Having just left the Theme Wizard, let's now pop back into it, so we can look at 3D backgrounds. This feature is still labeled as beta, and so it is possible that it could change, but for now, it will work as described in the following steps:
Using the Customize button on the top menu bar, open the side panel and then click on Advanced to launch the Theme Wizard as in the task we saw in the previous section.
In the bottom left-hand corner of the wizard, there is a button labeled Advanced; ensure this is selected and you are in the advanced theme editor.
The first option in this new window should be for 3D Background; click on Edit alongside it.
A new pop-up window will appear that will allow you to upload up to three different backgrounds; these will be layered in the order you upload them. As you zoom into the canvas, the first background layer will fade into the second and so on.
To upload a background layer, click on Upload and then browse for your file. Once you have found...