Need help creating frosty materials

[dj_buckley]

Just looking for advice and different approaches to creating 'frosty' materials.  Snow is fine, it's making things look frosty that I'm struggling to figure out.  I need to create a winter scene, where everything has started to frost over, grass, fences etc.  Anybody tackled this before?  Everything I've researched has returned scenes/images covered in full snow.  Here's a few examples of what I'm trying to achieve

https://wobblybike.files.wordpress.com/2012/01/p1020608.jpg

https://www.google.co.uk/search?q=frosty+grass&source=lnms&tbm=isch&sa=X&ved=0ahUKEwib26W67sbYAhUmI8AKHTJjA5YQ_AUICigB&biw=1920&bih=949#imgrc=W9vd_sMsS48PhM:

http://www.yellow-teddy.org.uk/diary/diary-12-2/Hewitts-Farm-frosty-grass-1211-0162-yellowteddyorguk.jpg

https://thumbs.dreamstime.com/b/autumn-morning-landscape-first-frost-yellowing-lonely-tree-river-55257447.jpg

Thanks in advance

[maru]

Such frost is definitely a complex phenomenon. Here are some ideas for a simplified version:
Use layered mtl. Put the basic grass material as the base material. Then add some simple white material as layer 1 (probably with some reflectivity, maybe with some translucency).
Then mask the white material with a falloff map. I am attaching two approaches:
1) Just the falloff map, set to the default "perpendicular/parallel"/viewing direction
2) Falloff map, set to "perpendicular/parallel"/World Y-Axis, plus some tiny noise displacement added to the base map.

[dj_buckley]

Wow looks awesome, are you able to share the scene?

[maru]

Unfortunately not, but the material setup is super simple. Something like this:

[dj_buckley]

No worries, it's that falloff curve I was looking for :)

[dj_buckley]

Unfortunately not, but the material setup is super simple. Something like this:

Can I ask why 'World Y Axis'?

[maru]

If Y is not the vertical axis, then it is a mistake. :)

[PROH]

In max the World Y-axis is never vertical :) That's the world Z-axis.

[mferster]

Although having the falloff on the side kinda makes sense, as long as that side faces the sun.

[dj_buckley]

Thanks for the clarification

[maru]

I made that test very quickly and I just picked the axis randomly while looking at the IR window and decided it's that one when it looked good enough. I admit that it may be a mistake.

[dj_buckley]

It's cool, I think I've got it, only issue I'm having now is I can't get any displacement/bump to work on the frost material to give the impression of 'particles' rather than just a flat white material

[davemahi]

It's cool, I think I've got it, only issue I'm having now is I can't get any displacement/bump to work on the frost material to give the impression of 'particles' rather than just a flat white material

I think you can't have any displacements other than the base material. I really wish this was not the case.

[romullus]

I think you'd get better results with some flakeish normal map rather than displacement.

[dj_buckley]

Yep just discovering this, not working in anything other than base, also found another post confirming this as a known limitation.  The workaround being, copying the falloff that defines the blend, into the displacement slot of the base material, and then putting your displacement map in the relevant slot.  Becomes problematic though if the base material already has displacement