Better blending between multiple nodes of the blobtree

A blobtree is an implicit surface defined by a tree of objects. Each node of the tree can either be a primitive or an operation. Primitives are skeletal implicit surfaces defined by a skeleton (like a point or a line) and a potential function which maps the distance to the primitive to R. Operations (like union, twist or blend) are nodes that work on one or more other nodes. Skeletal implicit surfaces are volume representations particularly useful for models which require smooth blending. In some cases problems arise when blending is used. One of those problems occur when the nodes involved in the blend have large differences in their blending ranges. In this case the influence of the relatively small node is negligible compared to the larger ones. Because of this, in certain places the result will look more like a union then a blend. The method presented in this paper deals with the previous problem, even in the cases where multiple nodes (either primitives or operations) are used. The idea behind this method is to locally deform the blending ranges of each node in order to make the blending conditions between each pair of nodes more suitable for smooth blending.