[URGENT] Possible Bug: VRayLight Incl/Excl not working with VRayFastSSS2-Shader

[Art48]

Hi,

I might have found a bug. I managed to reproduce it in a very simple scene (attached).

I got a Groundplane (Plane), a Box and a Sphere laying on top of it. (Tested with both sphere and box having their lowest point on the same Z-Height as the Plane, slightly above, and slightly below it.)
I got 1 VRayLight (type "Plane") above the objects illuminating them. The Light is set to include only the sphere.

If I assign all three objects a neutral gray VRayMtl the include works fine.
If I assign all three objects a VRayFastSSS2 material it breaks the include, illuminating all three objects.

I thought maybe the SSS effect scatters the light through the sphere onto the floor and thus being a "feature" and not a bug since in that case the sphere would be illuminating the floor and not the light. Anyways this shouldn't be intended behaviour I guess. Bad thing is we're currently in production of a scene which relies very heavily on the SSS material and we need the include/exclude bug sorted out ASAP (or need a workaround until fixed).
If I missed something here and this is all logical behaviour I still think it should not be that way.

Software Info:
VRay 3.00.04 (Planning to upgrade to 3.00.06 or even 07 the next days/weeks, still waiting for bug reports on these versions , maybe this bug is even fixed?)
3ds max Design 2014 SP3

Bug_SSS_Incl-Excl.zip

I just found out what is apparently causing this: A single-sided surface! If I give the plane a thickness it works fine.
Anyways this shouldnt be intended behaviour since the plane is excluded and shouldnt do anything at all, even if open geometry.

[Art48]

I just found out what is apparently causing this: A single-sided surface! If I give the plane a thickness it works fine.
Anyways this shouldnt be intended behaviour since the plane is excluded and shouldnt do anything at all, even if open geometry.

[matanov]

Thanks for the pointer, it will be reported to our developers, but don't you think that the point of the SSS materials is to be applied on objects with actual volume ?

[Art48]

Hi,

Thanks for the quick response and yes, I totally think so. See, in my case I got a little small-scale mountaineous landscape as my groundplane and was using the SSS shader to a little snowy feeling especially on the small ridges. I didn't think I had to actually close the volume down there since its not my usual approach on modelling landscapes and I thought it will work fine since the SSS effect is subtle and only really visible on the ridges.