Added python script for "Ray relaying" example

gallery/ray-relaying.py

@@ -0,0 +1,47 @@
+import numpy as np
+import json
+
+f = 40 # lens focal length
+d = [80,152] # distance between consecutive lenses in each series, respectively
+lensNum = [37,20] # number of lenses in each series, respectively
+lensDiameter = 540
+beamDisplacement = 40 # the light beam is placed horizontally at "beamDisplacement" to the left of the lens series
+beamRadius = 60
+x_origin = 0 # simulation origin coordinates
+y_origin = 0 #
+initial_x = 300 # lenses coordinate displacement
+initial_y = 960 #
+y_displacement = [0,1.5*lensDiameter] # vertical distance between consecutive series of lenses
+
+# initialize the simulation general properties
+Dict = dict()
+Dict['version'] = 2
+Dict['objs'] = []
+Dict['mode'] = "light"
+Dict['rayDensity_light'] = 0.25
+Dict['rayDensity_images'] = 1
+Dict['observer'] = None
+Dict['origin'] = {'x':x_origin,'y':y_origin}
+Dict['scale'] = 0.4
+Dict['colorMode'] = False
+
+# build the series of lenses with the corresponding light beams
+for i in range(len(d)):
+    for k in range(lensNum[i]):
+        Dict['objs'].append({"type":"lens", "p1": {"type": 1, "x":initial_x+k*d[i], # add the k'th lens of the i'th series into the simulation
+        "y":initial_y+y_displacement[i], "exist":True}, "p2": {"type": 1, "x":initial_x+k*d[i],
+        "y":initial_y+lensDiameter+y_displacement[i], "exist":True}, "p": f }) 
+    Dict['objs'].append({"type":"parallel", "p1":{"type": 1, "x":initial_x-beamDisplacement, # add the light beam for the i'th series into the simulation
+    "y":0.5*(2*initial_y+lensDiameter)-beamRadius+y_displacement[i], "exist":True}, "p2":{"type": 1,
+    "x":initial_x-beamDisplacement, "y":0.5*(2*initial_y+lensDiameter)+beamRadius+y_displacement[i], "exist":True}, "p":0.5})
+
+# int32 type is not serializable, therefore convert it to int type
+def convert(o):
+    if isinstance(o, np.int32): return int(o)  
+    raise TypeError
+
+json_Dict = json.dumps(Dict, default=convert) # converts the dictionary to a json formatted string
+
+# create the json (simulation) file
+with open("ray-relaying.json", "w") as f:
+    f.write(json_Dict)