FMP: Materials in UDK 1

I've been working on my Materials in UDK - creating a decent set of master materials so I can make variants of them and apply to my meshes.

Paramitors & Controllers
The main thing I found with master materials is to have the appropriate variables/controls you might want to change over different meshes.  So you want a "peramiter" to select different texture maps for starters.  Then you might want controllers to change the tiling, contrast or colour balance maybe.  You can very simply invert a channel for example (common in correcting normal maps from different applications), or tint a diffuse.

Here is an early version of a multi-layered material

Blending maps

Blending maps are grey-scale, and depend from asset to asset on what you want to blend together.  Most map blending will be connected to the height or its features - the cracks may have grime/foliage gather, the outer corners may get worn and corroded with age.  Because of this it is a good idea to create height maps, & cavity maps.  I have been stowing these in the alpha of my diffuse maps.

Multiple Layers
By using tiling textures you can add the impression of detail.  Say I have a standard material I can then tile textured detail on it.  Below is an example of layering rock textures 

Here I changed the tiling and intensity of a second normal map to add appropriate detail

Vertex Painting
Vertex Painting is pretty cool - Apparently every vert already has colour information so vert painting is "free" -resource wise.  I think it is great as you can add variety where there would otherwise be none - Breaking up the uniformity & repetitiveness of game engines - is pretty new gen.  For these blending layers to work though you really need a "blending mask" or two.

I will be using a main material to create most objects.  The foliage and others will require different materials.

Here is a variant of the material - with a second normal map and vertex painted moss

Here's a screenshot of the nodes in the material editor - Is too much as a whole, even though it is organised it is big, & a little confusing to look at

...Pretty confusing?!

There are little tweaks I may do - like adding an option for the "mix" normals to be ignored - at the moment he moss overides the rocky texture which is not what I fully want.