The separation of
these two modeling tasks makes the whole process highly flexible and powerful,
and from a conceptual point of view easier to handle. While generally good
for many classes of objects, this two-step process is nevertheless prone
to problems when the geometry of the object is complex and therefore the
mapping of visual characteristics to every point of the surface is non-trivial.
Another potential drawback of this approach is that it implicitly assumes
that there is no interplay between the two processes which define the shape
and the visual attributes of an object. For some objects, however,
the visual aspect is the result of a process where there is an interaction
between the two and this interaction plays a significant role on the final
result. Typical examples are patterned animals such as giraffes and leopards,
where the pattern visible on the fur of an adult animal is the result of
a much earlier process which took place while the animal was in the womb.
In this case to model the interplay between the embryo growing and the
pattern formation process is as
important as the
modeling of the individual processes themselves.
In this work we introduce a novel way for approaching these cases whereby the visual attributes are defined directly on the surface of the object and, more importantly, where we take into account the dynamic change of shape undergone by the object because of growth or other reasons. Finally, we also advance the notion of integration of independent tools as an important development in the field of computer graphics. Individual tools have been reaching exceptional levels of performance and therefore we need efficient ways to integrate them smoothly.