Draw multiple 3D boxes of different dimensions and

Question

Recently I stumbled over the rgl-Package in R, which can be used to create interactive 3d plots. Now I want to visualize a set of boxes in one 3d plot. A Box B has cartesian coordinates B_coord=[x,y,z], which correspond to the lower left back corner and dimensions B_dim=[x1,y1,z1].

Apparently it is easy to draw, scale and position some cubes with the following exemplary code:

open3d()
printBox <- function(x,y,z,x1,y1,z1) {
  mycube <- scale3d(cube3d(),x1,y1,z1)
  wire3d(translate3d(mycube,x,y,z))
}
printBox(0,0,0,1,1,1)

With this code the boxes are moved to x,y,z and scaled to x1,y1,z1. My question is how to write a similar function with the same input which positions the boxes by the coordinates of their lower left back corner and draws a box with the dimensions x1, y1, z1. I am not tied to the rgl package and R, but I like its interactive 3d view.

Thank you for your ideas!

Answer 1

I think your code already does that. So as to make it more clear, and explain what those rgl functions do, I unrolled your function and commented it and put it in a more illustrative example.

library(rgl)

open3d()

# create and plot a box at (x,y,z) of size (x1,y1,z1)
printBox <- function(x, y, z, x1, y1, z1) {
  mycube <- cube3d()                      # create a cube as mesh object   
  mycube <- scale3d(mycube, x1, y1, z1)   # now scale that object by x1,y1,z1
  mycube <- translate3d(mycube, x, y, z)  # now move it to x,y,z
  wire3d(mycube)                          # now plot it to rgl as a wireframe
}

# Display 5 boxes along a diagonal line
n <- 5
for (i in 1:n) {
  x <- i/n 
  y <- i/n
  z <- i/n
  sz <- 1/(2*n)
  printBox(x, y, z, sz,sz,sz )
}

axes3d()  # add some axes