Materials in practice

In this section we will analyze how to set up the various material parameters in Blender, and what you should expect as a result.

Once an Object is selected by pressing the F5 key or the material buttons window appears (Figure 4). Of these buttons, the left block (Figure 5) is strictly relevant to material shaders, while the right block is relevant to material textures and will be analyzed in the pertinent section.

Figure 4. Material Buttons.

Figure 5. Material Buttons strictly pertinent to material shaders.

In this block the leftmost sub-block presents the material preview. By default it is a plane seen from the top, but it can be set to a sphere or to a cube with the buttons on top of the preview window (Figure 6).

Figure 6. Material Preview, plane (left) sphere (middle) and cube (right).

Material Colours

The next group of buttons (Figure 7) determines the material colours.

Figure 7. Material colours buttons.

Each material can exhibit up to three colours:

The aforementioned buttons select the pertinent colour, which is shown in preview immediately above the button. The three sliders on the right allow you to change the values for the colour both in a RGB scheme and in a HSV scheme. You can select these schemes via the RGB and HSV buttons on the far left.

The DYN button is used to set the Dynamic properties of the Object in the RealTime engine, which is outside the scope of this manual, while the three buttons on the far right are relative to advanced Vertex Paint and UV Texture.

The Shaders

Underneath the colour buttons there are the shader buttons (Figure 8). On the top, the two pop-up menus allow you to select one diffuse shader (on the right, Figure 9) and one specular shader (on the left, Figure 10).

Figure 8. Material colours buttons.

Figure 9. Material Diffuse shaders.

Figure 10. Material Specular shaders.

Below these there are two sliders, valid for all shaders, determining the intensity of the Diffusion and Specular phenomena. The Ref slider has a 0 to 1 range whereas the Spec has a 0 to 2 range. Strictly Physically speaking, if A is the light energy impinging on the object, then Ref times A is the energy diffused and Spec times A is the energy specularly reflected and, to be physically correct it must be Ref + Spec < 1 or the object would radiate more energy that it receives.

But this is CG, so don't be too strict on physics.