The textured forest looks pretty bad when it does not have shading- It is pretty much impossible to distinguish different trees other than on horizons-
|Textured Forest, no shading|
Luckily implementing dynamic shading is not too difficult, and a variety of shading techniques can be combined to create a convincing effect.
Terrain Shading – trees will be shaded in shadow of terrain contours
lighting factor writen to Forest Map – passed through Displacement Filter
Height Shading – Assuming trees are shaded more on the bottom -
Forest Height is determined by texture height * forest Value in terrain Vertices
Forest Value passed through Forest Map –
bottomShading = finalHeight/ForestValue (Relative Max Height)
|Emboss Bump Map Shading|
Embos Bump Mapping – Technique used to approximate bump mapping – may still show up in terrain shadows-
Combined Shading – Shading methods multiplied together- some artifacts from embos bump map..
These shading methods require 2 more channels to be passed through the initial mapping process- Relative height for height shading and a light factor calculated for the emboss and terrain shading