A three-dimensional bar chart where bars rise from a 2D categorical grid, with height encoding the measured value. Two categorical axes define the grid position on the base plane while the vertical axis shows magnitude. This visualization extends the bar chart family into 3D space, making it effective for comparing values across two categorical dimensions simultaneously.
# anyplot.ai
# bar-3d-categorical: 3D Bar Chart for Categorical Comparison
# Library: makie 0.21.9 | Julia 1.11.9
# Quality: 84/100 | Created: 2026-09-04
using CairoMakie
using Colors
using Random
Random.seed!(42)
# Theme tokens (see prompts/default-style-guide.md "Background" + "Theme-adaptive Chrome")
THEME = get(ENV, "ANYPLOT_THEME", "light")
PAGE_BG = THEME == "light" ? colorant"#FAF8F1" : colorant"#1A1A17"
INK = THEME == "light" ? colorant"#1A1A17" : colorant"#F0EFE8"
INK_SOFT = THEME == "light" ? colorant"#4A4A44" : colorant"#B8B7B0"
# Imprint continuous colormap — single-polarity (revenue magnitude has no natural midpoint)
IMPRINT_SEQ = [colorant"#009E73", colorant"#4467A3"]
# Data — quarterly revenue by product category and sales region
product_categories = ["Electronics", "Apparel", "Home & Garden", "Sports", "Books"]
regions = ["North", "South", "East", "West"]
n_products = length(product_categories)
n_regions = length(regions)
base_revenue = [82.0, 61.0, 48.0, 55.0, 39.0]
region_factor = [1.15, 0.85, 1.00, 0.95]
revenue = Array{Float64}(undef, n_products, n_regions)
for i in 1:n_products, j in 1:n_regions
revenue[i, j] = base_revenue[i] * region_factor[j] + randn() * 4
end
# Plot — see default-style-guide.md "Visual Sizing Defaults" for the canvas + sizing values
fig = Figure(size = (1600, 900), fontsize = 14, backgroundcolor = PAGE_BG)
ax = Axis3(
fig[1, 1];
title = "bar-3d-categorical · julia · makie · anyplot.ai",
titlesize = 20,
titlecolor = INK,
xlabel = "Product Category",
ylabel = "Region",
zlabel = "Revenue (\$k)",
xlabelsize = 14,
ylabelsize = 14,
zlabelsize = 14,
xlabelcolor = INK,
ylabelcolor = INK,
zlabelcolor = INK,
xticklabelsize = 12,
yticklabelsize = 12,
zticklabelsize = 12,
xticklabelcolor = INK_SOFT,
yticklabelcolor = INK_SOFT,
zticklabelcolor = INK_SOFT,
xticks = (1:n_products, product_categories),
yticks = (1:n_regions, regions),
azimuth = deg2rad(225), # spec calls for ~45°; 225° keeps the tallest bars in front, unoccluded
elevation = deg2rad(30),
backgroundcolor = PAGE_BG,
xypanelcolor = PAGE_BG,
xzpanelcolor = PAGE_BG,
yzpanelcolor = PAGE_BG,
xgridcolor = RGBAf(INK.r, INK.g, INK.b, 0.15),
ygridcolor = RGBAf(INK.r, INK.g, INK.b, 0.15),
zgridcolor = RGBAf(INK.r, INK.g, INK.b, 0.15),
xspinecolor_1 = INK_SOFT, xspinecolor_2 = INK_SOFT, xspinecolor_3 = INK_SOFT,
yspinecolor_1 = INK_SOFT, yspinecolor_2 = INK_SOFT, yspinecolor_3 = INK_SOFT,
zspinecolor_1 = INK_SOFT, zspinecolor_2 = INK_SOFT, zspinecolor_3 = INK_SOFT,
protrusions = 70,
)
# Bar bases sit on a unit grid; markersize < 1 in x/y leaves a gap between neighbors for depth cues
bar_gap = 0.2
bar_positions = Point3f[]
bar_sizes = Vec3f[]
bar_values = Float64[]
for i in 1:n_products, j in 1:n_regions
push!(bar_positions, Point3f(i - (1 - bar_gap) / 2, j - (1 - bar_gap) / 2, 0))
push!(bar_sizes, Vec3f(1 - bar_gap, 1 - bar_gap, revenue[i, j]))
push!(bar_values, revenue[i, j])
end
meshscatter!(
ax, bar_positions;
marker = Rect3(Point3f(0, 0, 0), Vec3f(1, 1, 1)),
markersize = bar_sizes,
color = bar_values,
colormap = IMPRINT_SEQ,
colorrange = extrema(bar_values),
# Directional lighting on adjacent instanced Rect3 faces causes a
# visible z-fight crease on tall bars near the axis corner; flat
# per-value color reads more accurately against the Colorbar anyway.
shading = NoShading,
)
Colorbar(
fig[1, 2];
limits = extrema(bar_values),
colormap = IMPRINT_SEQ,
label = "Revenue (\$k)",
labelcolor = INK,
ticklabelcolor = INK_SOFT,
tickcolor = INK_SOFT,
)
colsize!(fig.layout, 1, Relative(0.85))
# Save
save("plot-$(THEME).png", fig; px_per_unit = 2)
Runnable source as JSON, for any HTTP client: https://api.anyplot.ai/specs/bar-3d-categorical/makie/code. Any spec id and library id listed in llms-full.txt fit the same URL shape; every URL below is complete and callable.
{
"spec_id": "bar-3d-categorical",
"language": "julia",
"library": "makie",
"page": "https://anyplot.ai/bar-3d-categorical/julia/makie",
"hub": "https://anyplot.ai/bar-3d-categorical",
"code_json": "https://api.anyplot.ai/specs/bar-3d-categorical/makie/code",
"spec_json": "https://api.anyplot.ai/specs/bar-3d-categorical",
"render_light_png": "https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/julia/makie/plot-light.png",
"render_dark_png": "https://storage.googleapis.com/anyplot-images/plots/bar-3d-categorical/julia/makie/plot-dark.png",
"quality_score": 84.0,
"license": "MIT",
"guide": "https://anyplot.ai/llms.txt"
}Part of 3D Bar Chart for Categorical Comparison on anyplot.ai.