9.5.2

964 • CHAPTER 18
TEXTURE MAPPING • 965
Mixing textures
CINEMA 4D lets you use as many materials and Texture tags on an object as you like. Think of a suitcase
with travel stickers — there is a base material (i.e. the leather of the suitcase) and many materials on
top (i.e. the stickers).
Naturally, you won’t be able to see the suitcase leather under the stickers. Also, suppose some of the
stickers overlap. A sticker will, naturally, cover any stickers that it is on top of.
To see one of the stickers underneath such a sticker, you’d have to peel off the top stickers. Or scratch
holes in them!
This analogy can be related closely to CINEMA 4D’s behavior. Your object has a base material. You
have additional materials on top of the base material. In order to see the base material, the overlying
materials must be scaled down and not tiled. You can do this by scaling down the texture geometry
and at the same time disabling the Tile option. If two materials overlap and you want to see the bottom
one, you must make a hole in the top one. You can do this using the alpha channel or clip mapping.
So how does CINEMA 4D know which layer a material is on?
When you apply several materials, each new material is placed on top of the previous one. Thus the
order of the Texture tags in the Object manager denes the order of the layers — the right-most
Texture tag in the Object manager is the top layer, the left-most is the bottom layer. You can change
the layering order simply by swapping the positions of the Texture tags using drag and drop.
The Transparency material property does not allow the next layer to
show through. Instead, use materials with alpha channels or clip mapping
(genlocking).
Figure 1.
Suppose we’re creating a wall of bricks, on which there is a poster and some grafti. We’ll use a
material with a color channel and a bump channel for the bricks, a plastic-like material for the poster
(which is scaled down with no tiling) and a grafti material that will have an alpha channel so that
the bricks and poster show through the writing. See Figure 1, above.