One more for the road.
A small note on the model; you need to cut holes in the surface of the whiskey where the icecubes are, if you are using an physically accurate engine.
On the other hand this is actually a situation that render engines(atleast Maxwell) can“t get physically right. When light first enters from air to ice and then into whiskey, that ray of light will think it is in air, as it passed thru the backface of ice (not thru the frontface of whiskey). Still, the difference is probably very hard to see...



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