Surfacing - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 174

that is 1 × 1 × 1 units, but has size values of 20 × 20 × 20, Blender textures it as though it were 20 times
its original size. What does this result in? A 1 × 1 × 1 cube with 20 times as much texturing stuffed onto
its surface, or very tiny textures.
With that in mind, you might be wondering how best to scale your textures: Use the Size slider on the
individual texture style's panel (stucci, wood, etc.) or the texture mapping Size x , y , and z controls on the
Mapping panel? Generally, I try to keep the Size control on the style panel to such a level that I can see
what's going on with the texture in the Preview panel. Make it too small and it will just look like grain;
too large, and you won't get a representative sample. So, use the style Size control to get yourself a good
preview. Then use the mapping Size controls to set the proper scale for your scene.
For the walls in the example scene, a series of test renders indicate that a Size setting of around 50.0 for
x , y , and z gives the proper look, without any weird artifacts.
One final note on texture sizes. When creating objects with fine detail, like these walls, it's important not
to make your textures too small. At some point every texture will appear like little more than noise if it
is reduced too much. When this happens, it will ruin animation rendering. Blender's renderer does its best,
but as too much texture detail is packed into a single pixel on each frame, the resulting colors are essentially
random, which causes the texture to appear to “crawl.” Check out crawling_walls.mpeg in the Web Bucket
for an example of the effect. When you see this in your own animations, the cause is always the same:
Your texture is too small. There are two solutions. The first is to increase the apparent size of the texture,
rendering two consecutive frames to see if the crawling effect disappears. The other is to enable Full
Oversampling in the Options panel on the material (not the texture). This causes the renderer to use a
much more exacting method of determining texture colors. It takes a lot longer to render, but if your
scale is truly set and you're unwilling to change it, this is the only way forward.
So far in our wall example, we have selected a procedural texture (stucci) and set its properties, selected
a mapping (Generated), and adjusted the size of the texture space (to 50.0). Now, we have to decide what
aspects of the material the texture is going to affect.
If you'll recall from earlier in the chapter, we said that surfaces usually vary in three ways: color, shine,
and roughness. Let's take a look in the Influence panel of the texture. In all, there are 14 different mate-
rial properties to which we could apply this texture. Most of them (like mirror, emit, etc.) are inappropriate
in this case. The three “must-haves,” though, are Diffuse Color , Specular Intensity, and Geometry
Normal . These account for color, shine, and roughness. Unless there is a compelling reason to do oth-
erwise, you should always have some sort of texturing applied to each of these channels. The rest are
bonuses, and somewhat unnecessary excepting special situations. Failure to texture on these three channels,
though, will result in images that lack believability.
To make the texture affect the Diffuse Color, enable the checkbox beside Color in the Diffuse section of
the panel (it should actually already be enabled as the default). The control doubles as a slider, allowing
you to select the amount of the texture's color that affects the main material color. In these sliders 1.0 is
the same as 100%, so leaving it at 1.0 (the default) results in the texture's color completely replacing that
of the main material. If you were applying wallpaper or some such, this is exactly what you would want.