wine glass-coplanar surfaces- which is the correct method?

[giraffe]

Hello
I am a bit confused as I remember some long time ago I saved this image from forum- showing right method to render coplanar surfaces.
(image in the attachment)

And on vray help page it is shown in the tutorial as :


I felt a little confused and wanted to ask.

[zeronove]

I remember the attached image as coming from mental ray help files; for me the Vlado suggestion worked fine, maybe the other is the way to go only if using MR

[MasterBercon]

VRay manual explains it clearly. Read the general section: http://www.spot3d.com/vray/help/150S...sinterface.htm

[giraffe]

thanks so much
the attached image comes from this forum- but I saved it some long time ago.
and I read that tutorial today.
that is why I felt confused. I couldnt decide if tutorial or the image from forums is more old dated

[RErender]

In the olden days, early 1.09 days I think, the attached example was what worked, you needed to separate the surfaces and adjust the ior's but somewhere along the way Vlado updated the way vray calc's the interface to make it easier so that now it works by just overlapping the volumes.

[giraffe]

Thanks for the explanation Rerender
I remember this drawing and explanation well too- that is why I couldnt be sure.
Now with your explanation, understood all the history