I was able to come up with my own answer for this. For others looking to do the same, I would suggest modifying the code the following way:
if abs(n(1)*(a-pt3(1))+n(2)*(b-pt3(2))+n(3)*(c-pt3(3)))<1
Due to the size of the 3-D matrix A being rather coarse, 512x512X11, setting the original statement ==0 would only likely include a single stack of points in a column instead of a plane. By increasing the value, the width of the plane increases to encompass and capture more points that can be displayed.
Hope this is helpful...
