thank you thomthom to be so patient, (I'm tired: too much work).
I've tried rendering in parallel view and naturally NOW it works, also in photo matching...except in the only one that I needed. I can't divulgate it because it's a contest.
The Vray version is 01.05.30.
3- I use sun light source with the parameters in the attached image.

("charmo" means nothing in italian, but I don't care about it)

comunque grazie per le numerose risposte, buffoni

I've three questions about Vray:
1- How can I obtain a rendered image of a viewport in parallel view mode such as front view or axonometric view?
2- How can I obtain a rendered image of a viewport with matched image (in the tag of the viewport name it appears "(2D)" suffix), I suppose it's a camera setting problem...
3- How can I obtain smooth shadows without rough appearance like the attached image?

thanks

than you, sometimes Ithink I'm little s....d

I've the material editor like the attached image.
Why must it be double? Is it right?

thank

Hi,
can you explain the "protractor/rotate-copy/subdivide method" ?
thank you

excuse me but I'm working on a big model of a '700 baroque
villa in Turin with a lot of colums and with garden ground up and down and it is possible I'm not understandable!
I agree: the material editor preview is not reliable.
what I mean is:
-the material editor preview is uncorrect (dark)
-the final render is ok (with trasparent material also to the backfaces)
-I'd like to know how to assign a material to backfaces in a simple way (the method I've tried seems tedious (I don't explain it because it is tedious)
-my english is not suitable for a BBC documentary about Vray...

ok it works fine thank you!
but the rendered material in the material editor is still darker
(sse attached image).
How can I assign material to backfaces?

thanks again

when you turn the transparency lower tahn 20%
in SKP, vray renders it no more transparent and a lot darker. Also if you
modify the transparency map in the Vray material editor.
I've found it happans around 20% of transparency.
i've got the 01.05.30 version of Vray

do you know anything about the transparent material problem?
thx