Drawing custom objects around billboards

Hi everyone, I'm trying to add some additional images around my billboards that need to be generated dynamically, and I'm having a hard time figuring out how to do that. For example, I would like to draw an arc around my billboard that represents the amount of fuel that has been used (as a percentage). So if 50% of the fuel is gone, my arc will go halfway around the billboard. Also, I need to be able to make custom labels that require styling beyond what is available in the Label object. I would also like to be able to have the user interact with those things (so clicking on the fuel status arc would trigger something, etc).

I don't think I can use the built-in drawing capabilities for the arc (using splines, for example) because it seems like they're represented geographically, and therefore, when I zoom in, the arc gets bigger in relation to my billboard.

It seems like the easiest way for me to be able to accomplish this would be to have a way to insert a dynamically generated SVG at the same location as my normal billboard for the arc, and HTML for my custom label. The reason I want to use a dynamically generated SVG is because I need each item on my Cesium map to have its own fuel status representation, and I want it to be pretty accurate, and I need to be able to change the colors depending on if the fuel is low, etc.

I started down that path by trying to inserta data URI containing HTML into the billboard's image field (in my CZML), but it does not display anything. I figured if I could do that, then I could just create another billboard in addition to the one representing the aircraft that would have the HTML (or even better, an SVG path). Note that when I put a base64 string representation of a png as the billboard, it does work - just not when I try to use HTML or plain text instead, such as:


Can anyone tell me what my options are for creating custom markup/images around my billboards?

Also wanted to add that while my example up there was html, I'd really like to just be able to add SVG instead, so something like this:

“data:image/svg+xml,<svg viewBox=‘0 0 40 40’ height=‘25’ width=‘25’
xmlns=‘http://www.w3.org/2000/svg’><path fill=‘rgb(91, 183, 91)’ d=‘M2.379,

When I add that to the Sandcastle code, it doesn't display the test image.