Parameters
- partIndex
- Zero-based index of the part to split. Last part is PartCount - 1.
- distance
- The distance from the start point of the part to insert the vertex.
- asRatio
- True to treat the distance as a ratio (or %) of the part length.
- createPart
- (Optional) Specifies whether a new part is to be created when the part is split. For polygons, it is always set to false. The default value is false.
Return Value
The index of the segment that was split. It is relative to the part.
If the split didn't happen, -1 is returned.