Highly stylised animation
Author(s): Fabian Di Fiore, Frank Van Reeth, John Patterson, Philip Willis.
Article: The Visual Computer, Vol. 24, No. 2, pp. 105--123,
2007.
[BibTeX] [DOI] 
Abstract:
In this paper we argue for our NPAR system as an effective 2D alternative
to most of NPR research which is focused on frame coherent stylised rendering
of 3D models. Our approach gives a highly stylised look to images without the
support of 3D models, and yet they still behave as though animated by drawing,
which they are.
First, a stylised brush tool is used to freely draw extreme poses of characters.
Each character is built up of 2D drawn brush strokes which are manually grouped
into layers. Each layer is assigned its place in a drawing hierarchy called a Hierarchical
Display Model (HDM). Next, multiple HDMs are created for the same
character, each corresponding to a specific view. A collection of HDMs essentially
reintroduces some correspondence information to the 2D drawings needed for inbetweening
and, in effect, eliminates the need for a true 3D model.
Once the models are composed the animator starts by defining keyframes from
extreme poses in time. Next, brush stroke trajectories defined by the keyframe
HDMs are in-betweened automatically across intermediate frames. Finally, each
HDM of each generated in-between frame is traversed and all elements are drawn
one on another from back to front.
Our techniques support highly rendered styles which are particularly difficult
to animate by traditional means including the 'airbrushed', scraperboard, watercolour,
Gouache, 'ink-wash', pastel, and the 'crayon' styles. In addition, we describe
the data path to be followed to create highly stylised animations by incorporating
real footage.
We believe our system offers a new fresh perspective on computer aided animation
production and associated tools.