Removes any spikes from a geometry.
A spike is defined to be three consecutive points (A, B, C) such that:
the distance AB is less than the distance BC
the sine of the angle ABC is less than a maximum value which may be specified by the second parameter
(Optional) the distance AB is less than a maximum "length" value specified by the third parameter
For each such spike, the vertex B will be removed.
Parameter 1 - any geometry.
Parameter 2 (Optional) - the maximum value for the sine of the angle in the spike. If omitted, this defaults to the sine of 1 degree.
Parameter 3 (Optional) - the maximum length of the spike.
Returns: the resulting geometry with spikes removed or null if parameter 1 is not a geometry.
Note: This function does not fully support 3D geometries. Any 3D geometries will be projected down to 2 dimensions.