Copyright c©2003 Institute of Electrical and Electronics Engineers, inc. All rights reserved.
1
Rendering Artistic and Believable Trees for Cartoon Animation
Fabian Di Fiore
William Van Haevre
Frank Van Reeth
Limburgs Universitair Centrum
Expertise Center for Digital Media
Universitaire Campus
B-3590 Diepenbeek, Belgium
E-mail: {fabian.difiore, william.vanhaevre, frank.vanreeth}@luc.ac.be
Abstract
We present a novel approach to design artistic and be-
lievable trees in a cartoon-like style, which can be rendered
by an animated camera to produce a convincing 3D-like ex-
perience. While computer assisted traditional animation is
able to generate the desired effects, this approach still de-
pends too much on the creation of many hand drawn im-
ages. Existing approaches fully depending on 3D geome-
tries, on the other hand, give little artistic freedom and
have difficulties to avoid artifacts popping up in successive
frames.
In order to provide good solutions to these difficulties, we
present a hybrid (2.5D) framework, combining the advan-
tages of both 2D and 3D approaches. From an underlying
3D geometry we get the necessary information to obtain an
acceptable level of 3D behavior and a good frame-to-frame
coherence. In the same framework, 2D artistic input is em-
ployed to obtain any desired ‘look’, both of the rendering
and of the animation.
Keywords: natural phenomena, 2.5D animation, com-
puter animation, non–photorealistic rendering.
1. Introduction
During the last years, the use of CGI elements in the pro-
duction of cartoon animations has become a very common
thing. This paper deals with the category of CGI effects
which classifies the CGI standards: things that are too nu-
merous or tedious to draw. In our case, the animation of
cartoon-like trees. Figure 1 shows some snapshots of the
kind of animations we are striving after.
Consider for example figure 1. From an animator’s point
of view two technical issues arise. The first issue concerns
the animator’s ability to picture in mind the objects he is
(a)
(b)