Leaky Triangulated Box
========================


Summary
-------

Shooting millions of photons at triangulation edges is 
fount to let some thru.  The solution is to 
avoid doing that eg by shifting targetted point to avoid cracks
or use analytic box instead.


Initial Observation
-------------------------


BoxInBox Pyrex block in Vacuum lit by spherical focus light targetting single point::

   ggv.sh  --test --save \
        --eye 0.5,0.5,0.0 \
        --animtimemax 7 \
        --testconfig "mode=BoxInBox_dimensions=500,300,0,0_boundary=Rock//perfectAbsorbSurface/Vacuum_boundary=Vacuum///Pyrex_" \
        --torchconfig "polz=spol_frame=1_type=refltest_source=0,0,300_target=0,0,1_radius=102_zenithazimuth=0,0.5,0,1_material=Vacuum" \
         $*


Rec.py seqhis selection 

* TORCH BR SA : one reflection then gets surface absorbed  
* TORCH BR AB : one reflection then bulk absorbed


Some 6 percent miss the target::

    In [78]: pos1[:,2]
    Out[78]: array([ 299.997,  299.997,  299.997, ...,  299.997,  299.997,  299.997], dtype=float32)

    In [91]: pos1[pos1[:,2] != pos1[0,2]].shape
    Out[91]: (4728, 3)

    In [82]: p1z
    Out[82]: array([ 299.997,  299.997,  299.997, ...,  299.997,  299.997,  299.997], dtype=float32)

    In [83]: p1z[p1z<299]
    Out[83]: array([ 12.009,  47.792, -18.876, ..., -15.503, -42.802,  68.941], dtype=float32)

    In [87]: 4728./82600
    Out[87]: 0.05723970944309927