Icy/Frosted surface?

[Monogon]

Hello V-Ray Users,

I was hoping to get some ideas on how to create a icy/frozen effect like in the attached images. (Maybe something in between those two..)

Tried a little around with displacement but so far the max standard noise maps didn't get me very far.
Any procedural maps you would recommend for stuff like that? I am also trying to figure out the best way to control density and size of the tiny icycles

Any idea is welcome, also the cheap fake workarounds

Felix

[joconnell]

Use a really agressively colour corrected noise and also look into the falloff map in towards away mode - if you use world z you're going to get a nice mask for the parts of the model facing upwards only!

[Monogon]

Thx joconnell. Falloff might not be an option since we will have a moving camera around the geometry.

[joconnell]

Since it's world based rather than camera angle it'll work for objects that don't animate or deform, Another alternative is something like forest pack or pflow to scatter loads of tiny little spiky flake objects with a vray fast sss material on them!

[M.Max]

I second what Joconnell suggest ..you can also use Local Z if your object is going to be transformed .but even if it is going to be deformed you can easily bake it and use it as a bitmap mask .
you can combine that with cavity/dirt maps to avoid showing this effect in concave areas and some noise./smoke/ cellular or even bercon noise and custom maps to break the cgi look ..that's for the mask .
for the icy\frost itself I might try to combine both bump for small details-displacement for larger details and finally scatter these tinny spikes on top of that .
VRayScatterVolum ,V-Ray AL Surface can help here but it depends on the lighting and how close is your object to camera you might get away with simple vraymtl and save days of rendering : ))
would love to see how you will tackle this so please keep us updated

[Monogon]

Thx guys, will look into that. I there a good way to blend everything displaced into a separate material while using the objects xyz coordinates instead of a map channel? would like to stick to objects coordinates avoid distortions from unwrapping..

[joconnell]

Falloff and noise maps are procedural so don't rely on your uvs at all, the particle approach will be millions of tiny models stuck on to your mesh and will use their own local mapping and the direction of the surfaces that they're stuck on!