Game Development and Simulation with Unreal Technology

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