9 Rendering the R logo in Minecraft

As a further illustration of use of the miner package to interact with Minecraft from R, here I will render the R logo within Minecraft.

9.1 Load and prepare an image file

First, let’s download the image file from the web. We’ll load it directly into R from the web using the imager package.

library(imager)
url <- "https://www.r-project.org/logo/Rlogo.png"
logo <- load.image(url)

Print to see the size of the image.

logo

## Image. Width: 724 pix Height: 561 pix Depth: 1 Colour channels: 4

The image is stored as a 4-dimensional array: horizontal and vertical position, time, and color.

dim(logo)

## [1] 724 561   1   4

Let’s reduce the size to 80x70.

logo <- resize(logo, 80, 70)

There is a bit of shading in the logo, but mostly there are three colors: transparent, gray, and blue. If we look at a histogram of the first color channel (red), we can see the three pieces:

par(mar=c(5.1,4.1,0.6,0.6), las=1)
hist(logo[,,,1], breaks=100, main="",
     xlab="Red color intensity")

So let’s truncate at 0.05 and 0.4.

logo[] <- cut(logo, c(-Inf, 0.05, 0.4, Inf))
logo <- logo[,,1,1]

9.2 Render in Minecraft

Now let’s load the miner package, connect to the MineCraft server, and find a spot to place the logo.

library(miner)
mc_connect()
host_pos <- getPlayerPos()
host_pos[2] <- host_pos[2] + 10

Now let’s render the R logo using gray and blue wool, leaving parts transparent.

First, we pick out the blue and gray wool blocks, to get the item and style IDs.

blue <- find_item("Blue Wool")
gray <- find_item("Light Gray Wool")

Now we try rendering the logo.

for(i in 1:nrow(logo)) {
    for(j in 1:ncol(logo)) {
        if(logo[i,j] == 2)
            setBlock(host_pos[1]+(nrow(logo)-i),
                     host_pos[2]+(ncol(logo)-j),
                     host_pos[3],
                     blue[2], blue[3])
        if(logo[i,j] == 3)
            setBlock(host_pos[1]+(nrow(logo)-i),
                     host_pos[2]+(ncol(logo)-j),
                     host_pos[3],
                     gray[2], gray[3])
    }
}

The result looks like this: