What I hope to achieve is to make the canvas tag of Cesium completely transparent, displaying only the objects that are drawn. The background of the canvas should also be transparent. However, the code I am using does not work

[jjspace]

You should be able to make the canvas transparent by setting the background color to transparent. Here’s a sandcastle showing that off: transparent background. Is this the effect you’re trying to achieve?

Just note you may see an extra black band around the earth with this method if you don’t turn the atmosphere off as shown in this issue