Optics Workbench

Geometrical optics for FreeCAD.
Performs simple raytracing through your FreeCAD objects.

Installation

Manual Installation

cd ~/.FreeCAD/Mod/ 
git clone https://github.com/chbergmann/OpticsWorkbench.git

When you restart FreeCAD, "Optics Workbench" workbench should now show up in the workbench dropdown list.

Getting started

• Create some FreeCAD design objects. For 2D simulation Sketches will do the job.
• Select one or more of your design objects and then create Optical Mirror to let your objects act as mirrors
• Select one or more of your design objects and then create Optical Absorber to let your objects act as black walls for the light rays
• Select one or more of your design objects and then create Optical Lenses to let your objects act as lenses. Lenses should be closed shapes. Select a material in the Lens properties or provide a refraction index.
• Add some source of light (Ray, Beam).

Tools

Ray (monochrome)

A single ray for raytracing
Parameters:

• Power: On or Off
• Spherical: False=Beam in one direction, True=Radial or spherical rays
• BeamNrColumns: Number of rays in a beam per row
• BeamNrRows: Number of rays in a beam per column
• BeamDistance: Distance between two beams
• HideFirstPart: Hide the first part of every ray that comes from the source and goes to the first point of reflection/refraction/nirvana
• MaxRayLength: Maximum length of a ray
• MaxNrReflections: Maximum number of reflections. This prevents endless loops if the ray is inside a mirror box.

Ray (sun light)

A bunch of rays with different wavelengths of visible light.
The rays overlap. If they hit a lens, they will be dispersed. See the Example - Dispersion.

2D Beam

A row of multiple rays for raytracing
Parameters: see Ray. BeamNrColumns must be > 1 to get a beam

2D Radial Beam

Rays coming from one point going to all directions in a 2D plane
Parameters: see Ray. BeamNrColumns must be > 1 and BeamNrRows=1 and Spherical=True to get a radial beam

Spherical Beam

Rays coming from one point going to all directions
Parameters: see Ray. BeamNrColumns and BeamNrRows must be > 1 Spherical=True to get a spherical beam

Optical Mirror

The FreeCAD objects in parameter Base will act as mirrors
Select some FreeCAD objects, then create Optical Mirror

Optical Absorber

The FreeCAD objects in parameter Base will swallow the rays of light
Select some FreeCAD objects, then create Optical Absorber

Optical Lens

The FreeCAD objects in parameter Base will act as lenses
Select some FreeCAD objects, then create Optical Lens
The Refration Index has to be provided. The parameter Material contains a list with pre defined refraction indexes.

Switch off lights

Switches off all Rays and Beams

(Re)start simulation

Switches on and recalculates all Rays and Beams

Example - 2D

generates the screenshot above

Example - 3D

Example - Dispersion

Issues and Troubleshooting

see issues on Github

Discussion

Please offer feedback or connect with the developer via the dedicated FreeCAD forum thread.

License

GNU Lesser General Public License v3.0 (LICENSE)