The formula for curvature of a 2D bezier curve is as follows:
$κ(t)=\frac{|B′(t),B′′(t)|}{||B′(t)||^{3}}$
The dividend is the determinant of two joined vectors (2x2 where each vector is a column), but for 3D, the matrix would not be square, and therefore would have no determinant. Is there a different equation for curvature of a 3D curve? Does one even exist?