public void SetNextVertex(Vertex vertex)

Vertex

Used to iteratively fill the values of the allocated vertices via repeated calls to this function until all values have been provided. This way of filling vertex data is mutually exclusive with the use of MeshWriteData.SetAllVertices. After each invocation to this function, the internal counter for the next vertex is automatically incremented. When this method is called, it is not possible to use MeshWriteData.SetAllVertices to fill the vertices.

Note that calling MeshWriteData.SetNextVertex fewer times than the allocated number of vertices will leave the remaining vertices with random values as MeshGenerationContext.Allocate does not initialize the returned data to 0 to avoid redundant work.