strange behavior on rotation (and transparency)

[GoogleCodeExporter]

What steps will reproduce the problem?
1. I have a surface model (a bit like the terrain you show in the demos) which 
depicts walls on bare soil. When I rotate the model, the walls seems to 
disappear (the same that would happen if I rotate it upside down). I guess the 
link to the file will explain better.
http://politeia.ims.forth.gr/en/temp.php
2.
3.

What is the expected output? What do you see instead?
Walls should not "disappear" when rotating

What version of the product are you using? On what operating system?
I downloaded the very last JS from the repository

Please provide any additional information below.

Original issue reported on code.google.com by gianluca...@gmail.com on 29 Aug 2014 at 6:43

[GoogleCodeExporter]

Sorry, I just found the problem!
It was an issue with the normals of the surface.
Sorry to bother you and thanks for the grate script.
G.

Original comment by gianluca...@gmail.com on 29 Aug 2014 at 6:57

[GoogleCodeExporter]

I'll publish a new release soon, which will introduce a new startup parameter 
'FaceCulling' to specify whether back-face culling is enabled in rendering. I 
think this provides convenience to fix such problems. Please keep an eye on the 
new release :-)

Original comment by Humu2...@gmail.com on 29 Aug 2014 at 11:37

[GoogleCodeExporter]

Thanks!
This would be indeed a great add-on.
Sorry if I ask you that here, but is there a way to produce cross-sections of 
the model?
Thanks

Original comment by gianluca...@gmail.com on 29 Aug 2014 at 11:48

[GoogleCodeExporter]

I'm afraid not. Additional codes are requested to implement such feature.

Original comment by Humu2...@gmail.com on 29 Aug 2014 at 12:53