The small reflective sphere in the center is a LightProbe.
That’s a new type of Light (on the PBRIsComing branch only) that is used for environment lighting.
It has a position, and a bounding volume (for now only bounding sphere is supported)
Here you can see the gizmo in the SDK with a smaller radius :
Note how the radius influence the lighting.
There is still a huge amount of work to do for propper PBR support, but I though I’d give some heads up.
We’re currently focusing on fixing the editor for content and scripting since we’re storing model definitions and item configuration in JSON files and using callbacks in JavaScript for game logic and AI.