Light Sources

GMPT, October 2024

Brief

  In computer graphics, light source models and optical properties of materials can be simplified significantly. This is because the primary goal of computer graphics is to create visually clear and realistic images, with a high emphasis on rendering speed, while physical accuracy is of secondary importance. However, in the simulation and design of optical systems, adherence to physical laws is essential for achieving physically accurate simulations.

  We use the design of light sources in the software to illustrate the concept of deconstructing and recombining optical properties of various optical elements in the optical system. In optical simulations, light sources can be abstracted as a combination of ray distribution definition and geometric entity modeling. The ray distribution definition uses models or Rayfile files to specify each ray’s origin, direction, relative power, wavelength, and polarization. The materials and optical properties attached to the geometric entity model simulate the effect of a real light source or lamp on the rays as a physical object. As the characteristic size of an optical system becomes larger relative to the light source, the influence of the light source’s geometry and near-field distribution on the final simulation results diminishes. Therefore, light sources can be simplified based on a balance between modeling complexity and simulation efficiency.

Light Source Model List

  In Rayzen, light source definitions range from simple to complex as shown below:

• Light Sources
  • Virtual Light Sources
    • Point Source
    • 2D Area Source
    • Volume Source
    • Data Source
    • 3D Area Source
  • Physical Light Sources
    • 3D Area Source with Additional Material and Optical Properties