I made some "scripts" to help me control my scene before rendering.
for exemple :
$*.wirecolor = black
for bbb in objects where bbb.primaryVisibility == off do bbb.wirecolor = red
so, I can control in viewport if objects will be or not seen by cam.
I would like to do this with VrayAlphacontribution and so on...
but I don't really even understand where to search in Vray docs...
AND I would like to be able to overwrite temporarily object materials with wirecolor, so I could see solid color not just wires.
If anybody find this usefull... :-)