Basic Mixed Forests

 So far the forests rendered in this prototype have all been the same type.  Luckily, it is not too hard to allow for multiple types of trees to be represented with this approach.

Canadian Boreal Forest - Deciduous, spruce and pine trees

 So far this model only contains two types of trees, but many more could be added easily.  Different tree types may have different max height,shape, color, and texture.  The following processes provide a rough implementation for mixed forests.

Height Map rendering with mixed forest.

Essentially the type of tree is defined by the shape and color in the forest map.

Forest Height Map, Type defined by blue channel

Here the blue Chanel is used to define smaller deciduous trees.  Where there is blue, the height and offset values are modified in the pixel shader to generate the Forest Map.  The Offset chanel is already used as the x value when sampling the final forest textur, so it is scaled down by the number of tree types, and then offset depending on the value of the tree type.

Here the forest texture is divided into two images, texture and color, each split to represent two different tree types.  The y coordinates of the color texture image represent the decay value so the color of tress can change smoothly. 

Mixed Forest, deciduous trees have higher decay value.