General Lighting Q: How do I get the local geometry to influence lighting?

I'm using 2019.1 and HDRP in a basic scene using the HDRP Template. The only change I have done is I have added an HDR sky.

I'm just experimenting but I have a question...

When I have added a simple sphere with a material on it, it is lit from the "environment", in this case the HDR skybox. It looks fine:


But when I add a plane and add the same material, the sphere is still lit only by the sky box, including from below:


The (fresnel effect?) wraps around all of the edges in what looks correct for the skybox only as the environment, but when set in a different environment, I'd like the lower edge to be affected by the plane below it. The bright environment on the edge of the sphere looks out of place in the image above.

How do I get around this issue? Is this a case of: Reflection Probes (which I don't have yet) or Light Probes (none of those either)?

Please feel free to point me to the relevant documentation or tutorial. Or just beat me with a wet noodle for being an idiot (if you tell me what I've missed...)

 

Reflection probes, light probes, and screen-space reflections if possible. But basically this is currently not a solved problem. Raytracing should be able to solve it eventually but good solutions are probably still a few years away.