CREATING THE SNOW AND MATERIALS
The snow material is a simple white standard material. I did some tests using an Arch and Design material with sub-surface scattering, but it increased render time without really improving the look of the snow. In the end I did use A&D materials, but only for objects with opacity maps, as A&D’s Cutout works better with Mental Ray than Opacity in the standard material.
I think with this type of lighting (sunset with a low and relatively dim light), the modelling is more important than the shader to make it look believable. Also, using a simple shader was much easier to manage than a complex one. Indeed, as almost all of the objects had at least one snow material on them but with different maps, they had to look exactly the same.
I was not quite satisfied with the snow covering the pine trees in the foreground. There was clearly a lack of details compared to the scale of the trees. I tried to completely remodel the snow using a new selection of leaves and some tweaking in the Blobmesh parameters but that didn’t work out too well. So after testing a couple of possible solutions the best way I found was to use a Landscape shader in the Opacity slot, so when rendering we see only the upper part of the mesh.
Another trick to simulate a snow layer on the trees was to bake a set of lights placed on top of each source tree using Render To Texture. The resulting black and white maps were used as masks in the leaf materials. These maps could have been used for snow displacement, but I did some tests and it took a bit too long to render.
The map for the field and road in the mid-ground were painted in Photoshop, as something specific was needed for this part of the environment. In the background was a satellite view grabbed from Google Maps and edited in Photoshop for contrast, colour correction, adding and suppressing some details here and there. Same for the mountains in the background, with a different map.
Some of the materials used in the scene. Most are very simple standard materials with hand-painted textures. No fancy reflections or sub-surface scattering were needed.
To learn how to create the entire 3D landscape, as well as other tutorials, check out Digital Mayhem 3D Landscape Techniques!
Check out the companion website for even more materials!
Excerpt from Digital Mayhem 3D Landscape Techniques by Duncan Evans © 2013 Taylor and Francis Group. All Rights Reserved.