Aiming Area

The following page helps you understand the purpose of the Aiming Area in a Physical Camera.

The Aiming Area is an important notion of the Physical Camera. The Aiming Area is not a parameter to be set but you need to understand its impact in order to correctly define your system and simulations.

Description

The Aiming Area corresponds to the first face of the lens system surrounded by a bounding box. The optimized propagation engine makes sure that rays launched aim to this area. Once rays interfered with the aiming area, the propagation is done following the Monte Carlo algorithm from the Aiming Area.

According to the simulation, the aiming area is different:

  • In case of a Direct Simulation the Aiming Area corresponds to the first face of the lens from the source.

  • In case of an Inverse simulation the Aiming Area corresponds to the first face of the lens from the sensor.



Direct Simulation VS Inverse Simulation

According to the source to simulate you will not use the same simulation type.
  • To simulate an Ambient Source, use the Inverse Simulation.
  • To simulate all other sources, use the Direct Simulation.

When rays generated from the sensor enter the Aiming Area, the propagation is mainly done specularly. That means Speos has no control over the propagation (direction) of the rays afterthat. Therefore, when rays exit the lens system (after last face of the light box used), the convergence will be correct in case of Ambient Sources, but very slow in case of other sources.

Emission Angle of Sources

The sources with an emission angle correspond to the source for which you can define an intensity diagram (Surface, Luminaire, Display).

If a ray launched from the Aiming Area is outside of the emission angle of the source, the ray is lost. If the emission angle is small, the convergence is very slow. We recommend you to convert your source in a Ray File Source as rays are hard-coded.

Input and Output Faces Concept

The Input face and Output face are concepts important to understand.
  • The Input face corresponds to the face from which the rays enter the optical system.
  • The Output face corresponds to the face through which the rays exit the optical system. In other words, the Output face is the first face found by the opposite integration direction of the Irradiance sensor (direction starting from the center of the sensor).

Therefore, that means the last face of the optical system (Light Box) is not necessarily the Output face. Indeed, the Light Box can be composed of geometries that corresponds to the camera body and that are located after the Irradiance sensor.



Both definitions are valid for Direct and Inverse simulations. That means:
  • In Direct simulation, the Aiming area is the Input face.
  • In Inverse simulation, the Aiming area is the Output face.