通过给出圆度因子使边缘在visNetwork中弯曲

Question

以下R脚本创建了一个visNetwork图，如图所示。如何通过给出弯曲因子手动将直边改为弯曲边缘？

我在这里尝试使用圆度属性的一种方法，使用＆＃34; smooth＆＃34;标签。但是，无法实现它。

library(visNetwork)
nodes <- data.frame(id = 1:3,color = c(rep("blue",1), rep("red",1), 
rep("green",1)))
edges <- data.frame(from = c(1,2,3), to = c(2,3,1))
nodes = data.frame(nodes, level = edges$from)
visNetwork(nodes, edges, height = "500px", width = "100%") %>% 
visOptions(highlightNearest = list(enabled = T, degree = 2, hover = T)) %>%
visOptions(highlightNearest = F, nodesIdSelection = F, width = 500, height = 
500,autoResize = F) %>%
visHierarchicalLayout() %>% 
visEdges(shadow = TRUE,
       arrows =list(to = list(enabled = TRUE, scaleFactor = 2)),
       color = list(color = "black", highlight = "red"),
       smooth = list(roundness = 0.3))