2.6.3 Can you answer these questions?

2.6.3.1 Creating a certain image (3D shadows, highlighted intersections)

http://mathematica.stackexchange.com/questions/92494/creating-a-certain-image-3d-shadows-highlighted-intersections

 
I would like to learn how to code within Mathematica the following picture: 
 
 
 
I tried using 
 
planarShadow[x_, direction_, normal_, darkShadow_: True] := 
Module[{d, n}, d = Normalize[direction]; 
...
 

- asked by boldbrandywine 5votes

2.6.3.2 How to stop auto loading of previously opened notebooks

http://mathematica.stackexchange.com/questions/92699/how-to-stop-auto-loading-of-previously-opened-notebooks

 
I'm trying to prevent Mathematica from opening previously opened notebooks when I start it up. I'm using version 10.0.0.0 on Mac OS X Yosemite. I've dug around in the preferences, and have tried  ...
 

- asked by Peter Wills 2votes

2.6.3.3 Visualising a 1-(50,15,15) design

http://mathematica.stackexchange.com/questions/92605/visualising-a-1-50-15-15-design

 
The problem I have is the visualisation of a $1-(50,15,15)$ design. That is a set of $50$ points and $50$ blocks (lines), so that each point is on $15$ lines, and each line contains $15$ points. 
 
My  ...
 

- asked by user32681 4votes

—