A shape layer, solid or any layer. I can't find a way to activate them. I have a camera, the layer is 3d, a light even. No reflection options in the latest version
That option is available only with Ray–traced rendering enabled. Beware of exceedingly long render times and other restrictions on masking and effects when Ray–traced rendering option is turned on. There is a warning that pops up when you enable that feature. Carefully read and understand it.