shadows projected in rhinoceros

[susanna.pata]

hello to all, I have a problem with shadows in my model 3d.
I created a surface from the ground level curves and then projected the curves on the surface and extruded the buildings. I would like to study shadows but I can't get the shadows projected on the ground.
I have already done everything I knew to do and found as a solution, that is:
- check 'shadows' from the display menu
- Activate rendering mode
- set solar incidence values from the 'toggle sun panel' by 'render tools'

How can I solve this?thanks in advance
(I attach photos)

 

[Tristus]

could help you this:http://ctrl-z.it/studio-delle-ombre-rhino/

 

[susanna.pata]

could help you this:http://ctrl-z.it/studio-delle-ombre-rhino/

thanks tristus but I had already opened that page. is explained very well but also performing everything to the letters nothing... .