Having trouble with matte properties in glasses.

[tayrona]

Hello, I am having trouble with matte objects. I usually set mattes in vray properties, checking "matte object" alpha contribution -1, and checking "shadows" and "affect alpha".

 

I expect that objects with this options avoid the visibility of other objects behind them acordding the refraction, for example if the matte object use a 0% refraction material, then nothing is going to be visible behind it, but if matte object use a 50% refraction material, then, objects behind will be 50% visible.

 

My problem is that all objects works the same... as if they have 0% refraction and glasses are not working as glasses.

 

Is there any option I am forgetting?? My glass material is simple: difusse: light blue color, reflection 35, refraction 225, affect shadows checked and in "affect channels" I am selecting: color+alpha (I am using max 2010 + vray sp4a).

 

Thanks in advance for any help.