what sort of reflection is it? and what sort of effect is it supposed to have?
i picture a horror game right there.
on planes (floors and walls) you could potentially fake it putting it on the ground and render it upside down aka mirrored and use a transparency hack. without depthtest it would always render and you gotta do some fancy shader magic to control the look of it.
for regular graphics you’d have to render it controlled into a rendertarget and composite it. i’m not sure exactly howto do that. i’d have to try that.