The mapping function <!-- MATH $w=k\log(z+a)$ --> <i>w</i> =
<i>k</i> log(<i>z</i> + <i>a</i>) is a widely accepted approximation
to the topographic structure of primate V1 foveal and parafoveal
regions. A better model, at the cost of an additional parameter,
captures the full field topographic map in terms of the
<i>dipole map</i> function <!-- MATH $w=k\log[(z+a)/(z+b)]$ -->
<i>w</i> = <i>k</i> log[(<i>z</i> + <i>a</i>)/(<i>z</i> + <i>b</i>)].
However, neither model describes topographic shear since they are both
explicitly complex-analytic or conformal. In this paper, we adopt a
simple <i>ansatz</i> for topographic shear in V1, V2, and V3 that
assumes that cortical topographic shear is rotational, i.e. a
compression along iso-eccentricity contours. We model the constant
rotational shear with a quasiconformal mapping, the <i>wedge
mapping</i>. Composing this wedge mapping with the dipole mapping
provides an approximation to V1, V2, and V3 topographic structure,
effectively unifying all three areas into a single V1-V2-V3
<i>complex</i> using five independent parameters. This work represents
the first full-field, multi-area, quasiconformal model of striate and
extra-striate topographic map structure.