Function VisualServerSingleton.multimeshCreate
Creates a new multimesh on the VisualServer and returns an RID
handle. This RID will be used in all multimesh_*
VisualServer functions.
Once finished with your RID, you will want to free the RID using the VisualServer's freeRid
static method.
To place in a scene, attach this multimesh to an instance using instanceSetBase
using the returned RID.