I'll tell you about texturing of snow-capped mountains.
I had terrain model ready, It was made for the Sochi 2014 Olympics with the help of Ortholaser technology, and the model was generated in Autodesk Civil. The total size is approximately 10-13 km. There are many methods of terrain modeling, but what about texturing?
The method I found for snow-covered trees
worked fine here! If you haven't seen those lesson - no problem, I have described all in detail here.
Obviously, the complexity of the mountains is that snow should not lie everywhere: it should not be on abrupt parts of mountains.
In 3ds Max the parametric texture, which returns color depending on direction - is Falloff with Towards / Away option. But it alone cannot satisfy us completely, because the gradient, which she returns is too smooth and unnatural. There is a lack of randomness. We can fix this with the help of Gradient Ramp, which adds noise to the gradient, obtained in a Falloff Map. In addition to adding noise, Gradient Ramp further modifies this gradient mask, coming from Falloff.
Let's see this material design from top level to the lower.
1. In the diffuse slot of the material is mix-map is situated which will mix the texture of stone and snow. I used the textures shown.
2. In mixing map slot Gradient Ramp is situated. It must be "Mapped" type.
3. As a map, Falloff map is used, with Towards/Away option (World Z)
4. On the material top level instance copy all this complete map from diffuse to bump slot.
I usually start the creation of such a material with a creation of Gradient Ramp + Falloff bundle in the diffuse slot of a standard material. With a Self-illumination 100 and roughly tune the resulting black / white mask. Then I create a Mix-card (paragraph 1), and put this bundle to the mix amount slot. Self illumination is no longer needed. Be sure to place the instance copy in the bump right now! Then follows a fine tuning of the Falloff curve, gradient and noise in the Gradient Map.
The nuances of setting:
-All maps must use a separate texture channel. For snow and stone it is obvious, but it is important not to forget to put the Gradient Ramp to a separate channel. I used a huge UVW Map Gizmo for this gradient map channel. I do not remember exactly, either 10 or 100 km. Of course it depends on the configuration of the noise. You must do test renders - you won't see this Gradient Ramp map (and it noise) in the viewport, because it was get from falloff map.
- Bump has very strong influence on the material. Bump map modifies the normals, and the Falloff map in diffuse channel reacts to this. It gives excellent results: the snow will lie on smallest ledges on abrupt and vertical parts of terrain. It is very natural. Apparently the render processes diffuse bump before diffuse, otherwise this would not have happened.
- It is noteworthy that the material is parametric. You can rule the degree of snow cover with Mix-curve in the Falloff map, and even animate it to simulate the melt/snow covering.
- This material is not properly previewed in Material Editor . This is natural for such a complex material. Don't be confused.
- Perhaps not everyone knows: the bumpiness degree of texture can be ruled in the Output rollout - Bump Amount. This allow to make the stone more bumpy than snow.
One more example of this material: