LightSampling

The LightSampling command is an RWX Command that sets the light sampling type of the current material.

Usage

    LightSampling value

Description

This command sets the light sampling type of the current material. Valid light sampling types are either facet or vertex.

Facet-based light sampling (the default) means that each polygon is lit individually by the light source(s) in the world, with a "hard edge" visible from one polygon to the next if the polygons face in different directions. Use facet-based lighting when you want boundaries between the individual polygons making up the object to be visible, for example if you are making an object with lots of right angles, such as a cube.

Vertex-based light sampling causes polygons to be lit continuously from one polygon to the next, so that the surface appears "smooth" and the boundaries between polygons are not visible. Use vertex-based lighting when you are using polygons to approximate a smooth surface, such as a human face.

It should be noted that facet-based light sampling is less efficient than vertex-based light sampling and can lead to substantially lower frame rates on complex objects. The reason for this is that facet-based lighting requires each polygon to have its own private set of vertices whereas vertex-based lighting allows polygons to share vertices.

Arguments

value is the light sampling type which is either facet or vertex

Examples

LightSampling facet # this is the default

LightSampling vertex # this smooths the edges of the model

The following code shows how a model can be segmented by rendering part of it smooth and the other part not. This can be useful when the model has both curves and rectangular sections that need to be rendered differently.

 modelbegin
  protoinstance model1
   lightsampling vertex # <--- vertex
   # model code here
  protoend
  protoinstance model2
   lightsampling facet # <--- facet
   # model code here
  protoend
  clumpbegin
   protoinstance model1
   protoinstance model2
  clumpend
 modelend