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Ray trace settings using ZOS API in python

  • 26 January 2023
  • 2 replies
  • 179 views

Hi all,

I have been using ZOS-API Pythonnet to perform a ray trace and save the ray trace data as text files. The following program snippet worked perfectly fine up until a few months ago. Now, when I run the same code, it does the ray trace and saves the text file without changing any of the settings.

import ZOSAPI;
TheSystem = TheApplication.PrimarySystem;
teleFile=('T_file.zmx')
TheSystem.LoadFile(teleFile,False);
Systemdata=TheSystem.SystemData

TheAnalyses=TheSystem.Analyses;
X, Y = np.round(np.mgrid[(-1):(1):100j, (-1):(1):100j],3)
positions = np.vstack([X.ravel(), Y.ravel()])
pos=np.transpose(positions)
px=pos[:,0]
py=pos[:,1]
max_rays=len(px)
newWin=TheAnalyses.New_Analysis(ZOSAPI.Analysis.AnalysisIDM.RayTrace);
newWin_Settings=newWin.GetSettings();
Field_1 = Systemdata.Fields.GetField(1)
Field_1.X=0
Field_1.Y=0
path='\RT_trial'
for i in range(max_rays):
    newWin_Settings.Px=px[i];
    newWin_Settings.Py=py[i];
    #newWin_Settings.Wavelength.SetWavelengthNumber(1);
    #newWin_Settings.Field.SetFieldNumber(1);
    newWin_Settings.Type=ZOSAPI.Analysis.Settings.Aberrations.RayTraceType.DirectionCosines;
    newWin.ApplyAndWaitForCompletion();
    newWin_Results=newWin.GetResults();
    file_name=path+'ray_'+str(i)+'.txt'
    newWin_Results.GetTextFile(file_name)

The Px and Py =0 for all the rays in the text files. Does anyone know what the issue could be? 

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Best answer by MichaelH 27 January 2023, 20:12

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2 replies

Userlevel 7
Badge +2

Hi Ramya,

 

Assuming your code doesn’t have a bug, what’s your Python and Pythonnet version? There have been issues recently with version of Pythonnet > 2.5.2. If you are in this case, can you install Pythonnet 2.5.2 and try again?

Take care,

 

David

Userlevel 6
Badge +2

Hi Ramya,

If the script is actually able to run to the end but you just don’t see anything change, then I think pythonnet is correct, however please take David’s advice and ensure you’re not using pythonnet 3.0.

You might not have copied the entire script, but I don’t see where you initialize the type of connection from the zosapi module (zosapi.App() or zosapi.Interactive()).  So assume you have the proper connection to OpticStudio in another part of the script, I think you might be failing around lines 3-4; the LoadFile is looking for a full file path.  The default LENS.ZMX file which is loaded in OpticStudio has 0 aperture size, so I always like to add the following code immediately after a TheSystemLoadFile() command:

import zosapi

zos = zosapi.App()
TheSystem = zos.TheSystem
TheApplication = zos.TheApplication
ZOSAPI = zos.ZOSAPI

fullfilename = r'c:\user\Documents\Zemax\file.zmx'
TheSystem.LoadFile(fullfilename, False)

# this checks to make sure a valid file was loaded
if TheSystem.SystemData.Aperture.ApertureValue == 0:
raise SystemError('The Aperture Value is "0". Please ensure the filename is valid')

# rest of code goes below here

Also, unless it’s absolutely necessary, I would suggest simplifying how you generate your px/py values; there is no reason to use mgrid, vstack, revel, or transpose.  Since the pythonic way is to keep it simple, I would simply use 2 for loops (you can do this with a simple range but numpy already has the ability to normalize the coordinates with linspace):

n = 100
x = np.linspace(-1, 1, n)
y = np.linspace(-1, 1, n)
for px in x:
for py in y:
# make sure the ray is inside the pupil
if px*px + py*py <= 1:
# run code

 

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