Thank you for hearing me out.
In the old bootleg 3.7 version of vray, there was a snow shader that acted like a triplaner with only the -Y directions. This was pretty useful for the dusted snow effect. you could also use it as a mask for bump I believe. I think maybe it had noise for the falloff too?
anyhow, thanks for your time.
Hello @wolfgang_himmelfarb Thank you for contacting us. Please, keep in mind that from V-Ray 5 the software has been rewritten from scratch and many of its features work differently than in V-Ray 3.7, some has been removed entirely.
One way to do this now, apart from using a texture map, is with V-Ray Decal - by placing it over the geometry you want it to affect you can add a white texture with Bump as well.
@wolfgang_himmelfarb I think you can get similar results with the Terrain Mask shader. this is a native c4d shader that works with vray. it’s under effects!
thanks for the heads up. I did not consider it but I give it a try and I think bc its based on the uvw I’m not getting the right results. Appears to use local coordinates but im needing global mapping - something like a triplanar. I’m actually on another thread trying to work that angle as well. Decal might be my only workable option but when considering a big complex environment this way, seems very messy considering it could be an opacity mapped “mix material”
@wolfgang_himmelfarb I see. This is a bummer. I Thought that the terrain mask could work. There is a global coordinates tick box in the shader but i don’t think it does anything atm. maybe this is a bug? Also the terrain mask direction is defo not working with vray.
the old snow shader we did in 3.7 was nothing more than a preset for a falloff shader in world coordinates. you can use a vray falloff or even c4d fall off to get exact the same as in 3.7 (edit: as in Siros examples)
I have falloff working now and the effect will work, but I recall a turbulence(noise) parameter in 3.7 as well, that was confined to the falloff itself - not a mask but would displace the falloff at the transition, if that makes sense.
…if i’m being picky, falloff still treats poly objects separately. I suppose a projection would probably be the most convincing. Anyhow, THANKS EVERYONE FOR THE HELP 
yes right, this you can easy make in using a mix or layer shader to add a noise to add extra variation.
as said it was nothing that isnt there now. only difference is you need to set it up yourself one time.
if i find some time i can maybe share a simple example
