As shown in Figure 3(a), freehand figure sketching is essentially
rough and imprecise, which contains various “noises” –
wiggly/overlapping strokes, missing figure contour, asymmetrical
body parts, etc. To turn this sketchy 2D figure into 3D
sophisticated mesh model, sketch clean-up needs to be performed.
Figure 3 illustrates how a freehand figure sketch undergoes
automatic processing and graphical comparison, to be morphed
gradually (both “biologically” and geometrically) into a plausible
3D human body model (details in another paper). During this
process, an “auto-beautification” option is also offered to
regularise an asymmetrical sketch-generated model (see Figure
3(c)). Meanwhile, users can interactively refine the resulting 3D
model by over-sketching its 2D figure profiles (see Figure 3(d)).
Modifications can be made at any time, and on any key frame
sketch, to achieve the updated 3D model. In addition, a postprocessing
function is also provided for varying an existing figure
model, by changing its body proportion.
Beyond a flat drawing medium, it will be ideal to provide users
with an interactive and mixed modelling environment, in which
they can sketch 2D figure, “pop it up” into a 3D character, and
incrementally refine it through suggestive contours [29],
shading/shadow, etc, in both 2D and 3D. Having realized the
sketch-based figure fast prototyping, the implementation of other
features will be our next challenge