Creating a TIR Lens

This page shows how to create a Total Internal Reflection lens.

To create a TIR lens:

From the Design tab, click TIR lens .
A preview of the TIR lens support plane and associated parameters appear in the 3D view.
From the Mode drop-down list, select which parameter should drive the lens' dimensions:
- Select Thickness to define the lens by its height.
- Select Output radius to define the lens by the radius of its output face.
Click and select a point to define the Source position.

Note: The source is considered as punctual.
Click and select plane to define the position of the lens input face (the support).
In Input radius, type a value to define the internal radius of the TIR Lens on the support plane.
In Depth, type a value to define the distance between the support plane and the first intersection with the lens along the revolution axis.
In Draft Angle, type a value to define the revolution axis angle.
In Support thickness, define the thickness of the ring at the bottom of the lens.
Define the Refractive index of the lens.
If you chose Thickness, set a value to define the lens' height, or use the 3D view manipulators.
If you chose Output radius, type a value to define the radius of the lens' output face.
Set the Focal of the lens, that is the distance between the source and the top of the internal collimating surface.
In Spread, type a value in [0° ; 90°[ to define the spread angle of the rays. 0° corresponds to collimated rays.
In Spread behavior, select the spread behavior of the rays:
- Concave: the TIR face spreads from max aperture to 0°, meaning rays are crossing.
- Convex: the TIR face spreads from 0° to max aperture, meaning rays are opening.
In Spread control, type a value in [0 ; 100] to control the light distribution in the target in the range [0 ; Spread Max].
Press F4 to leave the feature edition mode.

The TIR lens is created and appears both in the tree and in the 3D view.