Sets or adds a vertex normal to the list. If [index] is less than [Count], the existing vertex normal at [index] will be modified. If [index] equals [Count], a new vertex normal is appended to the end of the list. If [index] is larger than [Count], the function will return false.

Sets or adds a normal to the list. If [index] is less than [Count], the existing vertex normal at [index] will be modified. If [index] equals [Count], a new vertex normal is appended to the end of the list. If [index] is larger than [Count], the function will return false.

Sets or adds a vertex normal to the list. If [index] is less than [Count], the existing vertex normal at [index] will be modified. If [index] equals [Count], a new vertex normal is appended to the end of the list. If [index] is larger than [Count], the function will return false.

Sets or adds a vertex normal to the list. If [index] is less than [Count], the existing vertex normal at [index] will be modified. If [index] equals [Count], a new vertex normal is appended to the end of the vertex list. If [index] is larger than [Count], the function will return false.