As Mats pointed out on my blog, the VRay2sidedmtl doesn’t seem to work as one would expect. In the image above (same one attached as well) I don’t understand why the back side shows through even though there is no illumination on the back. (I tried with secondary bounces off too - same result). It seems you need to keep the rgb values for the translucency map under about 100 for it to work as (i think) it should.
Here are my tests; everything seems to be ok. In the first two images, the light is above the plane; in the third and fourth image, it is below. The front material is green, the back is red, both with a circle for opacity map. A Noise map in turbulence mode is used for the translucency slot.
thanks for taking the time to look into it Vlado, I misunderstood how vray2sidedmtl works i think. I assumed it there wouldn’t be any translucent effect if there was no light hitting the back side of the material.
I have to admit that I am having problems with the 2-sided material too. I find it behaves strange if you have 2 different materials for front and back. I am trying to use it for a lamp shade that has 2 different materials on front and back but the back material shines through even if the light inside the lamp isnt switched on. If you turn translucency fully on (white), then the back material becomes the front material and vica versa. When would that ever happen in reality?
So is it just a case of being careful with the translucency values? In my test above I found that rgb values of approx 0-100 work OK for things like leaves and paper.