Optics Workbench

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

Installation

Auto Installation

Optics workbench is available through the FreeCAD Addon Manager

Manual Installation

Expand to view manual installation instructions

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

Important Note

Once Optics workbench is installed, FreeCAD will need to be restarted. 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
After a ray or beam has been added, a parameter 'Hits From Ray/Beam...' will appear. This is a counter of how many reflections you have from each ray. Do not modify this value.

Optical Absorber

The FreeCAD objects in parameter Base will swallow the rays of light
Select some FreeCAD objects, then create Optical Absorber
After a ray or beam has been added, a parameter 'Hits From Ray/Beam...' will appear. This is a counter of how many rays have hit this absorber. Do not modify this value.
'Hit coordinates from ... (read only)' records the position of each LIGHT RAY when it hits. This way, it is possible to visualize the image on the absorber in a XY diagram.

To show an XY plot, open a python console and type:

import OpticsWorkbench
OpticsWorkbench.plot_xy(App.ActiveDocument.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.
After a ray or beam has been added, a parameter 'Hits From Ray/Beam...' will appear. This is a counter of how many refractions you have from each ray. Do not modify this value.

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)

hoba87/OpticsWorkbench