Answer by Graham Dunnett

The [docs][1] that you have read ;-) say that the third argument to `SendMessage()` is a `SendMessageOptions` type. I guess the compiler is having problems working out how your un-typed `hitpos2` can be converted into one of those. You seem to use `hitpos2` as if it was a `Vector3`. [1]: http://docs.unity3d.com/ScriptReference/GameObject.SendMessage.html