R 和 RGL：如何为球体添加标签？

Question

请看看下面的reprex。 我使用 RGL 创建一组由段链接的球体。 我希望能够为每个球体添加一个标签（例如一个数字或一个字母），以便能够单独解决它们（例如，如果我谈论球体“4”或球体“D”，应该清楚哪个球体我在说）。

关于如何实现这一目标的任何想法？

谢谢！

library(rgl)
library(tidyverse)


sphere1.f <- function(x0 = 0, y0 = 0, z0 = 0, r = 1, n = 101, ...){
  f <- function(s,t){ 
    cbind(   r * cos(t)*cos(s) + x0,
             r *        sin(s) + y0,
             r * sin(t)*cos(s) + z0)
  }
  persp3d(f, slim = c(-pi/2,pi/2), tlim = c(0, 2*pi), n = n, add = T, ...)
}




agg <- structure(list(X1 = c(-0.308421860438279, -1.42503395393061, 
1.10667871416591, -0.41759848570565, 0.523721760757519, 0.520653825151111, 
4.54213267745731, 2.96469370222004, 6.32495200153492, 3.78715565912871, 
5.35968114482443), X2 = c(0.183223776337368, 1.69719822686475, 
-0.992839275466541, 2.22182475540691, -0.705817674534376, -2.40358980860811, 
-0.565561169031234, -0.362260309907445, 0.326094711744554, 0.60340188259578, 
-0.00167511540165435), X3 = c(-0.712687792799106, -0.0336746884947792, 
0.0711272759107127, 1.6126544944538, -2.29999319137504, 1.36257390230441, 
-1.52942342176029, -0.316841449239697, -1.69222713171002, 1.23000775530984, 
2.30848424740017)), class = c("spec_tbl_df", "tbl_df", "tbl", 
"data.frame"), row.names = c(NA, -11L), spec = structure(list(
    cols = list(X1 = structure(list(), class = c("collector_double", 
    "collector")), X2 = structure(list(), class = c("collector_double", 
    "collector")), X3 = structure(list(), class = c("collector_double", 
    "collector"))), default = structure(list(), class = c("collector_guess", 
    "collector")), skip = 0), class = "col_spec"))


bond_segments <- structure(list(X1 = c(-1.42503395393061, -0.308421860438279, 
1.10667871416591, -0.308421860438279, 0.523721760757519, -0.308421860438279, 
-0.41759848570565, -1.42503395393061, 0.520653825151111, 1.10667871416591, 
2.96469370222004, 1.10667871416591, 2.96469370222004, 4.54213267745731, 
6.32495200153492, 4.54213267745731, 3.78715565912871, 2.96469370222004, 
5.35968114482443, 3.78715565912871), X2 = c(1.69719822686475, 
0.183223776337368, -0.992839275466541, 0.183223776337368, -0.705817674534376, 
0.183223776337368, 2.22182475540691, 1.69719822686475, -2.40358980860811, 
-0.992839275466541, -0.362260309907445, -0.992839275466541, -0.362260309907445, 
-0.565561169031234, 0.326094711744554, -0.565561169031234, 0.60340188259578, 
-0.362260309907445, -0.00167511540165435, 0.60340188259578), 
    X3 = c(-0.0336746884947792, -0.712687792799106, 0.0711272759107127, 
    -0.712687792799106, -2.29999319137504, -0.712687792799106, 
    1.6126544944538, -0.0336746884947792, 1.36257390230441, 0.0711272759107127, 
    -0.316841449239697, 0.0711272759107127, -0.316841449239697, 
    -1.52942342176029, -1.69222713171002, -1.52942342176029, 
    1.23000775530984, -0.316841449239697, 2.30848424740017, 1.23000775530984
    )), class = c("spec_tbl_df", "tbl_df", "tbl", "data.frame"
), row.names = c(NA, -20L), spec = structure(list(cols = list(
    X1 = structure(list(), class = c("collector_double", "collector"
    )), X2 = structure(list(), class = c("collector_double", 
    "collector")), X3 = structure(list(), class = c("collector_double", 
    "collector"))), default = structure(list(), class = c("collector_guess", 
"collector")), skip = 0), class = "col_spec"))


open3d()
#> glX 
#>   1

material3d(ambient = "black", specular = "grey60", emission = "black", shininess = 30.0)
clear3d(type = "lights")
light3d(theta = -30, phi = 60, viewpoint.rel = TRUE, ambient = "#FFFFFF", diffuse = "#FFFFFF", specular = "#FFFFFF", x = NULL, y = NULL, z = NULL)
light3d(theta = -0, phi = 0, viewpoint.rel = TRUE,  diffuse = "gray20", specular = "gray25", ambient = "gray80", x = NULL, y = NULL, z = NULL)


agg %>%
  rowwise() %>%
  mutate(spheres = sphere1.f(X1, X2, X3, r=0.5## , col = "pink"
                             ))
#> # A tibble: 11 x 4
#> # Rowwise: 
#>        X1       X2      X3 spheres   
#>     <dbl>    <dbl>   <dbl> <rglLwlvl>
#>  1 -0.308  0.183   -0.713  15        
#>  2 -1.43   1.70    -0.0337 16        
#>  3  1.11  -0.993    0.0711 17        
#>  4 -0.418  2.22     1.61   18        
#>  5  0.524 -0.706   -2.30   19        
#>  6  0.521 -2.40     1.36   20        
#>  7  4.54  -0.566   -1.53   21        
#>  8  2.96  -0.362   -0.317  22        
#>  9  6.32   0.326   -1.69   23        
#> 10  3.79   0.603    1.23   24        
#> 11  5.36  -0.00168  2.31   25


segments3d(bond_segments, lwd=8, color="black")

^{由reprex 包( v2.0.0 ) 于 2021 年 7 月 21 日创建}

Answer 1

有几种方法可以做到这一点。 最简单的就是在每个球体旁边绘制文本：

text3d(agg, texts = LETTERS[1:11], adj = -2)

这种简单方法的问题在于球体会随着绘图调整大小，但文本和间距不会，因此如果您将绘图放大，标签将被隐藏。 要获得plotmath3d大小的标签，您需要使用plotmath3d绘图，例如

text3d(agg, texts = LETTERS[1:11], adj = -2, 
       usePlotmath = TRUE, fixedSize = FALSE)

这产生

它仍然不完美，因为最右边的标签丢失了； 这看起来像一个错误。 如果您对adj使用不同的值，例如c(0.5, 2)它可以工作。