM25 ray file format (.tm25ray), as well as LightTools® and TracePro® ray file formats (.ray) are compatible with the Ray File Source and can be used to describe the emission of a light source.

To create a Ray File Source:

Important: In case you want to add the source in a Direct simulation, make sure that all parts of the source are enclosed in one single body, or in one ambient material, and therefore are not located in two (or more) bodies or ambient materials. Otherwise you may generate propagation errors.
  1. From the Light Simulation tab, click Ray-file .
  2. To import the ray file, click in the file field and click Browse to select a *.ray or a *.tm25ray file.
    The file is imported and the flux is inherited from the file.
  3. If you do not want to inherit the flux values from the ray file:
    1. From the drop-down list, select False.
    2. From the Type drop-down list, define the flux as luminous or radiant.
      Note: Flux expressed in Watt (W) is the radiant energy or radiant power of a light-emitting source.

      Flux expressed in Lumen (lm) is the luminous flux or luminous power of a light-emitting source.

    3. In Value, specify the luminous flux (lumens) or electric power (watts) of the source.
      Note: If only one flux type (radiometric or photometric) is available in the ray file, you cannot select another flux type.

      If you define an old ray file that does not contain values in lumen, you cannot change the flux unit. To convert the file to a more recent file format, use the Ray File Editor to get values in lumen.

      When loading a ray file, it may not be optimized. In this case, right-click the Ray File source in the tree and click Ray file optimization . If the ray file does not contain any spectrum information, the option will not display until you define the spectrum of the source.

      Ray files generated during a Direct Simulation are automatically optimized.

  4. In the 3D view, set the Axis System of the source by clicking to select one point for the origin, to select a line for the X axis, to select a line for the Y axis or click and select a coordinate system to autofill the Axis System.

    The X and Y directions define the propagation direction of the rays.

    Note: If you define manually one axis only, the other axis is automatically (and randomly) calculated by Speos in the 3D view. However, the other axis in the Definition panel may not correspond to the axis in the 3D view. Please refer to the axis in the 3D view.

    If you need to adjust the ray's propagation direction, set Reverse direction to True.

  5. If the ray file does not contain any spectrum information, define the Spectrum of the source:
    • Select Monochromatic to set the unique Wavelength of the source.

    • Select Blackbody to set the Temperature of the source in kelvin.

    • Select Library and from the drop-down list, click Browse to load a *.spectrum file.

      If you want to see the file properties or edit the file, from the drop-down list, click Open file to open the Spectrum Editor.

  6. If you want to associate geometries to the ray file source, click and select body or face(s) in the 3D view to be considered as the exit geometry of the source.
    The geometries selected appear in the Exit geometry list.

  7. In Optional or advanced settings , adjust the Number of Rays and Length of rays to display in the 3D view.

The Ray File Source is created and visible both in the Simulation panel and in the 3D view.

Tip: Sometimes, to save simulation time, it is useful to split a simulation in two parts. The first simulation can be dedicated to simulate the light propagation in parts with a definitive design (for instance the filament, the bulb and the socket of a lamp). The second simulation can be dedicated to simulate the light propagation in parts currently in the design process (for instance a reflector). You can create a Ray File source with a ray file generated by the first simulation. Then, you can use the ray file source to replace the first part of the optical system in the second simulation. At each simulation done to optimize the second part of the optical system, the simulation time dedicated to the ray propagation in the first part is saved. Generally, with this tip, you can save between 20% and 80% of the simulation time.