a hollow earth

I have a project in mind where I’d like the camera to travel inside a hollow globe. I’d like to have the option to display satellite imagery or vector data as it would appear from the interior. And, as I’m modeling a physical camera and mount with Blender, I would like to be able to cast its shadow onto the interior surface.

Searches of the group archive aren’t returning relevant results, at least not for the terms I’m using.

Is this something that can be done using Cesium? Are there alternative libraries that might be better suited to this admittedly unusual use case?

Thanks for any insights.


I know you folks are shepherding the latest release but is this a difficult question?

This sounds like an interesting application! What kind of project is this for? Is the goal to essentially be looking at the same satellite imagery…but as if the camera was in the center of the Earth?

There’s currently a few assumptions in the engine that prevent underground rendering from working (such as the camera controller not allowing the camera to go underground, which you can disable. But also the renderer will cull objects completely underground since they are considered not visible, which is harder to work around). We are working on improving support for this generally but I don’t have a specific timeline for it at the moment. There’s some more discussion in this GitHub issue: https://github.com/AnalyticalGraphicsInc/cesium/issues?utf8=%E2%9C%93&q=is%3Aissue+is%3Aopen+underground

You might have more luck creating an ellipsoid geometry and and texturing it. You’d need to enable backface culling to be able to see it from the inside, which might require working with a bit of the lower level primitive APIs.

Hi Omar,

I have an ongoing project where I use what I see as the creative impulses behind certain experimental films (or filmmakers) as jumping off points for animated maps. I’m basically asking: if we took the 16mm cameras away from experimental filmmakers and gave them instead tools like Mapbox GL, Cesium, OpenMapTiles, PostGIS what would they have made instead?

You’ve understood the goal of one of these pieces and I appreciate your suggestions and pointers.