Sometimes you may want to include more complex patterns of interactivity into a plot, for example where interaction with one plot elements triggers changes or appearance / disappearance in a wider group of other plot elements.

In this case you can utilise the ability to group elements in a plot, so that interaction with any one of the group elements that has been indicated as interactive with the argument interactive = TRUE will trigger changes as specified by highlight in all other plot elements in the same group.

The example below builds up a plot with more complex interactivity based on these principles.

# Set data
x_vals <- iris$Sepal.Length
y_vals <- iris$Sepal.Width
z_vals <- iris$Petal.Length
point_cols <- rainbow(3)[iris$Species]

# Setup plot
data3js <- plot3js(
  x = x_vals,
  y = y_vals,
  z = z_vals,
  xlab = "Sepal Length",
  ylab = "Sepal Width",
  zlab = "Petal Length"
)

# Add points for each point
for (n in seq_along(x_vals)) {

  # Set a record of point ids you're going to group
  point_ids <- c()

  # Add the 3d point
  data3js <- points3js(
    data3js,
    x = x_vals[n],
    y = y_vals[n],
    z = z_vals[n],
    col = point_cols[n],
    size = 1,
    highlight = list(
      size = 2
    ),
    interactive = TRUE
  )

  point_ids <- c(point_ids, lastID(data3js))

  # Add the point on the x- face
  data3js <- points3js(
    data3js,
    x = data3js$lims[[1]][1] + 0.001,
    y = y_vals[n],
    z = z_vals[n],
    col = point_cols[n],
    shape = "circle",
    size = 1,
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    rotation = c(0, 90, 0),
    face = "x-"
  )

  point_ids <- c(point_ids, lastID(data3js))

  # Add the point on the x+ face
  data3js <- points3js(
    data3js,
    x = data3js$lims[[1]][2] - 0.001,
    y = y_vals[n],
    z = z_vals[n],
    col = point_cols[n],
    size = 1,
    shape = "circle",
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    rotation = c(0, 90, 0),
    face = "x+"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the x- face
  data3js <- lines3js(
    data3js,
    x = c(data3js$lims[[1]][1], x_vals[n]),
    y = c(y_vals[n], y_vals[n]),
    z = c(z_vals[n], z_vals[n]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "x-"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the x+ face
  data3js <- lines3js(
    data3js,
    x = c(x_vals[n], data3js$lims[[1]][2]),
    y = c(y_vals[n], y_vals[n]),
    z = c(z_vals[n], z_vals[n]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "x+"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the point on the y- face
  data3js <- points3js(
    data3js,
    x = x_vals[n],
    y = data3js$lims[[2]][1] + 0.001,
    z = z_vals[n],
    col = point_cols[n],
    size = 1,
    shape = "circle",
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    rotation = c(90, 0, 0),
    face = "y-"
  )

  point_ids <- c(point_ids, lastID(data3js))

  # Add the point on the y+ face
  data3js <- points3js(
    data3js,
    x = x_vals[n],
    y = data3js$lims[[2]][2] - 0.001,
    z = z_vals[n],
    col = point_cols[n],
    size = 1,
    shape = "circle",
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    rotation = c(90, 0, 0),
    face = "y+"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the y- face
  data3js <- lines3js(
    data3js,
    x = c(x_vals[n], x_vals[n]),
    y = c(data3js$lims[[2]][1], y_vals[n]),
    z = c(z_vals[n], z_vals[n]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "y-"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the y+ face
  data3js <- lines3js(
    data3js,
    x = c(x_vals[n], x_vals[n]),
    y = c(y_vals[n], data3js$lims[[2]][2]),
    z = c(z_vals[n], z_vals[n]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "y+"
  )

  point_ids <- c(point_ids, lastID(data3js))



  # Add the point on the z- face
  data3js <- points3js(
    data3js,
    x = x_vals[n],
    y = y_vals[n],
    z = data3js$lims[[3]][1] + 0.001,
    col = point_cols[n],
    size = 1,
    shape = "circle",
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    face = "z-"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the z- face
  data3js <- lines3js(
    data3js,
    x = c(x_vals[n], x_vals[n]),
    y = c(y_vals[n], y_vals[n]),
    z = c(data3js$lims[[3]][1], z_vals[n]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "z-"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the line to the z+ face
  data3js <- lines3js(
    data3js,
    x = c(x_vals[n], x_vals[n]),
    y = c(y_vals[n], y_vals[n]),
    z = c(z_vals[n], data3js$lims[[3]][2]),
    lwd = 0,
    highlight = list(
      lwd = 2
    ),
    face = "z+"
  )

  point_ids <- c(point_ids, lastID(data3js))


  # Add the point on the z+ face
  data3js <- points3js(
    data3js,
    x = x_vals[n],
    y = y_vals[n],
    z = data3js$lims[[3]][2] - 0.001,
    col = point_cols[n],
    size = 1,
    shape = "circle",
    opacity = 0.2,
    highlight = list(
      size = 2,
      opacity = 1
    ),
    interactive = TRUE,
    depthWrite = FALSE,
    face = "z+"
  )

  point_ids <- c(point_ids, lastID(data3js))

  # Now group all the points you've added
  data3js <- group3js(data3js, point_ids)

}

# View the plot
r3js(data3js)