e_grid_3d(e, index = 0, ...)

# phony data
v <- LETTERS[1:10]
matrix <- data.frame(
  x = sample(v, 300, replace = TRUE),
  y = sample(v, 300, replace = TRUE),
  z1 = rnorm(300, 10, 1),
  z2 = rnorm(300, 10, 1),
  stringsAsFactors = FALSE
) %>%
  dplyr::group_by(x, y) %>%
  dplyr::summarise(
    z1 = sum(z1),
    z2 = sum(z2)
  ) %>%
  dplyr::ungroup()

trans <- list(opacity = 0.4) # transparency
emphasis <- list(itemStyle = list(color = "#313695"))

matrix %>%
  e_charts(x) %>%
  e_bar_3d(y, z1, stack = "stack", name = "Serie 1", itemStyle = trans, emphasis = emphasis) %>%
  e_bar_3d(y, z2, stack = "stack", name = "Serie 2", itemStyle = trans, emphasis = emphasis) %>%
  e_grid_3d(splitLine = list(lineStyle = list(color = "blue")))