yshear about the origin  2d and 3d transformations
Suppose an object point P(x,y) be moved to P'(x',y') in the xdirection, through the specified scale parameter 'b'. that is, P'(x'y') be the result of yshear of point P(x,y) through scale factor 'b' regarding the origin, that is demonstrated in Figure 5(a).
Figure: 5(a)
Hence, the points P(x,y) and P'(x',y') have the subsequent relationship :
x' = x


y' = y+bx

= Shy(b)

Here 'b' is a constant (termed as shear parameter) which measures the degree of shearing. In matrix form, we contain:
In terms of Homogeneous Coordinates, above equation (16) is:
There is, P'_{h} = P_{h}.Sh_{y}(b)
Here P_{h} and P'_{h} represents object points, before and after needed transformation, in Homogeneous Coordinates and Sh_{y}(b) is termed as homogeneous transformation matrix for yshear along with scale factor 'b' in the ydirection.