setvertexgroup
int setvertexgroup(int geohandle, string name, int prim_num, int vertex_num, int value, string mode="set")
geohandle
A handle to the geometry to write to. Currently the only valid value is 0 or geoself, which means the current geometry in a node. (This argument may be used in the future to allow writing to other geometries.)
To use a linear vertex index, set the prim_num to the linear vertex number and set vertex_num to -1. Note that this is different from how most other vertex functions work.
name
The name of the group to modify.
prim_num
The number of the primitive containing the vertex you want to add/remove.
vertex_num
The vertex offset on the primitive of the vertex you want to add/remove.
value
1 to put the vertex in the group, 0 to remove the vertex from the group.
This is ignored if mode is "toggle".
mode
Use "set" to set the vertex’s membership according to the value.
Use "toggle" to toggle the vertex’s membership, regardless of the value.