R中的平滑3D三角形网格

我正在绘制人脸的3D表面网格。可以在https://github.com/Patricklv/Smoothing-3D-surface上找到数据，其中vb.xlsx包含顶点，it.xlsx包含面。

我的R代码如下：

library(xlsx)
library(rgl)

vb <- read.xlsx("C:\\Users\\<Username>\\Desktop\\vb.xlsx", sheetIndex = 1, header = F)
it <- read.xlsx("C:\\Users\\<Username>\\Desktop\\it.xlsx", sheetIndex = 1, header = F)
vb_mat <- t(as.matrix(vb))
vb_mat <- rbind(vb_mat, 1)
rownames(vb_mat) <- c("xpts", "ypts", "zpts", "")

it_mat <- t(as.matrix(it))
rownames(it_mat) <- NULL

vertices <- c(vb_mat)
indices <- c(it_mat)

try <- tmesh3d(vertices = vertices, indices = indices, homogeneous = TRUE, material = NULL, normals = NULL, texcoords = NULL)

shade3d(try, ambient = "darkgrey", specular = "white")

最终的3D曲面如下：在3D曲面网格上很容易看到很多三角形。我想使此surace网格看起来更平滑，就像下面显示的那样：

What should I do in R to smooth the surface mesh so that the mesh looks like the second one, where visible triangular faces are smoothed out? Perhaps Phong model for shading would work through contour3d function in misc3d package. Can anyone show how this function could be applied to my data?

I noted that the plotly package in R has some pretty handy ways to create surface mesh:

library(plotly)

face <- plot_ly(
    x = vb[,1], y = vb[,2], z = vb[,3],
    type = "mesh3d"
)

face

The resultant facial surface mesh is as below:

The surface mesh is very smooth! But I cannot control the orientation of the plotly.js object when saving it. Neither could I save it as PDF file without additional purchasing. I wish to know how plotly did the magic to create this smooth surface mesh, even when I did not provide face information (it information not provided, only vb provided)? If the magic done by plotly can be done in some other manner in R so that I can customize the orientation when saving pictures and can save it as PDF file without purchasing, while still maintaing such high level of smoothness?