Snow pine needles

[james adamson]

Hi all.
I have some xfrog pine trees which I am trying to add a bit of a snow effect to.
I have gone into the shader network for the population. (tgo files.) And have added a surface layer under the shader for the pine neeedles that came with the 
xfrog file.
In the RTP preview I get something that looks correct but when I render the image it looks totally different. I have changed the diffuse setting in the tgos shader
and that works on its own. i.e I get more of the colour of the actual needle but the surface layer which is supposed to be adding the snow does not seem to be rendering correctly. Or rather it is and I am doing something wrong. 
Stills attached.
Thanks in advance.
James.

[Dune]

The RTP review is rough and maybe not taking light and GI into account, and the render is what counts, so I'd work on that. This should work in principle, but I'd add a PF with smallscale bluish white variation and set that to world scale (through transform shader). Also some translucency, and reflection.
So best would be to add a default shader (taken through transform [world] shader) as child of that surface shader (breakup can go), and use those settings (very light blue-white variation, some translucency, reflection and maybe some luminosity). With the surface shader you can use masking by altitude (use final and Y) or PF, or whatever.

[james adamson]

Awesome.
Thanks Dune.

[james adamson]

So just to be clear. Keep the network as is but delete fractal breakup shader and add a default shader as a child of the surface layer?
And what do you mean when you say taken through transform(world) shader and what is the purpose of that transform?
Ta.

[james adamson]

And although my trees are tiny in the actual scene. Its an arial shot. I would like the needles to have some specular quality.
So the default shader is the way to go? I was playing with the settings of the shader that came with the tgo file and had the image map of the pine needle. This is the wrong way to go about what I am trying to achieve?

[Dune]

Answer to your first question; yes. Maybe the transform shader isn't needed, but it makes the fractal adjust to world scale instead of UV scale (but then again, this maybe isn't important here).
The default shader has inbuilt reflection, translucency and luminosity, so that's why I use that.
You can also replace the needle color UV map by a whitish map, then you can add the translucency and reflection and luminosity in the first default shader, and forget about that added as child one.
Or merge two default shaders, one with white needles, one with colored needles. Merge by a controller like altitude (distribution shader) or PF (world space).
Just work on one tree in a new file and experiment with all possibilities until you get something you want, then save as tgo, and open as pop in the big file.

[james adamson]

Great. 
Thanks.

[james adamson]

Thanks for those tips Dune. I used your suggestion of painting up a white version of the needle texture and blending two versions of the tree and it worked a treat.
Cheers.

[Dune]

Good to hear that.