correction in documentation, removing checkerboard.png/pov, adding my…

… comments

.gitignore

@@ -1,3 +1,6 @@
+transparency/checkerboard.png
+transparency/checkerboard.pov
+
 *~
 
 # Byte-compiled / optimized / DLL files

transparency/checkerboard_factory.py

@@ -45,7 +45,7 @@ def find_checkerboard(self, n_checks, reflectances=None, sample_repeat=9):
         n_checks : int
             Number of checks in each direction.
         reflectances : list[float] or None
-            Reflectance values for the checks to draw from randomly.
+            Reflectance values [in povray a.u.] for the checks to draw from randomly.
             When None, default values as in Wiebel, Aguilar and Maertens 2017 are used.
         sample_repeat : int
             Repeating >reflectances< this many times, then drawing without replacing.
@@ -76,11 +76,11 @@ def build_image(self, tau, alpha, background=.27, camera_offset=(0, 0, 0), look_
         Parameters
         ----------
         tau : float
-            Luminosity of the transparent partial overlay. [0.0, 10.0]
+            Reflectance [in povray a.u.] of the transparent partial overlay. [0.0, 10.0]
         alpha : float
             Alpha value of the transparent partial overlay. [0.0, 1.0]
         background : float
-            Background luminosity. [0.0, 1.0]
+            Background luminance. [0.0, 1.0]
         camera_offset, look_at_offset : tuple[int]
             xyz coordinate offset from default camera position / look_at focus position
         transparency_coords : list or None, optional
@@ -270,9 +270,9 @@ def write_pov(filename, r_checks, positions, transparency=None, cb_transf=None,
     planes, pointers : list[str]
         list of povray instructions
     background : float
-        background luminosity
+        background luminance
     light : float
-        light source luminosity
+        light source intensity
     camera_offset, look_at_offset : tuple[float]
         xyz coordinate offset from default camera position / look_at focus position
     """

transparency/comments.md

@@ -0,0 +1,14 @@
+23.03.2002 My Comments/ ToDo list:
+
+- decide about how to import. checkerboard_mask.png cannot be found
+- check consistency in indentation, in checkerboard_factory.py is mixed.
+- in README, add instructions to how to install requirements.
+- in example usage, make a one line comment what is happening in each step
+- add plt.imshow() calls, to display the resulting images
+- find_checkerboard() gives error when n_checks^2 > len(reflectances)*sample_repeat. Maybe check that this is not the case, if it is, then increase sample_repeat to min required and warn user
+- get_stacked() returns a tuple with the masks included...
+- with Yiqun with add an additional constrain to the checkerboard sampling: all reflectance values have to be behind the transparency, the same ones but shuffled. Check code and add this option here with a switch to activate this restriction / or not.
+- it's not luminosity but luminance. change accordingly in all documentation, also fn parameters
+- in texture factor, get_image(), alpha is inverted. higher alpha -> more transmissive.
+- missing option of having a regular checkerboard with transparency on top... ?
+- TextureFactory missing the 'stacked' version. maybe both horizontal and vertical stacked?