Don't use 3D charts

Published on 2023-03-08 15:36

There is only one intentional reason to use 3D charts, hide things. In this post we'll take a look why.

Some art theory

One of the most important thing to understand when displaying 3D objects on paper or display is perspective. Perspective makes objects that are bigger appear as closer to us and smaller object further away. In the chart below can you safely and quickly identify which bar is the tallest one?

Readability

Second issue with 3D is that it's hard to read. In 3D everything is in space which includes grids and other lines that help us read the chart. This means that there is a space between displayed values and the grid. In the two pictures below there are two charts created from the same data.

When you compare the two charts, the second one should make you more sure about the values than the first one.

Pies

Spending time growing up in Czechia, pie charts like the one below were quite common on TV Nova. It shows the portion of adult population who watched TV between 7:30pm and 7:53pm.

To interpret this chart one needs some cultural context. Between 7pm and 8pm TV stations broadcast their main news program, Nova usually starts at 7:30pm.

Picking a sample in time is not wrong. What's wrong is that the slices are skewed and make it much harder to read it compared to 2D pie chart. Which is already hard to read.

Conclusion

Please, avoid 3D charts.