规则示意
attr ErkerFact = 0.8
attr ErkerDepth = 0.8
attr ErkerStop = 2
Lot–>
extrude(10)
X
comp(f) { all : Erker }
Erker–>
case(scope.sx > ErkerStop) :
s(‘ErkerFact, ‘ErkerFact, 0)
center(xy)
alignScopeToGeometry(yUp, 0)
extrude(ErkerDepth)
X
comp(f){top : Erker}
else:
NIL
视频教程请参考
原文：http://blog.51cto.com/eyearth/2124907