Function plan_point_transfer 

pub fn plan_point_transfer(
    bytes: &[u8],
    request: &MeshTransferRequest,
    rgba: &[u8],
    points: &TransferPointPayload<'_>,
) -> Result<MeshTransferPlan, String>

RGB point-cloud source (#4381). rgba carries only the target’s existing rasters; positions, colours and optional normals/stations arrive in points.