`curve.pointAt(ratio [, opt])`

Return a point on the curve that lies `ratio`

(normalized length) away from the beginning of the curve.

The function expects `ratio`

to lie between 0 and 1; values outside the range are constrained to 0 and 1, respectively.

This function mirrors the functionality of the `line.pointAt()`

function. If the point at a given `t`

value is needed instead, use the `curve.pointAtT()`

function.

The function uses the same algorithm as the `curve.pointAtLength()`

function.

The default value for `opt.precision`

is 3; this corresponds to maximum observed error of 0.1%.

The `opt.subdivisions`

property may be specified, directly providing an array of pre-computed curve subdivisions from which to calculate curve length. Use the `curve.getSubdivisions()`

function to obtain an array of curve subdivisions. The `opt.precision`

property is still necessary, however; it determines the precision of the point search algorithm.