#### 3.6.2 The Materials Panel

The Materials panel controls material properties of surfaces. It works with the target object in the same way that the Appearance panel does.

Figure 3.7: The Materials Panel.

Transparent
  This button determines whether transparency is enabled. Geomview itself does not fully support transparency yet and on some machines it does not work at all. (The missing piece is implementation of a depth-sorting algorithm in the rendering engine; not difficult, but just not done yet.) Use RenderMan if you want real transparency: when transparency is enabled, a RenderMan snapshot will contain the alpha information.
Alpha
  This slider determines the opacity/transparency when transparency is enabled. 0 means totally transparent, 1 means totally opaque.
Diffuse Reflectance
  This slider controls the diffuse reflectance of a surface. This has to do with how much the surface scatters light that it reflects.
Shininess
  This slider controls how shiny a surface is. This determines the size of specular highlights on the surface. Lower values give the surface a duller appearance.
Ambient Reflectance
  This slider controls how much of the ambient light a surface reflects.
Specular Reflectance
  This slider controls the specular reflectance of a surface. This has to do with how directly the surface reflects light rays. Higher values give brighter specular highlights.
Done
  This button dismisses the Materials panel.