Textures in Blender Render
Now let’s look at the Texture tab and its main features, so you can proceed to the next part of the chapter and start using all this information to actually shade your character. Figure 10.2 shows the Texture tab and its panels.
The following list describes the basics of what you can do in each one of these panels:
Current selection: Similar to the Material tab, clicking the Pin icon produces a list of the current objects/materials/textures on which you’re working. You can use the Pin exactly as you would in other editors and, at the bottom of this panel, you’ll find three little icons to select the type of texture you want to work on.
The first icon (the World) uses a texture, the second one lets you work on the textures for the current material, and the third one lets you create textures for things like brushes.
Textures list: This panel works similar to layers. You can select one of the slots and then create or load a texture for that slot. You can load another texture in the next slot and make it transparent; then you’ll see the first texture behind it. Similar to modifiers, the top layers are beneath those that appear at the bottom of the list. This panel is not only used for layers, but it can also contain different textures affecting various properties of the material.
Current texture: The current texture’s name and drop-down list work exactly the same as they would for any other datablock. Right below the name, you can find a list from which you have to select the type of texture you’re going to be using inside this slot. In this case, Image or Movie is selected, as it’s the one you’ll need when you want to load your own images to use as textures for the materials. The rest are procedural textures. The other panels on the Texture tab can change a little depending on the type of texture you select in this panel.
Preview: In this panel, you can see what the current texture looks like and decide if you want to see the texture, the material, or both.
Colors: This panel shows several options that will change the image’s colors. Options such as Brightness, Contrast, or Saturation will change how the image looks.
Image: The Image panel is specific to the Image or Movie texture type. It basically gives you some options to load an existing texture or to create a texture generated by Blender, as you’ve seen in Chapters 8 and 9 (such as a UV Test Grid).
Image Sampling: This important panel shows options that tell Blender how to interpret the image you’ve loaded. Interpreting the alpha of an image, for example, is one of the things you’ll determine with the Image Sampling options.
Tip
If you want to use Normal maps, you should activate the Normal Map option in the Image Sampling panel and select the type of Normal map you want (usually it’s Tangent).
Image Mapping: In this panel, you can offset, resize, and crop the image you’ve loaded into Blender or repeat it over and over beyond its boundaries.
Mapping: Not to be confused with Image Mapping, this panel lets you define how the image is “mapped” onto the object. If you’ve unwrapped the model to which you’re applying this material, you should pick UVs from the Coordinates drop-down list.
Influence: Remember what you learned about channels earlier? Well, this panel is where you select which channels of the material are affected by the current texture, as well as the amount of effect the texture has. You can see that, by default, the texture is affecting the Color (Diffuse) channel only. If you have a Normal map loaded, for example, you should disable Color, and in the Geometry section, enable Normal to define its effect. If you have a black-and-white image, you can turn on Ray Mirror to define the reflectivity of the material.
Let’s say you want to mix two different images together: you can load them in different Texture slots and adjust the influences in their respective channels. Also, you can even change the blending mode (by default, Mix) just as you would change the layers blending modes in Photoshop or Gimp.
You can also use a mask. If you enable the Stencil option, the current texture will be used as a mask for the next slot in this editor. Combinations of options can really expand your choices!
Tip
Usually, you may need to load a texture with alpha (like a .png image) and you need to use that alpha as the transparency in Blender. This can be kind of tricky if you don’t know how to do it, so here are two steps to make this operation straightforward:
1. Activate Transparency for the material (Z Transparency or Raytrace) and, in order to give the power to the texture, set the Alpha of the Transparency option in the material to 0.
2. Load your image, including the alpha, enable its Alpha influence, and set it to the maximum. The material will now use the alpha from your image.