Terrains and Landscapes in Un real Engine 481
of this expression is a value between 0 and 1, for each instance of the mesh on
which th e material is applied. The value is calculated as a ratio between the Start
and End Cull Distances set up in the Foliage System.
If the instance is closer to the camera than the Start Cull Dista nce, the
value for the Per Instance Fade Amount will be 1 . If the instance is farther
than the End Cull Dis tance, the value for the Per Instance Fade Amount
will be 0. The value ranges from 1 to 0 as the instance goes from the Start
Cull Distance to End Cull Distance.
If we multiply the o utput of the Per Instance Fade Amount with the Alpha
channel of our Texture Sa m ple (as shown in Figure 7.56) and supply the result
to