Fast "Translucent Shader" like material in VRay???

[RSF]

Hello.
I'm using speedtree for an exterior scene but since leaves are billboards facing the camera when sun is on the back the tree leaves look to dark.
I tried using fill lights but the result wasn't that good so I'm trying to give leaves some translucency.
The prblem is that "translucent Shader" doesn't work when rendering with VRay.
Is there a way to have a similar material that renders fast in VRAy and that can be applied to a plane?
Thanks

[J_Bug]

If they weren't billboards you could use the VRayMat. For this though you might want to try the Backlight plugin.

--Jon

[Dynedain]

actually, with speed tree you can use vray mat, just convert the speedtree materials to vray materials

[J_Bug]

Will it look right with the leaves being billboards facing the cam and not modeled?

--Jon

[Dynedain]

when it billboards, it just uses opacity maps i believe so i would think so

[RSF]

Thanks.
The Backlight plugin worked well in VRay althought the result wasn't that good.
As for VRay translucency I haven't played much with it but I think it only works on volumetric objects...I think...

I have an outdoor scene with about 3000 trees...not counting with the ones outside the plan area

SpeedTree seamed good for this situation because it renders fast enought, I can look at them from above, have random seed and I also prefer the somewhat simplified tree than a foto.
The problem is really the "counterlighting" (sorry...don't know the english expression) since the leaves are always facing the camera (with a small angle variation). I think speedtree as methods for controling lighting and LOD also but they're not imlpemented in the 3dstudio plugin
Well...Any tips are very wellcome
Thanks again

[Dynedain]

but I think it only works on volumetric objects...I think...

Nope, it works fine with planar objects. Vlado did an example a while back of using translucency to achieve some very good water effects with just some planar-type objects generated from dreamscape I believe.

As for the "counter lighting" i'm not sure what you mean. But when I use speedtree, I normall convert the speedtree materials to Vray materials, then increase my lighting and turn on the HSV exposure control and it brings the colors back into the useable values.