Each effect instance should be used with geometry of a matching vertex format. Only a subset of effect instance parameters is relevant to geometry of a particular vertex format. If the vertex format does not specify vertex color ( VertexPosition or VertexPositionNormal ) the following parameters should be set:

• Color
• Transparency

If the vertex format specifies vertex normals ( VertexPositionNormal or VertexPositionNormalColored ) the following parameters should be set:

• Ambient Color
• Diffuse Color
• Specular Color
• Glossiness (specular exponent)
• EmissiveColor
• Transparency

If the vertex format specifies a color, then the geometry will be colored according to the color of each vertex. Otherwise, the geometry's color will come from the effect instance parameters. Similarly, the transparency parameter affects all of the geometry associated with the effect, while the transparency of the individual vertices can also be controlled via the transparency component of their colors.

System Object
Autodesk.Revit.DB.DirectContext3D EffectInstance