Refraction with spotlights

Hi, I can’t manage to get the refraction effect when a spotlight passes through a translucent refractive material and ends against another opaque surface.
Any clue if it is a matter of material settings, spotlight settings, general settings?
I’m using U4.20, product viewer blueprint, testing in VR.

UE4 doesn’t support caustics. The only way I’ve seen caustics done is with baked decals (look at Evermotion) and Ryan Brucks’ shader wizardry (uses heightmaps.)